ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (109)
  • gene expression  (65)
  • pH  (44)
  • Springer  (109)
  • American Chemical Society
  • American Meteorological Society
  • 1995-1999  (109)
  • 1990-1994
  • 1965-1969
  • 1955-1959
  • 1950-1954
  • 1995  (109)
  • 1953
  • 1950
  • 1
    Electronic Resource
    Electronic Resource
    The stability of 12-molybdosilicic, 12-tungstosilicic, 12-molybdophosphoric and 12-tungstophosphoric acids in aqueous solution at various pH (1995)
    Springer
    Catalysis letters 34 (1995), S. 237-244 
    Details
    ISSN: 1572-879X
    Keywords: metal-oxygen cluster compounds ; heteropoly acids ; stability ; pH ; aqueous solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stabilities of the solid superacids H3Mo12O40, H3PW12O40, H4SiMo12O40 and H4SiW12O40 in aqueous solution have been measured at various values of pH by use of ion chromatographic analyses. The aforementioned acids are completely decomposed at values of pH, 4.0, 5.2, 7.0 and 11.0, respectively. The stabilities in aqueous solution with respect to pH follow the order H4SiW12O40 〉 H3PW12O40 〉 H4SiMo12O40 〉 H3PMo12O40.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00808338
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Analysis of gene function inDictyostelium (1995)
    Springer
    Cellular and molecular life sciences 51 (1995), S. 1116-1123 
    Details
    ISSN: 1420-9071
    Keywords: Antisense RNA ; gene expression ; insertional mutagenesis ; physical mapping ; reporter genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Over the past ten years, powerful molecular genetic techniques have been developed to analyze gene function inDictyostelium. DNA-mediated transformation using a variety of selections and vectors has allowed the introduction of wild-type or modified genes that are under various forms of transcriptional control. Homologous recombination is efficient and can be used to modify the genome in precise ways. In addition, it is now possible to clone genes based on their mutant phenotype alone, either by insertional mutagenesis, or by screening antisense expression cDNA libraries. Finally, a nearly complete physical map of the genome is available and so genes are easily mapped by physical techniques. We discuss many of these advances within the context of major research problems presently under study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01944729
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Regulation of metallothionein gene expression in Cd- or Zn-adapted RK-13 cells (1995)
    Springer
    Cellular and molecular life sciences 51 (1995), S. 606-611 
    Details
    ISSN: 1420-9071
    Keywords: Metallothionein ; isometallothioneins ; gene expression ; rabbit kidney cell-line ; cadmium adaptation ; zinc adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We explored the molecular genetics underlying the massive induction of isoMTs by Zn2+ or Cd2+ in metal tolerant rabbit kidney (RK-13) sub-line cells, using band shift assays and Southern blotting analysis. In sub-line cells accommodated to intermediate metal concentrations (100 μM Zn2+; 1–20 μM Cd2+) evidence suggested that the increase in the capacity for isoMT synthesis is brought about by an increased binding activity of the nuclear transcription factors MTF-1 and Sp1. Using quantitative band shift analysis with a mouse MRE-d oligonucleotide probe, the binding of both transcription factors was found to be enhanced two to three times over the binding activity measured in the unexposed parental RK-13 cells. Their increase in binding activity is probably the cause of the overexpression of MT genes and the development of metal tolerance in these cells. In cells tolerant to the highest concentrations of metal the analysis of Southern blot signals revealed MT gene amplification to be the most probable cause of the increased MT production. Thus, in cells of sub-lines growing in the presence of 350 μM Zn2+, two of the isoMT genes were coordinately triplicated and in cells tolerant to 150 μM Cd2+ one isoMT gene was amplified two-fold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02128753
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Soil microbial biomass and organic matter composition in soils under cultivation (1995)
    Springer
    Biology and fertility of soils 19 (1995), S. 197-202 
    Details
    ISSN: 1432-0789
    Keywords: Soil organic matter ; Cultivation ; CPMAS 13C-NMR ; Microbial biomass ; Substrate-induced respiration ; Alkylic carbon ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract To determine whether there is a relationship between the composition of soil organic matter and the activity of the soil microbial biomass, the composition of the organic matter in 12 typical arable soils in Northwest Germany was investigated by wet chemical analysis and CPMAS cross polarization magic angle spinning 13C-NMR spectroscopy. The data were correlated with the microbial biomass as estimated by substrate-induced respiration. A strong correlation between the microbial biomass and alkylic C compounds was observed (r=-0.960***). Recalcitrant substances were enriched in this fraction, which were classified as humic acids according to the wet chemical procedure. The microbial decomposition of these humic acids is probably retarded, due to their chemical structure and/or physical bonding, when the soil microbial biomass activity is limited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336159
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Proton-activated currents in chick spinal motoneurons (1995)
    Springer
    Journal of comparative physiology 177 (1995), S. 503-510 
    Details
    ISSN: 1432-1351
    Keywords: pH ; Patch clamp ; Glutamate receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Proton-activated currents were examined in patch-clamp recordings from embryonic chick motoneurons. Rapid application of protons evoked a large inward current that peaked and then decayed, presumably due to channel inactivation. A pH shift from 7.4 to 7.1 was sufficient to evoke detectable currents. The shift from pH 7.4 required for half-maximal current amplitude (EC50) was to pH 6.8. In single-channel recordings, activation was achieved within 6 ms at pH 7. The average channel open time was 1.4 ms; the closed-state time constants were 1.0 and 6.2 ms. At pH 6.5, the single-channel conductance was 22 pS, and the reversal potential was similar to the calculated Na+ equilibrium potential. Current amplitude declined by 49% following addition of Ni2+ and increased by 58% as Ca2+ was lowered from 2 to 0.1 mM. Inactivation time constants ranged from 90 to 200 ms as pH varied from 6 to 7; these values did not depend on membrane potential. The reactivation time constant was 22 s. Proton- and glutamate-activated currents summated. Thus, transient decreases in extracellular pH can evoke large inward currents that decay rapidly and reactivate slowly. These currents may occur under pathological conditions that affect extracellular pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00187485
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Aminated polystyrene membranes for a fiber optic pH sensor based on reflectance changes accompanying polymer swelling (1995)
    Springer
    Microchimica acta 121 (1995), S. 41-50 
    Details
    ISSN: 1436-5073
    Keywords: polystyrene membranes ; fiber optics ; pH ; reflectance ; aminated polystyrene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We have prepared toughened, porous, aminated polystyrene membranes that undergo an increase in reflectance as the pH increases from 6.8 to 8.0. Vinylbenzyl chloride (VBC) is copolymerized with divinylbenzene (DVB) in the presence of a toughening agent, Kraton G1652, a styrene-ethylene, butylene-styrene triblock copolymer, and a porogenic solvent, xylene/ dodecane. The optimum formulation for sensing is 2% DVB (mol DVB/mol VBC), 2% Kraton (g Kraton/g VBC) and 40% (v/v) 2∶1 xylene: dodecane. Benzoyl peroxide is used as the initiator. The components are partially polymerized at 85 °C to a viscosity of 600–800 centipoise. The polymerization is then stopped by reducing the temperature. A drop of the partially polymerized solution is confined between two microscope slides and the polymerization reaction is completed. The resulting membrane is then swollen in 1,4-dioxan and reacted with diethanolamine. These membranes have been incorporated into a pH sensor based on changes in reflected intensity measured through a bifurcated bundle of twenty unbuffered 50/55 core/cladding glass-on-glass optical fibers with numerical apertures of 0.57. The resulting sensor is stable and requires inexpensive optical components, a red-emitting LED as the source and a silicon photodiode as the detector.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01248239
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Orthophosphate solubility in waters of different ionic composition (1995)
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 73-78 
    Details
    ISSN: 1573-0867
    Keywords: P precipitation ; precipitation kinetics ; P solubility diagram ; pH ; octacalcium phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Orthophosphate (OP) is a major component of irrigation and nutrient solutions. Since OP precipitates may clog drippers, and deviations from intended OP concentrations may adversely affect plant development and yield, an understanding of the mechanisms controlling OP solubility in solutions of various ionic compositions, is essential. The objectives of this study were (i) to suggest guidelines for permitted OP additions to waters of various ionic compositions, so as to avoid OP crystallization and (ii) to predict the decrease in OP concentration as a function of time in supersaturated solutions. Five freshwater sources, used for irrigation in Israel, and representing extremes of pH and of Ca, HCO3 and SO4 concentrations, were tested. Solutions of three different initial OP concentrations (10, 30 and 90 mg Pl−1) and two pH values were prepared in 21 plastic bottles and kept in a dark room at 27 °C. Solution samples were withdrawn from the bottles at predetermined times, filtered and analysed for pH and total OP, Ca and HCO3 concentrations. In all the studied waters and for all initial OP levels the OP concentration (Cp) declined with time. The rate of decrease in Cp was proportional to the difference between the observed and equilibrium Cp values, with a specific rate constant for each water.The pH and the Ca2+ and HCO 3 − activities in solution were influenced by the initial Cp. The equilibrium Cp in all treatments was found to be controlled by octacalcium phosphate (OCP). Available chemical equilibria models allow to calculate the maximum level of OP that can be added to various waters before OCP precipitates, based on water pH and Ca, HCO3 and SO 4 2− concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750694
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Phosphorus sorption by three cultivated savanna alfisols as influenced by pH (1995)
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 107-112 
    Details
    ISSN: 1573-0867
    Keywords: exchangeable Al ; exchangeable Ca ; ion pairs ; P sorption ; pH ; precipitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An earlier study of phosphate sorption by some savanna soils from Nigeria suggested that increased P sorption when pH was raised might be due to precipitation of exchangeable Al as amorphous polymeric Al species with increased sorption sites. But these savanna soils have Ca as the dominant cation in their exchange sites, and low exchangeable Al. The objective of this study was to determine the role played by Ca in pH-induced P sorption of three savanna soils under continuous cultivation. Phosphorus sorption increased when pH was raised from 4.5 to 7.0. Similarly, Ca retention increased with increasing pH. Regression of P sorption on Ca retention indicated a significant linear relationship in the three soils. Three possible mechanisms were proposed to explain the increasing P sorption with increasing pH: precipitation of Ca-phosphates, Ca-induced P sorption or co-adsorption of Ca and H2PO 4 − or HPO 4 2− as ion pairs or complexes. Available evidence suggests that all three mechanisms can operate together to enhance P retention as pH increases. The paper proposes that increased P sorption by savanna soils when pH is raised is likely to be related to the chemistry and retention of Ca rather than to hydrolytic reactions of Al.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750799
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    A modified urea based NP fertilizer: urea-TSP-MAP combinations (1995)
    Springer
    Nutrient cycling in agroecosystems 45 (1995), S. 217-220 
    Details
    ISSN: 1573-0867
    Keywords: ammonia volatilization ; monoammonium phosphate ; pH ; urea triple superphosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Applying urea with acidic phosphate fertlizer increases urea fertilizer efficiency by reducing ammonia volatilization and toxicity to crop from urea hydrolysis. However, urea and triple superphosphate (TSP) are not recommended to be cogranulated because blends might become wet and sticky. Monoammonium phosphate (MAP) is a less acidic P source than TSP, but is compatible with urea. The objective of this study was to evaluate compound NP fertilizer products made from MAP and TSP combinations as P sources with urea. Fertilizer mixtures were pelletized from commercial urea, TSP and MAP with different N:P2O5 ratios and MAP/TSP combinations. Moisture changes during storage, pH of fertilizer solutions, and ammonia volatilization from surface applied fertilizer pellets were measured. Using MAP with TSP in urea-P mixtures reduced moisture increases during storage. Increasing MAP in urea-TSP-MAP combinations increased fertilizer solution pH by over 1 unit as the MAP/TSP-P2O5 ratio increased from 0/100 to 100/0. Adding MAP as 50% of P in urea-MAP-TSP mixtures at 3:1 and 1.5: (N:P2O5) ratios reduced ammonia loss from urea 50% to 60% compared to urea alone; and ammonia loss was similar to that of urea-TSP combinations. A urea-TSP-MAP fertilizer combination could make efficient use of urea-N by crops by reducing ammonia loss from urea hydrolysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00748592
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Leaf litter processing and exoenzyme production on leaves in streams of different pH (1995)
    Springer
    Oecologia 102 (1995), S. 460-466 
    Details
    ISSN: 1432-1939
    Keywords: Detrital processing ; Exoenzymes ; ATP ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined microbial colonization, exoenzyme activity, and processing of leaves of yellow poplar (Liriodendron tulipifera), red maple (Acer rubrum), and white oak (Quercus alba) in three streams on the Allegheny Plateau of West Virginia, United States. Leaf packs were placed in streams that varied in their underlying bedrock geology, and therefore in their sensitivity to the high level of acidic precipitation that occurs in this region. The mean pH of the streams was 4.3 in the South Fork of Red Run (SFR), 6.2 in Wilson Hollow Run (WHR), and 7.7 in the North Fork of Hickman Slide Run (HSR). Through time, the patterns of microbial biomass and exoenzyme activity were generally similar among leaf species, but the magnitude of microbial biomass and exoenzyme activity differed among leaf species. Pectinase activity was greatest in HSR, the most alkaline stream, whereas the activity of exocellulase and xylanase was greatest in WHR and SFR, the intermediate and acidic streams. This variation in the activity of different exoenzymes was consistent with published pH optima for these exoenzymes. Variation in processing rates, both among leaf species and among streams, seems to be related to the level of microbial exoenzyme activity on the leaf detritus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341358
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Effect of carbon source and pH of the growth medium on spore germination in Phycomyces blakesleeanus (1995)
    Springer
    Archives of microbiology 164 (1995), S. 231-234 
    Details
    ISSN: 1432-072X
    Keywords: Key words Spore activation ; Phycomyces ; Carbon source ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phycomyces blakesleeanus sporangiospores responded differently to activation by physical and chemical stimuli. Spores that were physically (heat shock) activated or chemically (ammonium acetate) activated germinated and grew at pH 4.5 with the hexoses glucose, fructose, galactose, and N-acetylglucosamine, and with glycerol and amino acids. Under these conditions, physically activated spores showed a lower, although significant growth with the hexoses fructose, galactose, N-acetylglucosamine and with glycerol. On the other hand, physically activated spores incubated at alkaline pH (pH 7.3) required glucose to germinate; a requirement not observed with chemically activated spores, which showed significant growth in the other hexoses tested. Both physically and chemically activated spores incubated at pH 7.3 were unable to germinate and grow with amino acids and glycerol. These results suggest that there are different targets for activation of the spores by physical and chemical treatments. The levels of the fermentative enzymes alcohol dehydrogenase and lactate dehydrogenase and of the oxidative enzyme NAD+-isocitrate dehydrogenase were higher in cells grown at pH 4.5 in medium containing glucose; however, alcohol dehydrogenase and lactate dehydrogenase appear not to be affected by a change in the pH of the growth medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002030050259
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Cations adsorbed to soil organic matter — A regulatory factor for the release of organic carbon and hydrogen ions from soils to waters (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 1095-1100 
    Details
    ISSN: 1573-2932
    Keywords: acidity ; aluminium ; metal cations ; pH ; soil organic carbon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Surface waters in northern forest ecosystems receive a substantial amount of drainage water from superficial soil horizons enriched in organic matter (SOM). Chemical reactions in the interface between the soil solution andf organic colloides will therefore affect the surface water chemistry. The mobilization of total organic carbon (TOC) and pH was studied as a function of amounts of organically adsorbed Na, Ca and Al in two O and one A horizon, which differed in the likelihood of contributing to the chemistry in runoff, in a forested watershed in northern Sweden. The samples were hydrogen ion saturated, washed and titrated with NaOH, Ca(OH)2 and Al(OH)3 in a constant ionic medium of 0.01 M NaCl in order to give rise to a population of manipulated samples differing in the composition of adsorbed cations. The highly humified SOM accumulated in the Oh and Ah horizons of a Gleysol close to the draining stream was stabilized by flocculating Al (95% of adsorbed metal cations), which resulted in a low release of TOC. These horizons showed a high potential of organic carbon solubility when Al was changed for di- or monovalent cations. Calculations suggested that the release of TOC would increase more than ten times if Al was exchanged for Ca upon liming to pH 6.0. The pH values of all horizons were shown to be determined mainly by the composition of adsorbed mono-,di- and trivalent cations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00477127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Snowpack quality as an indicator of air pollution in Finnish Lapland and the Kola Peninsula, NW Russia (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 2185-2190 
    Details
    ISSN: 1573-2932
    Keywords: Cu ; Cu-Ni smelters ; Kola Peninsula ; Lapland ; Ni ; pH ; S ; snowpack
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Bulk snow samples were collected from the snowpack in open areas along two sampling lines running to the west from the Cu-Ni smelters at Nikel and Monchegorsk, NW Russia, during 1991–1993. The aim of the study was to estimate the area affected by sulphur and heavy metal deposition from the smelters. Snowpack quality was used as an indicator of deposition during winter time. The total sulphur, copper and nickel concentrations in the snowpack decreased significantly (p〈0.001) with increasing distance from the smelters along the sampling line running directly to the west from Monchegorsk. The deposition pattern was similar each winter during 1991–1993. The pH values did not correlate with the corresponding sulphur concentrations, and there was no decreasing pH gradient in the snowpack on moving towards Monchegorsk. The effects of sulphur emissions from Monchegorsk on snowpack chemistry were not detectable on the Finnish side of the border. The 3-year mean of the total sulphur concentration was 0.27 mg/kg, and of the pH values 4.92, along the sampling line running to the west of Monchegorsk. The total sulphur concentrations near the smelters (〈 20 km) varied between 0.37 and 0.95 mg/kg. The effect of the Cu-Ni smelters at Nikel on snowpack quality was not detectable in northern Finnish Lapland. The 3-year mean for total sulphur was 0.20 mg/kg and for pH 4.96 along the sampling line running to the west of Nikel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01186158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Expression of mRNA for vasoactive intestinal peptide in normal human colon and during inflammation (1995)
    Springer
    Molecular and cellular biochemistry 142 (1995), S. 1-7 
    Details
    ISSN: 1573-4919
    Keywords: vasoactive intestinal peptide ; ulcerative colitis ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The availability of colon provides a ready source of human neurons. Among the products of nerve cell bodies, vasoactive intestinal peptide is a neuropeptide that serves as a marker of non-adrenergic, non-cholinergic inhibitory nerves in colon. These nerves have been proposed to be involved in regulation of immune function, secretion, and smooth muscle function. In previous work, we identified decreased tissue levels of vasoactive intestinal peptide in a disorder of chronic colonic mucosal inflammation, ulcerative colitis. We hypothesized that diminished gene expression of vasoactive intestinal peptide could result in decreased tissue levels of this neuropeptide. Sigmoid colon was obtained at surgery from controls (n=6) and patients with ulcerative colitis (n=6). Vasoactive intestinal peptide mRNA was quantified by Northern blot hybridization and tissue levels of vasoactive intestinal peptide were determined by radioimmunoassay. Tissue vasoactive intestinal peptide was decreased only in the mucosalsubmucosal layer of ulcerative colitis (p=.02). There was a single 1.7 kbase vasoactive intestinal peptide transcript identified in both control colon and ulcerative colitis. Normalized vasoactive intestinal peptide mRNA levels were increased by 260% in ulcerative colitis compared to controls (p〈.01). These observations suggest that decreased vasoactive intestinal peptide gene expression or abnormal post-transcriptional processing are not primary defects in this disorder of chronic inflammation. The findings support the alternative hypothesis that axonal degeneration in ulcerative colitis could result in increased expression of neuronal vasoactive intestinal peptide mRNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00928907
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Expression of hepatic calcium-binding protein regucalcin mRNA is elevated by refeeding of fasted rats: Involvement of glucose, insulin and calcium as stimulating factors (1995)
    Springer
    Molecular and cellular biochemistry 142 (1995), S. 35-41 
    Details
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; insulin ; calcium ; gene expression ; rat liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of refeeding on the expression of Ca2+-binding protein regucalcin mRNA in the liver of fasted rats was investigated. When rats were fasted overnight, the hepatic regucalcin mRNA level was reduced about 70% of that in feeding rats. Refeeding produced a remarkable elevation of hepatic regucalcin mRNA level (about 150–170% of fasted rats). Liver regucalcin concentration was appreciably increased by refeeding, although it was not altered by fasting. The oral administration of glucose (2 g/kg body weight) to fasted rats caused a significant increase in hepatic regucalcin mRNA level. Moreover, hepatic regucalcin mRNA level was clearly elevated by a single subcutaneous administration of insulin (10 and 100 U/kg) to fasted rats. The hormonal effect was not further enhanced by the simultaneous administration of calcium chloride (250 mg Ca/kg) to fasted rats, although calcium administration stimulated regucalcin mRNA expression in the liver. The present study suggests that the expression of hepatic regucalcin mRNA stimulated by refeeding is significantly involved in the action of insulin and/or calcium as stimulating factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00928911
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Specific species and tissue differences for the gene expression of calcium-binding protein regucalcin (1995)
    Springer
    Molecular and cellular biochemistry 143 (1995), S. 67-71 
    Details
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; gene distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The existence and expression of gene encoding the Ca2+-binding protein regucalcin in various species and tissues were investigated with Southern and Northern hybridization analyses using regucalcin cDNA (0.9 kb of open reading frame). Genomic Southern hybridization analysis demonstrated that regucalcin gene was widely conserved among higher animals including human, monkey, rat, mouse, dog, bovine, rabbit and chicken. The gene was not found in yeast. The Northern blot analysis of poly (A)+RNAs extracted from the liver of various species showed that regucalcin mRNA was predominantly expressed in rat and mouse, although the expression was also seen in human, bovine and chicken. Furthermore, the enzyme-linked immunoadsorbent assay (ELISA) with rabbit-anti-regucalcin IgG indicated that hepatic regucalcin concentration was most pronounced in rat as compared with that of guinea pig, mouse and chicken. These observations show that the gene expression of regucalcin and its protein synthesis is unique in the liver of rats, suggesting the existence of a specific mechanism in demonstrating regucalcin synthesis from gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00925928
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    17β-Estradiol stimulates the expression of hepatic calcium-binding protein regucalcin mRNA in rats (1995)
    Springer
    Molecular and cellular biochemistry 143 (1995), S. 137-141 
    Details
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; estrogen ; gene expression ; rat liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of nuclear receptor-related hormones on the expression of hepatic calcium-binding protein regucalcin mRNA in rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin cDNA (0.9 kb of open-reading frame). A single subcutaneons administration of 17β-estradiol (0.5, 1.0 and 2.0 mg/kg body weight) in rats induced a remarkable increase of regucalcin mRNA in liver; the level was about 200% of control at 24 h after the administration of 2.0 mg/kg. The increase showed about 350% even at 6 h after the administration. Meanwhile, hepatic regucalcin mRNA level was not appreciably altered by a single subcutaneous administration of thyroxine (T4) (20, 40 and 80 mg/kg) or hydrocortisone (10 and 30 mg/kg) in rats. The present study demonstrates that the expression of hepatic regucalcin mRNA is stimulated by estrogen action in the liver nuclei of rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01816947
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Thyroid hormone inhibits fatty acid synthase gene transcription in chicken liver (1995)
    Springer
    Molecular and cellular biochemistry 144 (1995), S. 105-108 
    Details
    ISSN: 1573-4919
    Keywords: fatty acid synthase ; gene expression ; and thyroid hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of triiodothyronine (T3) on regulation of fatty acid synthase in chicken liver was investigated. In hypothyroid animals, enzyme activity was about one half of that in euthyroid animals. T3 treatment increased the enzyme activity in hypothyroid animals. There is little difference in both the mRNA concentration and the transcription rate between euthyroid and hypothyroid animals. T3 treatment markedly decreased both the mRNA concentration and the transcription rate in euthyroid and hypothyroid animals. These results suggested that T3 maintained the normal level of enzyme expression primarily by stimulating the post-transcriptional step, while the transcription of the gene was inhibited by hyperthyroidism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00944388
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Thiol modulation of TNFα and IL-1 induced MnSOD gene expression and activation of NF-κB (1995)
    Springer
    Molecular and cellular biochemistry 148 (1995), S. 45-57 
    Details
    ISSN: 1573-4919
    Keywords: manganese ; superoxide dismutase ; gene expression ; hyperoxide lung injury ; nuclear factor kappa B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract TNFα and IL-1 each can activate NF-κB and induce gene expression of manganese superoxide dismutase (MnSOD), a mitochondrial matrix enzyme which can provide critical protection against hyperoxic lung injury. The regulation of MnSOD gene expression is not well understood. Since redox status can modulate NF-κB and potential κB site(s) exist in the MnSOD promoter, the effect of thiols (including NAC, DTT and 2-ME) on TNFα and IL-1 induced activation of NF-κB and MnSOD gene expression was investigated. Activation of NF-kB and increased MnSOD expression were potentiated by thiol reducing agents. In contrast, thiol oxidizing or alkylating agents inhibited both NF-κB activation and elevated MnSOD expression in response to TNFα or IL-1. Since protease inhibitors TPCK and TLCK can inhibit NF-κB activation, we also investigated the effect of these compounds on MnSOD expression and NF-κB activation. TPCK and TLCK each inhibited MnSOD gene expression and NF-κB activation. Since the MnSOD promoter also contains anAP-1 binding site, the effect of thiols and thiol modifying agents on AP-1 activation was investigated. Thiols had no consistent effect onAP-1 activation. Likewise, some of the thiol modifying compounds inhibited AP-1 activation by TNFα or IL-1, whereas others did not. Since diverse agents had similar effects on activation of NF-κB and MnSOD gene expression, we have demonstrated that activation of NF-κB and MnSOD gene expression are closely associated and that reduced sulfhydryl groups are required for cytokine mediation of both processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00929502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats: The stimulation by calcium administration (1995)
    Springer
    Molecular and cellular biochemistry 146 (1995), S. 71-77 
    Details
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; rat kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin complementary DNA (0.9 kb of open-reading frame). Regucalcin mRNA was expressed in the kidney cortex, and this expression was clearly increased by a single intraperitoneal administration of calcium chloride solution (5–15 mg Ca/100 g body weight) in rats; this increase was remarkable at 60–120 min after the administration. Thyroparathyroidectomy (TPTX) caused a slight decrease of regucalcin mRNA levels in the kidney cortex. However, the administration of calcium (10 mg/100 g) in TPTX rats produced a clear increase of regucalcin mRNA levels in the kidney cortex. The subcutaneous administration of calcitonin (10–100 MRC mU/100 g) or parathyroid hormone [1–34] (1–10 U/100 g) in TPTX rats which received calcium (10 mg/100 g) administration did not cause an appreciable alteration of regucalcin mRNA levels in the kidney cortex, suggesting that the mRNA expression is not stimulated by calcium-regulating hormones. The administration of trifluoperazine (TFP; 5 mg/100 g), an inhibitor of Ca2+/calmodulin action, completely blocked the expression of regucalcin mRNA stimulated by calcium administration. Now, calcium content in the kidney cortex was significantly elevated by a single intraperitpneal administration of calcium (10 mg/100 g) in rats. The present study clearly demonstrates that the expression of regucalcin mRNA in the kidney cortex is stimulated by calcium administration in rats. This expression may be mediated through Ca2+/calmodulin action in the kidney cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00926884
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    The toxic mixing zone of neutral and acidic river water: Acute aluminium toxicity in brown trout (Salmo trutta L.) (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 341-346 
    Details
    ISSN: 1573-2932
    Keywords: aluminium toxicity ; non-equilibrium chemistry ; pH ; stress ; apoptosis ; necrosis ; trout
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mixing of acid river water containing aluminium (pH 5.1, Al 345 μg.l−1) with neutral water of a lake (pH 7.0, Al 73 μg.l−1) resulted in water (pH 6.4, Al 245 μg.l−1) with a pH (6.4) and Al concentration (245 μg.l−1) expected to have low toxicity to fish on the basis of current Al toxicity models. However, under semi-field conditions the freshly mixed water (a few sec. after mixing) proved to be highly toxic to brown trout. The fish were exposed to the water at different places along a 30 m channel. At the beginning of the channel acid and neutral water were continuously mixed; the mixed water left the channel after 340 sec. The cells of the gills showed a highly increased rate of cell death by apoptosis and necrosis. Intercellular spaces were enlarged, and many leucocytes penetrated in these spaces. Mucus release was stimulated to depletion. Plasma chloride levels were hardly affected. There was a clear gradient in the deleterious effects on the fish along the channel. The fish at the beginning of the channel (about 12 sec. after mixing of the water), were severely affected, whereas the fish kept at the end of the channel (340 sec. after mixing) were only mildly affected. In the natural situation fish will relatively quickly pass through a mixing zone. In our study we therefore focused on the effects on fish after a 60 min exposure to a mixing zone (5 sec after mixing), with subsequent recovery in a region downstream of the confluence and in neutral water with low Al. The recovery in the downstream area (at the end of the channel, i.e. 5 min after mixing) was clearly hampered when compared to the recovery in neutral water with low aluminium. Thus, a short exposure to the toxic mixing zone followed by a stay in water downstream of this zone, as may occur in nature, is detrimental to migrating trout. We conclude that freshly mixed acid and neutral water contain toxic components during the first seconds to minutes after mixing, that can not be explained by current models on aluminium toxicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00476852
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Soil solution chemistry and element budgets of three Scots pine ecosystems along a deposition gradient in north-eastern Germany (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 1197-1202 
    Details
    ISSN: 1573-2932
    Keywords: Scots pine ; Pinus sylvestris ; deposition ; element budget ; soil solution ; soil chemistry ; alkaline dust ; pH ; acidification ; sulfur release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Since 1993 we are studying three Scots pine ecosystems along a deposition gradient in north-eastern Germany (formerly GDR). Dramatic reductions of pollutant emissions are reported for the period since 1989/90. S-deposition is high at the sites Roesa and Taura (25 kg S ha−1yr−1) compared to Neuglobsow. Inputs of basic cations, especially Ca, by alkaline dust immissions decrease in the order Roesa 〉 Taura 〉 Neuglobsow. The soil solution data show high concentrations of Ca and SO4 at Roesa decreasing drastically along the deposition gradient. The elevated pH values reflect the impact of alkaline dust deposition particularly in the organic surface layer at Roesa. The site Taura received less base cation deposition and is marked by the lowest pH values throughout the soil profile combined with increased Al concentrations in the solution of the mineral soil. Thus, the composition of the soil solutions clearly reflects the different deposition regimes of the past. The element budgets show that large amounts of base cations, sulfur, and, at Taura, also aluminum are actually released from the soils that were previously stored.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00477144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Deposition around a coal-fired power station during a wintertime precipitation event (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 2125-2130 
    Details
    ISSN: 1573-2932
    Keywords: wet deposition ; sulphate ; pH ; snowfall ; Doppler weather radar ; short-range deposition modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The contribution to local wet deposition of emissions from a coal-fired power station at Inkoo on the south coast of Finland has been investigated during a wintertime precipitation event. Making use of intensive radiosonde and weather radar observations of meteorological factors, concentrations of sulphur in deposition due to plume washout were predicted by a short-range deposition model. The model used the scavenging coefficient to parametrize the wet removal of pollutants, and it took into account the wind drift of falling precipitation particles within the plume. The model predictions were then compared with the chemical analysis results from snowfall samples collected within 10 km of the power station during the experiment. The experiment was performed ahead of a deeply-occluded front during a period with strong advection of long-range transported pollutants. No reliable sign of the influence of the power station on the sulphate deposition could be identified. On the other hand, the deviations of acidity from the mean pH-value of 4.1 were concentrated in one sector near the expected area of deposited plume pollutants. If local emissions were responsible for these deviations, the explanation may lie in a slightly incorrectly estimated plume direction or the effects of alkaline fly ash. Nevertheless, definite conclusions cannot be drawn, because only a few collectors happened to be sited in the modelled sector of plume washout and none in its maximum area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01186148
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Suppressed expression of calcium-binding protein regucalcin mRNA in the renal cortex of rats with chemically induced kidney damage (1995)
    Springer
    Molecular and cellular biochemistry 151 (1995), S. 55-60 
    Details
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium ; gene expression ; kidney damage ; rat kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The alteration of Ca2+-binding protein regucalcin mRNA expression in the kidney cortex of rats administered cisplatin and cephaloridine, which can induce kidney damage, was investigated. Cisplatin (0.25, 0.5 and 1.0 mg/100 g body weight) or cephaloridine (25, 50 and 100 mg/100 g) was intraperitoneally administered in rats, and 1, 2 and 3 days later they were sacrificed. The alteration in serum findings after the administration of cisplatin (1.0 mg/100 g) or cephaloridine (50 and 100 mg/100 g) demonstrated chemically induced kidney damage; blood urea nitrogen (BUN) concentration increased markedly and serum inorganic phosphorus or calcium concentration decreased significantly. Moreover, the administration of cisplatin (1.0 mg/100 g) or cephaloridine (100 mg/100 g) caused a remarkable increase of calcium content in the kidney cortex of rats, indicating kidney damage. The expression of regucalcin mRNA in the kidney cortex was markedly reduced by the administration of cisplatin or cephaloridine in rats, when the mRNA levels were analyzed by Northern blotting using rat liver regucalcin cDNA (0.9 kb). The mRNA decreases were seen with the used lowest dose of cisplatin or cephaloridine. The present study clearly demonstrates that the mRNA expression of Ca2+-binding protein regucalcin in the kidney cortex of rats is decreased by chemically induced kidney damage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01076896
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Molecular remodelling in hypertrophied hearts from polyomavirus large T-antigen transgenic mice (1995)
    Springer
    Molecular and cellular biochemistry 152 (1995), S. 131-141 
    Details
    ISSN: 1573-4919
    Keywords: gene expression ; mRNA ; proto-oncogenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Polyomavirus large T-antigen transgenic mice develop cardiac hypertrophy characterized by an increase in atrial natriuretic factor and β-myosin heavy chain isoform expression. The aim of this study was to examine changes in proto-oncogene expression in hypertrophied hearts from the transgenic mice. Expression of early growth response-1 (Egr-1) mRNA was detected in hearts from all 15 transgenic mice, but was not detectable in 13 control mice. Reverse transcriptase-polymerase chain reaction experiments usingEgr-1-specific primers confirmed the increase inEgr-1 mRNA in enlarged hearts from the transgenic mice. Expression of c-jun,junD and Ha-ras mRNAs was increased in the transgenic hearts 3, 17 and 2.8-fold, respectively. Western blots showed an increase in c-myc, c-jun and ras protein in hypertrophied transgenic hearts. Immunofluorescence analyses confirmed an increase in Egr-1 and c-jun protein in transgenic cardiomyocytes. Proliferating cell nuclear antigen, Ki-ras and HSP 90 mRNAs were decreased 22, 2.7 and 3-fold, respectively in the transgenic hearts. Not altered in most hypertrophied hearts was expression of c-fos, junB, p53, c-neu, c-myc, HSP70, HSP27, TGF-β or IGF-1 mRNAs. Proto-oncogene and growth factor gene expression in hypertrophy induced by PVLT expression is modulated, with some proto-oncogenes increased and others decreased in expression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01076075
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Structural organization and differential expression of carrot β-fructofuranosidase genes: identification of a gene coding for a flower bud-specific isozyme (1995)
    Springer
    Plant molecular biology 28 (1995), S. 189-194 
    Details
    ISSN: 1573-5028
    Keywords: β-fructofuranosidase ; invertase ; gene expression ; gene structure ; flower buds ; Daucus carota
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three genomic clones (Inv *Dc1, Inv *Dc2 and Inv *Dc3) were isolated by using the cDNA for carrot cell wall β-fructofuranosidase as a probe. The expression patterns of the three genes differed markedly. High levels of Inv *Dc1 transcripts were found in leaves and roots of young carrot, whereas in plants with developing tap roots no transcripts were detected. A high level of mRNA of Inv *Dc1 was also present in suspension-cultured cells. In developing reproductive organs, only low levels of transcripts of Inv *Dc1 were found in flower buds and flowers and none at later stages of development. In contrast, Inv *Dc2 and Inv *Dc3 were not expressed in vegetative plant organs. Invb1 *Dc1 was exclusively and strongly expressed in flower buds, and Inv *Dc3 at a very low level in suspension-cultured cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042049
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    High levels of ripening-specific reporter gene expression directed by tomato fruit polygalacturonase gene-flanking regions (1995)
    Springer
    Plant molecular biology 28 (1995), S. 423-435 
    Details
    ISSN: 1573-5028
    Keywords: fruit ; gene expression ; promoter ; ripening ; tomato ; transgenic plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The 1.4 kb 5′ polygalacturonase (PG) gene-flanking region has previously been demonstrated to direct ripening-specific chloramphenicol acetyl transferase (CAT) expression in transgenic tomato plants. The steady state level of CAT mRNA in these plants was estimated to be less than 1% of the endogenous PG mRNA. Further constructs containing larger PG gene-flanking regions were generated and tested for their ability to direct higher levels of reporter gene expression. A 4.8 kb 5′-flanking region greatly increased levels of ripening-specific reporter gene activity, while a 1.8 kb 3′ region was only shown to have a positive regulatory role in the presence of the extended 5′ region. Transgenic plants containing the CAT gene flanked by both of these regions showed the same temporal pattern of accumulation of CAT and PG mRNA, and steady-state levels of the transgene mRNA were equivalent to 60% of the endogenous PG mRNA on a per gene basis. The proximal 150 bp of the PG promoter gave no detectable CAT activity. However, the distal 3.4 kb of the 4.8 kb 5′ PG promoter was shown to confer high levels of ripening-specific gene expression when placed in either orientation upstream of the 150 bp minimal promoter. The DNA sequence of the 3.4 kb region revealed a 400 bp imperfect reverse repeat, and sequences which showed similarity to functionally significant sequences from the ripening-related, ethylene-regulated tomato E8 and E4 gene promoters. The possible roles of the flanking regions in regulating PG gene expression are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020391
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Organization, inheritance and expression of acetohydroxyacid synthase genes in the cotton allotetraploid Gossypium hirsutum (1995)
    Springer
    Plant molecular biology 28 (1995), S. 837-846 
    Details
    ISSN: 1573-5028
    Keywords: acetohydroxyacid synthase ; gene organization ; gene expression ; herbicide resistance ; cotton ; Gossypium hirsutum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The acetohydroxyacid synthase (AHAS) gene family of the cotton AD allotetraploid Gossypium hirsutum has been cloned and characterized. We have identified six different AHAS genes from an analysis of genomic clones and Southern blots of genomic DNA. Four of the six genes are organized as tandem pairs, in which the genes are separated by only 2–3 kb. Conservation of restriction fragment length polymorphisms between G. hirsutum and A-genome and D-genome-containing diploid cottons was sufficient to assign the single genes in clones A5 and A19 to the A and D subgenomes, respectively. Each diploid genome has one tandem pair, but in these cases we could not make specific subgenomic assignments. DNA and deduced amino acid sequences were determined for the A5 and A19 genes, and an AHAS cDNA clone isolated from a leaflibrary. The sequence of the A19 gene matches that of the cDNA clone, while the A5 gene is 97.8% similar. The four genes comprising the tandem pairs are much less similar to the cDNA clone. The deduced amino acid sequences of the mature polypeptides encoded by the A5 and A19 genes are collinear with the housekeeping forms of AHAS from Arabidopsis thaliana, Nicotiana tabacum and Brassica napus. The constitutive expression of A5 and A19 was confirmed with RNase protection assays and northern blots. We conclude that these genes encode the main house-keeping froms of AHAS in G. hirsutum. Among the four AHAS genes comprising the two tandem pairs, at least two are functional. These genes exhibit either low-level constitutive expression (one or both of the ‘downstream’ genes of each pair), or highly specific expression in reproductive tissue (one or both of the ‘upstream’ genes of each pair). The AHAS gene family of G. hirsutum is more complex than that of other plants so far examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042069
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Isolation of cDNA clones of genes with altered expression levels in phosphate-starved Brassica nigra suspension cells (1995)
    Springer
    Plant molecular biology 28 (1995), S. 859-870 
    Details
    ISSN: 1573-5028
    Keywords: Brassica ; phosphate starvation ; gene expression ; β-glucosidase ; mineral nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Differential gene expression at the transcriptional level was examined as an initial step in the investigation of the Pi starvation response of Brassica nigra suspension cells. Total RNA was extracted from 7-day old cells grown in media containing either no Pi, 1.25 mM or 10 mM Pi., In vitro translation was carried out using their respective poly(A)+ RNA isolates and the resultant polypeptides were separated on a high-resolution SDS-PAGE gel. Scanning densitometry identified four polypeptides (ca. 31.7, 32.3, 52.5 and 64.8 kDa) present only in the Pi-starved samples. Screening by differential hybridization was performed on a cDNA library constructed from mRNA isolated from Pi-starved cells. Probes prepared from mRNA from Pi-deficient and Pi-sufficient cells identified a number of clones representing mRNA species that were preferentially transcribed under Pi deficiency. These phosphate starvation-responsive (psr) clones were placed into eleven groups as determined by cross-hybridization. Northern blots showed that the corresponding genes are inducible in both mild and severe Pi starvation conditions. Preliminary sequencing identified one of the clones as being homologous to β-glucosidases from several plant species. The possible role of β-glucosidase during Pi starvation and the identities of the other psr genes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042071
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Molecular cloning of two tandemly arranged peroxidase genes from Populus kitakamiensis and their differential regulation in the stem (1995)
    Springer
    Plant molecular biology 28 (1995), S. 677-689 
    Details
    ISSN: 1573-5028
    Keywords: linked gene ; gene expression ; peroxidase ; Populus kitakamiensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A genomic library was prepared from Populus kitakamiensis and screened with the cDNA for an anionic peroxidase from P. kitakamiensis. One genomic clone was isolated that contained two tandemly oriented genes for anionic peroxidases, prxA3a and prxA4a. Both genes consisted of four exons and three introns; the introns had consensus nucleotides, namely, GT and AG, at their 5′ and 3′ ends, respectively. The prxA3a and prxA4a genes encoded 347 and 343 amino acid residues, respectively, including putative signal sequences at the amino-termini. Putative promoters and polyadenylation signals were found in the flanking regions of both genes. The sequence of the coding region of prxA3a was completely identical to that of the cDNA clone pA3, whereas the sequence of the coding region of prxA4a was only 73% identical to that of the cDNA clone pA3. Northern blot analysis showed that the patterns of expression of the mRNAs that corresponded to prxA3a and prxA4a differed in stems of P. kitakamiensis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00021193
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Gerbera hybrida (Asteraceae) imposes regulation at several anatomical levels during inflorescence development on the gene for dihydroflavonol-4-reductase (1995)
    Springer
    Plant molecular biology 28 (1995), S. 935-941 
    Details
    ISSN: 1573-5028
    Keywords: anthocyanin ; Compositae ; corolla ; dfr ; flower development ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the ornamental cut flower plant Gerbera hybrida the spatial distribution of regulatory molecules characteristic of differentiation of the composite inflorescence is visualized as the various patterns of anthocyanin pigmentation of different varieties. In order to identify genes that the plant can regulate according to these anatomical patterns, we have analysed gene expression affecting two enzymatic steps, chalcone synthase (CHS) and dihydroflavonol-4-reductase (DFR), in five gerbera varieties with spatially restricted anthocyanin pigmentation patterns. The dfr expression profiles vary at the levels of floral organ, flower type and region within corolla during inflorescence development according to the anthocyanin pigmentation of the cultivars. In contrast, chs expression, although regulated in a tissue-specific manner during inflorescence development, varies only occasionally. The variation in the dfr expression profiles between the varieties reveals spatially specific gene regulation that senses the differentiation events characteristic of the composite inflorescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042077
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Cytoplasmic HSP70 homologues of pea: differential expression in vegetative and embryonic organs (1995)
    Springer
    Plant molecular biology 27 (1995), S. 441-456 
    Details
    ISSN: 1573-5028
    Keywords: HSP70 ; HSC70 ; seed development ; imbibition ; chaperone ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eukaryotes express several cytoplasmic HSP70 genes, and their encoded proteins participate in diverse cellular processes. Three cDNAs encoding highly expressed cytoplasmic HSP70 homologues from Pisum sativum were cloned and characterized. They were designated PsHSP71.2, PsHSC71.0, and PsHSP70b. These HSP70 genes have different expression profiles in leaves: PsHSP71.2 is observed only in response to heat stress, PsHSC71.0 is present constitutively, and PsHSP70b is weakly constitutively expressed, but induced strongly in response to heat stress. In addition to being heat induced, the PsHSP71.2 mRNA is also expressed in zygotic, but not maternal organs of developing pea seeds, while PsHSC71.0 and PsHSP70b mRNAs are present in maternal and zygotic organs throughout seed development. Immunoblot analysis of parallel protein samples detects a 70 kDa polypeptide in all samples, and a 72 kDa polypeptide that corresponds to the PsHSP71.2 gene product is observed in cotyledons beginning at mid-maturation and in axes beginning between late maturation and desiccation. This polypeptide is not detected in the seed coat. The 72 kDa polypeptide remains abundant in both cotyledons and axes through germination, but declines substantially between 48 and 72 h after the onset of imbibition. Differential control of HSP70 expression during heat stress, seed maturation, and germination is consistent with the hypothesis that there are functional distinctions between cytoplasmic HSP70s.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    The isocitrate lyase gene of cucumber: Isolation, characterisation and expression in cotyledons following seed germination (1995)
    Springer
    Plant molecular biology 27 (1995), S. 487-497 
    Details
    ISSN: 1573-5028
    Keywords: Cucumis sativus ; gene expression ; glyoxylate cycle ; glyoxysome ; isocitrate lyase ; seed germination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cucumber (Cucumis sativus L.) genome contains only a single gene encoding the glyoxylate cycle enzyme isocitrate lyase (ICL). The cucumber icl gene has been isolated and sequenced, revealing only two small introns. The predicted amino acid sequence is more than 85% identical to ICL from other higher plants, and contains the C-terminal tripeptide Ser-Arg-Met which resembles a peroxisomal targeting sequence. The icl gene is coordinately expressed with the malate synthase (ms) gene after seed germination in both the light and the dark, suggesting that these genes may contain similar DNA elements regulating transcription. The start of transcription of the icl gene was determined and the DNA sequences upstream compared with the region of the ms gene promoter known to regulate transcription. This comparison revealed a highly conserved DNA sequence at similar positions in each gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Isolation of a full-length mitotic cyclin cDNA clone CycIIIMs from Medicago sativa: Chromosomal mapping and expression (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1059-1070 
    Details
    ISSN: 1573-5028
    Keywords: Alfalfa ; cell division cycle ; chromosomal location ; cyclin ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyclins in association with the protein kinase p34cdc2and related cyclin-dependent protein kinases (cdks) are key regulatory elements in controlling the cell division cycle. Here, we describe the identification and characterization of a full-length cDNA clone of alfalfa mitotic cyclin, termed CycIIIMs. Computer analysis of known plant cyclin gene sequences revealed that this cyclin belongs to the same structural group as the other known partial alfalfa cyclin sequences. Genetic segregation analysis based on DNA-DNA hybridization data showed that the CycIIIMs gene(s) locates in a single chromosomal region on linkage group 5 of the alfalfa genetic map between RFLP markers UO89A and CG13. The assignment of this cyclin to the mitotic cyclin class was based on its cDNA-derived sequence and its differential expression during G2/M cell cycle phase transition of a partially synchronized alfalfa cell culture. Sequence analysis indicated common motifs with both the A- and B-types of mitotic cyclins similarly to the newly described B3-type of animal cyclins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020880
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Molecular cloning and expression analysis of peroxidase genes from wheat (1995)
    Springer
    Plant molecular biology 29 (1995), S. 647-662 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; peroxidase ; powdery mildew ; splicing ; Triticum aestivum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A PCR-based screening approach was used to isolate genomic clones from wheat encoding peroxidase isozymes. Three complete genes (pox1, pox2 and pox4) and one truncated gene (pox3) were characterized. The nucleotide sequences predicted mature proteins of 31 kDa, in which all the highly conserved motifs of secreted plant peroxidases were preserved. The coding regions showed 73–83% DNA sequence identity, with the highest level of similarity noted for the tandemly oriented pox2 and pox3. Expression of respective pox genes in various tissues of wheat was assessed by the RT-PCR technique, which showed that all four genes are active. The primary pox1 mRNA was spliced to remove three introns, whereas processing of the other pox transcripts involved only two intervening sequences. Splicing occurred at consensus GU/AG splice sites except for the first introns of pox1, pox2 and pox4 transcripts, where processing took place at unusual GC donor sites. The RNA analysis suggested that the pox1, pox2 and pox4 genes are predominantly expressed in roots. Lower levels of expression were found for pox4 and pox3 in leaves. Infection of wheat by the powdery mildew fungus selectively induced expression of pox2 in leaves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041156
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    A non-photosynthetic ferredoxin gene is induced by ethylene in Citrus organs (1995)
    Springer
    Plant molecular biology 29 (1995), S. 1211-1221 
    Details
    ISSN: 1573-5028
    Keywords: ferredoxin ; Citrus ; ethylene ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sequence and expression of mRNA homologous to a cDNA encoding a non-photosynthetic ferredoxin (Fd1) from Citrus fruit was investigated. The non-photosynthetic nature of this ferredoxin was deduced from: (1) amino acid sequence alignments showing better scores with non-photosynthetic than with photosynthetic ferredoxins, (2) higher expression in tissues containing plastids other than chloroplast such as petals, young fruits, roots and peel of fully coloured fruits, and (3) the absence of light-dark regulation characteristic of photosynthetic ferredoxins. In a phylogenetic tree constructed with higher-plant ferredoxins, Citrus fruit ferredoxin clustered together with root ferredoxins and separated from the photosynthetic ferredoxins. Non photosynthetic (root and fruit) ferredoxins, but not the photosynthetic ferredoxins, have their closest homologs in cyanobacteria. Analysis of ferredoxin genomic organization suggested that non-photosynthetic ferredoxins exist in Citrus as a small gene family. Expression of Fd1 is developmentally regulated during flower opening and fruit maturation, both processes may be mediated by ethylene in Citrus. Exogenous ethylene application also induced the expression of Fd1 both in flavedo and leaves. The induction of non-photosynthetic ferredoxins could be related with the demand for reducing power in non-green, but biosynthetically active, tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020463
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    The effect of matrix attached regions (MAR) and specialized chromatin structure (SCS) on the expression of gene constructs in cultured cells and in transgenic mice (1995)
    Springer
    Molecular biology reports 22 (1995), S. 37-46 
    Details
    ISSN: 1573-4978
    Keywords: MAR ; SCS ; insulation ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The flanking sequences of several genes have been shown to direct a position independent expression of transgenes. Attempts to completely identify the insulating sequences have failed so far. Some of these sequences contain a matrix attached region (MAR) located in the flanking part of the genes. This article will show that the MARs in cultured cells located in the 3' OH region of the human apolipoprotein B100 (Apo B100) and within the SV40 genome were unable to stimulate and insulate transgene expression directed by the promoters from a rabbit whey acidic protein (WAP) gene or from human cytomegalovirus (hCMV) early genes. In transgenic mice, the MAR from the Apo B100 and SV40 genes did not enhance the expression of a transgene containing the rabbit whey acid protein (WAP) promotor, the late gene SV40 intron (VP1 intron), the bovine growth hormone (bGH) cDNA and the SV40 late gene terminator. This construct was even toxic for embryos. Similarly, the specialized chromatin structure (SCS) from the Drosophila 87A7 HSP70 gene reduced chloramphenicol acetyl transferase (CAT) activity when added between a cytomegalovirus (CMV) enhancer and a Herpes simplex thymidine kinase (TK) gene promoter. This inhibitory action was almost complete when a second SCS sequence was added before the CMV enhancer. Sequences from the firefly luciferase and from the human gene cathepsin D cDNA used as control unexpectedly showed a similar inhibitory effect when added to the CMVTKCAT construct instead of SCS. When added before the CMV enhancer and after the transcription terminator in the CMVTKCAT construct, the SCS sequence was unable to insulate the integrated gene as seen by the fact that the level of CAT in cell extracts were by no means correlated with the number of copies in individual clones. From these data, it is concluded that i) a MAR containing the canonical AT rich sequences does not amplify the expression of all gene constructs ii) AT rich MAR sequences do not have per se an insulating effect iii) Drosophila SCS from the 87A7 HSP70 gene has no insulating effect in all gene constructs (at least in mammalian cells) iv) and the addition of a DNA fragment between an enhancer and a promoter in a gene construct cannot be used as a reliable test to evaluate its insulating property.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00996303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    A homologue of the MAP/ERK family of protein kinase genes is expressed in vegetative and in female reproductive organs of Petunia hybrida (1995)
    Springer
    Plant molecular biology 27 (1995), S. 339-350 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; embryo sac ; ovule ; Petunia hybrida ; protein ; kinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mitogen activated protein (MAP) kinase pathway of eukaryotes is stimulated by many growth factors and is required for the integration of multiple cellular signals. In order to study the function of MAP kinases during plant ovule development we have synthesized a Petunia hybrida ovule-specific cDNA library and screened for MAP protein kinase-related sequences using a DNA probe obtained by PCR. A full-length cDNA clone was identified (PMEK for Petunia hybrida MAP/ERK-related protein kinase) and shown to encode a protein related to the family of MAP/ERK protein kinases. Southern blot analysis showed that PMEK is a member of a small multigene family in P. hybrida. The cDNA codes for a protein (PMEK1) of 44.4 kDa with an overall sequence identity of 44% to the products of the mammalian ERK/MAP kinase gene, and the budding yeast KSS1 and FUS3 genes. PMEK1 displays 96 and 80% identity respectively with the tobacco NTF3 and Arabidopsis ATMPK1 kinases, and only 50% to the more distantly related plant MAP kinase MsERK1 from alfalfa. The two phosphorylation sites found in the loop between subdomain VII and VIII in all the other MAP kinases are also present in PMEK1. RNA gel blot and RT-PCR analyses demonstrated that PMEK1 is expressed in vegetative organs and preferentially accumulated in female reproductive organs of P. hybrida. In situ hybridization experiments showed that in the reproductive organs PMEK1 is expressed only in the ovary and not in the stamen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020188
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Isolation and expression analysis of cDNA clones encoding a small and a large subunit of ADP-glucose pyrophosphorylase from sugar beet (1995)
    Springer
    Plant molecular biology 27 (1995), S. 191-197 
    Details
    ISSN: 1573-5028
    Keywords: ADP-glucose pyrophosphorylase (small and large subunit) ; DNA sequence ; gene expression ; starch synthesis ; sugar beet (Beta vulgaris L.)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cDNA cloning of a small and a large subunit of ADP-glucose pyrophosphorylase (AGPase) from sugar beet is reported. The deduced amino acid sequences are highly homologous to previously identified AGPase polypeptides from other plant species. Both subunits are encoded by low copy genes. When RNA gel blot experiments were performed, strongest expression was detected in sink and source leaves of greenhouse-grown sugar beet plants. A lower expression was found in other tissues tested, i.e. in the hypocotyl, the tap root and roots. In these tissues, slightly higher transcript levels were found for the small subunit gene than for the large subunit gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019190
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Expression of the betaine aldehyde dehydrogenase gene in barley in response to osmotic stress and abscisic acid (1995)
    Springer
    Plant molecular biology 27 (1995), S. 307-315 
    Details
    ISSN: 1573-5028
    Keywords: glycine betaine ; betaine aldehyde dehydrogenase ; osmotic stress ; gene expression ; plant hormone ; abscisic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When subjected to salt stress or drought, some vascular plants such as barley respond with an increased accumulation of the osmoprotectant glycine betaine (betaine), being the last step of betaine synthesis catalyzed by betaine aldehyde dehydrogenase (BADH). We report here cloning and characterization of BADH cDNA from barley, a monocot, and the expression pattern of a BADH transcript. An open reading frame of 1515 bp encoded a protein which showed high homology to BADH enzymes present in other plants (spinach and sugar-beet) and in Escherichia coli. Transgenic tobacco plants harboring the clone expressed high levels of both BADH protein and its enzymatic activity. Northern blot analyses indicated that BADH mRNA levels increased almost 8-fold and 2-fold, respectively, in leaves and roots of barley plants grown in high-salt conditions, and that these levels decreased upon release of the stress, whereas they did not decrease under continuous salt stress. BADH transcripts also accumulate in response to water stress or drought, indicating a common response of the plant to osmotic changes that affect its water status. The addition of abscisic acid (ABA) to plants during growth also increased the levels of BADH transcripts dramatically, although the response was delayed when compared to that found for salt-stressed plants. Removal of plant roots before transferring the plants to high-salt conditions reduced only slightly the accumulation of BADH transcripts in the leaves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020185
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Loss of chloroplast transcripts for proteins associated with photosystem II: an early event during heat-bleaching in Euglena gracilis (1995)
    Springer
    Plant molecular biology 27 (1995), S. 317-325 
    Details
    ISSN: 1573-5028
    Keywords: chloroplasts ; gene expression ; heat bleaching ; photosynthesis ; transcription
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A shift in the ratio of chlorophyll (Chl) a and Chl b is an early indicator of heat bleaching in Euglena gracilis. This observation prompted us to consider whether or not changes in steady-state levels of chloroplast transcripts and in transcriptional activity could limit the synthesis of Chl a-binding proteins in bleaching plastids. We found that the mature transcripts for CP47 and CP43, the Chl a-binding apoproteins of the proximal antenna of photosystem II, decline sharply very early during bleaching. Our study also shows that transcription of psbB and psbC, the chloroplast genes encoding CP47 and CP43, remains essentially unchanged during the same interval. We conclude that posttranscriptional events, such as mRNA stability, could play a major role in initiating an irreversible loss of chloroplast function in Euglena at a moderately elevated temperature. Lack of these transcripts would eventually impair the assembly of photosystem II in thylakoids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020186
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Differential expression of two barley SNF1-related protein kinase genes (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1235-1240 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; gene family ; higher plants ; Hordeum vulgare ; metabolic regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have amplified and cloned DNA sequences derived from a gene encoding a SNF1 (sucrose-non-fermenting 1)-related protein kinase which differs from that previously reported from barley. Northern blot and polymerase chain reaction (PCR) analysis of RNA populations, using specific probes and oligonucleotide primers, indicated that the two SNF1-related genes are differentially regulated. One is expressed in all tissues, whereas the other is expressed at high levels in the seed endosperm and aleurone, but at levels undetectable by northern blot analysis in other tissues. Comparisons with other plant SNF1-related protein kinase genes suggest that the form which is expressed at greatly enhanced levels in the seed is less similar to the other plant homologues which have been reported and may be unique to cereals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020898
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Evidence for some common signal transduction events for opposite regulation of nitrate reductase and phytochrome-I gene expression by light (1995)
    Springer
    Plant molecular biology 29 (1995), S. 25-35 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; light regulation ; nitrate reductase ; phytochrome ; signal transduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have explored the possible involvement of the phosphoinositide (PI) cycle and protein kinase C (PKC) in the phytochrome (Pfr)-mediated light signal transduction pathway using nitrate reductase (NR) and phytochrome-I (PhyI) genes as model systems. We have shown earlier that phorbol myristate acetate (PMA) completely replaces the red light effect in stimulating nitrate reductase activity and transcript levels in maize. In this paper, we present detailed evidence to show that PMA mimics the red light effect and follows similar kinetics to enhance NR steady-state transcript accumulation in a nitrate-dependent manner. We also show that PMA inhibits phyI steady-state transcript accumulation in a manner similar to red light, indicating that a PKC-type enzyme(s) may be involved in mediating the light effect in both cases. Serotonin or 5-hydroxytryptamine (5-HT), a stimulator of PI turnover, was also found to mimic the red light effect in enhancing NR transcript levels and inhibiting phyI transcript accumulation, indicating the role of the PI cycle in generating second messengers for regulating the two genes. These results indicate that phytochrome-mediated light regulation of NR and phyI gene expression may involve certain common steps in the signal transduction pathway such as the PI cycle and protein phosphorylation by a PKC-type enzyme.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019116
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Promoter analysis of the auxin-regulated tobacco glutathione S-transferase genes Nt103-1 and Nt103-35 (1995)
    Springer
    Plant molecular biology 29 (1995), S. 413-429 
    Details
    ISSN: 1573-5028
    Keywords: auxin ; DNA binding factor ; gene expression ; glutathione S-transferase ; Nicotiana tabacum ; signal transduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have analysed the promoter regions of two closely related auxin-regulated glutathione S-transferase genes. All active deletion constructs tested showed expression of the reporter gene β-glucuronidase (gusA) in root tips of young seedlings and newly developing lateral roots. Auxin treatment greatly enhanced the level of expression. The Nt103-1 promoter region −370/−276 was found to be necessary, at least as a quantitative element to confer auxin-responsiveness to a reporter gene, and sequences responsible for the auxin-responsiveness must be located downstream of −370. The region −651/−370 contains sequence information necessary for uninduced expression. The Nt103-35 promoter manifested its auxin-responsiveness within the −504/−310 region. Electrophoretic mobility shift analysis, using nuclear extracts from tobacco leaves and suspension cells, identified a factor binding to a sequence (ap103, TGAGTCT) at position −560 of the Nt103-1 promoter, which shows homology to the mammalian AP-1 site. A second factor was found to bind a sequence (as103, ATAGCTAAGTGCTTACG) with homology to the CaMV 35S promoter as-1 element. The as103 element is present in both promoters and positioned around −360, so within the region determined to be indispensable for the response to auxin. A third factor was found binding to the −276/−190 region of both promoters. Combined, these data point to the relevance of a 90 bp region for auxin-induced activity of both tobacco genes. The ASF-1 like factor binding to the as103 element within this region might be involved in mediating the auxin response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020974
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    A role for glutamate decarboxylase during tomato ripening: the characterisation of a cDNA encoding a putative glutamate decarboxylase with a calmodulin-binding site (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1143-1151 
    Details
    ISSN: 1573-5028
    Keywords: differential screening ; gene expression ; Lycopersicon esculentum ; rin ; ripening inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A tomato fruit cDNA library was differentially screened to identify mRNAs present at higher levels in fruit of the tomato ripening mutant rin (ripening inhibitor). Complete sequencing of a unique clone ERT D1 revealed an open reading frame with homology to several glutamate decarboxylases. The deduced polypeptide sequence has 80% overall amino acid sequence similarity to a Petunia hybrida glutamate decarboxylase (petGAD) which carries a calmodulin-binding site at its carboxyl terminus and ERT D1 appears to have a similar domain. ERT D1 mRNA levels peaked at the first visible sign of fruit colour change during normal tomato ripening and then declined, whereas in fruit of the ripening impaired mutant, rin, accumulation of this mRNA continued until at least 14 days after the onset of ripening. This mRNA was present at much lower levels in other tissues, such as leaves, roots and stem, and was not increased by wounding. Possible roles for GAD, and its product γ-aminobutyric acid (GABA) in fruit, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020887
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Isolation and characterisation of a melon cDNA clone encoding phytoene synthase (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1153-1162 
    Details
    ISSN: 1573-5028
    Keywords: carotenoids ; cleavage site ; gene expression ; melon ; phytoene synthase ; ripening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA clone (MEL5), encoding a protein homologous to phytoene synthase (PSY), has been isolated from a climacteric melon fruit cDNA library, using the tomato cDNA clone TOM5 [34] as a heterologous probe. MEL5 hybridised to a transcript of 1.65 kb which suggested that the 1.36 kb clone, isolated originally, was not full-length. The missing 5′ end was isolated by a reverse transcriptase-polymerase chain reaction (RT-PCR)-based method. This enabled the full sequence of the protein to be deduced and the cleavage site of the transit peptide for chromoplast import to be predicted. Northern analysis of RNA extracted from fruit samples of different ripening stages as well as from roots, leaves and flower petals was used to examine the expression pattern of the corresponding mRNA. The transcript corresponding to MEL5 is present at low quantities in unripe (green) fruit, reaches its highest levels when the fruit turns from green to orange and persists at lower levels during later ripening stages. A similar transcript was also detected in flower petals and in trace amounts in leaves and roots. Genomic Southern analysis indicates that the clone is homologous to a low-copy-number gene family. Sequence analysis showed a high degree of conservation among plant PSYs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020888
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    An unusual Group 2 LEA gene family in citrus responsive to low temperature (1995)
    Springer
    Plant molecular biology 29 (1995), S. 11-23 
    Details
    ISSN: 1573-5028
    Keywords: drought ; flooding ; freezing tolerance ; gene expression ; salt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six cDNAs representing unique cold-induced sequences have been cloned from the hardy citrus relative Poncirus trifoliata. Among these, pBCORc115 and pBCORc119 were found to belong to the same gene family. Sequencing data indicated that pBCORc115 and pBCORc119 each contained an open reading frame, coding for a 19.8 kDa protein (COR19) and a smaller 11.4 kDa protein (COR11) respectively. Inspection of the deduced amino acid sequences revealed three large repeats in COR19, but only one was present in the COR11. Two elements: a Q-clustered tract and a K-rich motif were identified in each repeat. The K-rich motifs were similar to those of cotton D-11 and Group 2 LEA proteins. A Serine-cluster, a common feature in many Group 2 LEA-like proteins, was also found in these proteins, but it was in an unusual position at the carboxy-terminus. A bipartite motif of basic residues, similar to known nuclear targeting sequences, was also present in COR19 and COR11, suggesting that members of this protein family may have a nuclear targeting function. The expression of COR19 mRNA in response to cold acclimation, drought, flooding, and salinization was examined. COR19 expression in leaf tissue was induced in response to cold acclimation, but repressed during drought and flooding stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Abundance and half-life of the distinct oat phytochrome A3 and A4 mRNAs (1995)
    Springer
    Plant molecular biology 29 (1995), S. 367-377 
    Details
    ISSN: 1573-5028
    Keywords: Avena sativa ; gene expression ; PHYA ; light regulation ; mRNA degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gene-preferential oligonucleotide probes were used to determined the relative abundance and half-lives of distinct oat phytochrome A (PHYA) mRNAs. Oat PHYA mRNAs are highly conserved in the 5′-untranslated region and the coding region, but the 3′-untranslated region has an overall lower sequence conservation and was the source of gene-preferential probes. PHYA3 mRNA was estimated to be ca. 61% of the oat PHYA mRNA pool present in poly(A)+ RNA from dark-grown seedlings. The half-lives for PHYA3 and PHYA4 mRNAs were both estimated to be ca. 30 min, and a similar short half-life was estimated for the average PHYA mRNA. Sequence comparisons of PHYA mRNAs from four grass species identified conserved sequences within the 5′- and 3′-untranslated regions that might be important for PHYA mRNA degradation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00043659
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Expression of arabidopsis cytosolic ascorbate peroxidase gene in response to ozone or sulfur dioxide (1995)
    Springer
    Plant molecular biology 29 (1995), S. 479-489 
    Details
    ISSN: 1573-5028
    Keywords: Ascorbate peroxidase ; Arabidopsis thaliana ; gene expression ; guaiacol peroxidase ; ozone ; sulfur dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of ozone or sulfur dioxide on antioxidant enzymes were investigated in Arabidopsis thaliana. Plants were fumigated with 0.1–0.15 ppm ozone or sulfur dioxide up to about 1 week in an environment-controlled chamber. Both pollutants increased the activities of ascorbate peroxidase and guaiacol per-oxidase in leaves, but had little effect on the activities of superoxide dismutase, catalase, monodehydroascorbate reductase, dehydroascorbate reductase or glutathione reductase. Ozone was more effective than sulfur dioxide in increasing the activities of the peroxidases. Ascorbate peroxidase activity increased 1.8-fold without a lag period during fumigation with 0.1 ppm ozone, while guaiacol peroxidase activity increased 4.4-fold with a 1-day lag. Expression of the APX1 gene encoding cytosolic ascorbate peroxidase was further investigated. Its protein levels in leaves exposed to 0.1 ppm ozone for 4 or 8 days were 1.5-fold higher than in controls. Both ozone and sulfur dioxide elevated APX1 mRNA levels in leaves at 4 and 7 days, whereas at 1 day only ozone was effective. The induction of APX1 mRNA levels by ozone (3.4- to 4.1-fold) was more prominent than that by sulfur dioxide (1.6-to 2.6-fold). The APX1 mRNA level increased by day and decreased by night. Exposure of plants to 0.1 ppm ozone enhanced the APX1 mRNA level within 3 h, which showed a diurnal rhythm similar to that of the control. These results demonstrate that near-ambient concentrations of ozone as well as similar concentrations of sulfur dioxide can induce APX1 gene expression in A. thaliana.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020979
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Cloning and characterization of differentially expressed genes in imbibed dormant and afterripened Avena fatua embryos (1995)
    Springer
    Plant molecular biology 29 (1995), S. 823-831 
    Details
    ISSN: 1573-5028
    Keywords: afterripening ; aldose reductase ; Avena fatua ; gene expression ; LEA ; seed dormancy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To analyze the patterns of gene expression associated with seed dormancy in wild oat (Avena fatua), we have isolated cDNA clones corresponding to genes that are differentially expressed in dormant and afterripened line M73 embryos. Gene transcripts of these clones were maintained in embryos of imbibed dormant caryopses, but declined rapidly in afterripened embryos after imbibition. GA3 treatment of dormant caryopses, which breaks dormancy, could lower the transcript levels in dormant embryos. When the germination of afterripened caryopses was inhibited by high temperature (35 °C), the decline in abundance of the transcripts in afterripened embryos was arrested. These genes were expressed to various degrees in water-stressed, but not in unstressed, 7-day-old seedlings. The expression of the genes was also ABA-inducible in afterripened embryos. The expression patterns in non-dormant line SH430 wild oat were similar to those of afterripened M73. DNA sequence analyses indicated that some of the cDNA clones encode LEA (late embryogenesis-abundant) proteins and aldose reductase. The significance of the expression of these genes in maintaining seed dormancy or longevity is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Molecular cloning and characterization of six cDNAs expressed during glucose starvation in excised maize (Zea mays L.) root tips (1995)
    Springer
    Plant molecular biology 28 (1995), S. 473-485 
    Details
    ISSN: 1573-5028
    Keywords: carbon catabolite repression ; cDNA ; gene expression ; stress-induced genes ; glucose-starvation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to isolate glucose-starvation-related cDNAs in maize (Zea mays L.) root tips, a cDNA library was constructed with poly(A)+ mRNA from 24 h starved root tips. After differential screening of the library, we isolated six different cDNAs (named pZSS2 and pZSS7) which were expressed during glucose starvation. Time course analysis revealed that maximum expression of five of these genes occurs 30 h after the onset of the starvation treatment. On the contrary, the expression of mRNAs corresponding to pZSS4 was maximal at an early stage of starvation and then dramatically decreased. The expression of this gene did not seem to be specific for glucose starvation. The pattern of induction of the genes corresponding to pZSS2, pZSS3, pZSS5, pZSS6 and pZSS7 revealed that non-metabolizable sugars such as L-glucose and mannitol induce mRNA transcription similarly to glucose starvation. When D-glucose or any other metabolizable sugar was supplied, the level of transcripts was reduced. Nucleotide sequence analyses of the six cDNAs allowed identification of five of them by comparison with sequence data bases. The protein encoded by clone pZSS2 is analogous to a wound-induced protein from barley. Clones pZSS4 to pZSS7 encode, respectively, a transmembrane protein, a cysteine protease, a metallothionein-like protein and a chymotrypsin/subtilisin-like protease inhibitor. Clone pZSS3 shares no significant homology with any known sequence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020395
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Cloning of a tomato polygalacturonase expressed in abscission (1995)
    Springer
    Plant molecular biology 28 (1995), S. 647-656 
    Details
    ISSN: 1573-5028
    Keywords: abscission ; gene expression ; polygalacturonase ; ethylene ; auxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Abscission, organ separation, is accompanied by cell wall breakdown in separation layer cells. In tomato (Lycopersicon esculentum), ethylene-induced abscission is correlated with an increase in polygalacturonase (PG) and endo-β-1,4-D-glucanase (cellulase) activity. We have identified a putative, abscission-specific cDNA clone for PG, pTAPG1. The TAPG1 cDNA has 43% identity at the amino acid level with the tomato fruit PG. Genomic blot analysis suggests that the gene for TAPG1 is a member of a small subfamily of PG genes that is distinct from the tomato fruit PG. The TAPG1 cDNA hybridizes to mRNA expressed during the course of ethylene-induced leaf and flower abscission. A high level of PG transcript accumulation coincides with the occurrence of abscission. Auxin, an abscission inhibitor, and silver thiosulfate, an ethylene action inhibitor, suppressed accumulation of mRNA in leaf abscission zones complementary to the TAPG1 cDNA. Expression of TAPG1 transcripts is several-fold higher in flower abscission zones than in leaf abscission zones. The identification of cDNAs that encode abscission-specific PG provide and additional tool to study the regulation of abscission and cell wall dissolution in separation layer cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00021190
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Intron-dependent transient expression of the maize GapA1 gene (1995)
    Springer
    Plant molecular biology 28 (1995), S. 667-676 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; promoter ; glyceraldehyde-3-phosphate dehydrogenase ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transient expression experiments show that the maize GapA1 promoter exhibits a requirement for sequences contained within intron 1 and surrounding exon border regions for expression in maize Black Mexican Sweet cells. Maize GapA1-promoter constructs lacking intron 1 are inactive. Intron 1 and its exon border sequences, when reintroduced into constructs lacking introns, restore gene activity whereas intron 2 and its exon borders to not. The minimal promoter so defined encompasses roughly 250 bp upstream of the in vivo transcription start and appears also to include intron 1. An octameric sequence was identified in intron 1 of maize GapA1 which is similar to sequence motifs found in other maize introns known to increase transient expression. Partial restoration of gene expression in GapA1 constructs lacking intron 1 was achieved through insertion of the identified octameric sequence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00021192
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Aerobic fermentation in tobacco pollen (1995)
    Springer
    Plant molecular biology 28 (1995), S. 739-750 
    Details
    ISSN: 1573-5028
    Keywords: alcohol dehydrogenase ; fermentation ; gene expression ; pollen ; pyruvate decarboxylase ; respiration ; tobacco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We characterized the genes coding for the two dedicated enzymes of ethanolic fermentation, alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC), and show that they are functional in pollen. Two PDC-encoding genes were isolated, which displayed reciprocal regulation: PDC1 was anaerobically induced in leaves, whereas PDC2 mRNA was absent in leaves, but constitutively present in pollen. A flux through the ethanolic fermentation pathway could be measured in pollen under all tested environmental and developmental conditions. Surprisingly, the major factor influencing the rate of ethanol production was not oxygen availability, but the composition of the incubation medium. Under optimal conditions for pollen tube growth, approximately two-thirds of the carbon consumed was fermented, and ethanol accumulated into the surrounding medium to a concentration exceeding 100 mM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00021197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Peroxisomal thiolase mRNA is induced during mango fruit ripening (1995)
    Springer
    Plant molecular biology 28 (1995), S. 811-820 
    Details
    ISSN: 1573-5028
    Keywords: β-oxidation ; gene expression ; fruit ripening ; Mangifera indica ; peroxisomes ; thiolase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fruit ripening is a complex, developmentally regulated process. A series of genes have been isolated from various ripening fruits encoding enzymes mainly involved in ethylene and cell wall metabolism. In order to aid our understanding of the molecular basis of this process in a tropical fruit, a cDNA library was prepared from ripe mango (Mangifera indica L. cv. Manila). By differential screening with RNA poly(A)+ from unripe and ripe mesocarp a number of cDNAs expressing only in ripe fruit have been isolated. This paper reports the characterization of one such cDNA (pTHMF 1) from M. indica which codes for a protein highly homologous to cucumber, rat and human peroxisomal thiolase (EC 2.3.1.16), the catalyst for the last step in the β-oxidation pathway. The cDNA for the peroxisomal mango thiolase is 1305 bp in length and codes for a protein of 432 amino acids with a predicted molecular mass of 45 532 Da. Mango thiolase is highly homologous to cucumber thiolase (80%), the only other plant thiolase whose cloning has been reported, and to rat and human thiolases (55% and 55% respectively). It is shown by northern analysis that during fruit ripening THMF 1 is up-regulated. A similar pattern of expression was detected in tomato fruit. Wounding and pathogen infection do not appear to affect THMF 1 expression. The possible involvement of thiolase in fatty acid metabolism during fruit ripening will be discussed. To our knowledge this is the first report cloning of a plant gene involved in fatty acid metabolism showing an induction during fruit ripening.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042067
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Molecular characterization of plastid pyruvate kinase from castor and tobacco (1995)
    Springer
    Plant molecular biology 27 (1995), S. 79-89 
    Details
    ISSN: 1573-5028
    Keywords: pyruvate kinase ; plastid ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clones encoding two different forms of plastid pyruvate kinase (PKp; EC 2.7.1.40) have been isolated from both castor and tobacco seed cDNA libraries. One form, designated PKpA, from castor was described in a previous report, and the tobacco homologue of PKpA has now been isolated. In addition, a second cDNA, designated PKpG, has been identified and sequenced in both species. Western blot analysis, using antibodies raised against protein overexpressed from these clones, indicates that they encode the two predominant polypeptides of plastid pyruvate kinase from developing castor endosperm. In castor, both PKpA and PKpG are encoded by single genes. In the allotetraploid Nicotiana tabacum, there are two copies of each, one derived from each of the progenitors of this species. The expression of the genes for PKpA and PKpG was examined in various tissues from both castor and tobacco. In castor, both forms are expressed in developing and germinating endosperm and in the root but neither is expressed in the leaf. In tobacco, both forms are expressed in developing seeds but in mature tissues, PKpA is most abundant in roots and PKpG in leaves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019180
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    The phenylalanine ammonia-lyase gene family in Arabidopsis thaliana (1995)
    Springer
    Plant molecular biology 27 (1995), S. 327-338 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; multi-gene family ; phenylalanine ammonia-lyase ; phenylpropanoids ; promoters ; secondary metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phenylpropanoid derivatives are a complex class of secondary metabolites that have many important roles in plants during normal growth and in responses to environmental stress. Phenylalanine ammonialyase (PAL) catalyzes the first step in the biosynthesis of phenylpropanoids, and is usually encoded by a multi-gene family. Genomic clones for three Arabidopsis thaliana PAL genes containing the entire protein-coding region and upstream and downstream sequences have been obtained and completely sequenced. Two A. thaliana PAL genes (PAL1 and PAL2) are structurally similar to PAL genes that have been cloned from other plant species, with a single intron at a conserved position, and a long highly conserved second exon. Previously identified promoter motifs plus several additional sequence motifs were found in the promoter regions of PAL1 and PAL2. Expression of PAL1 and PAL2 is both qualitatively and quantitatively similar in different plant organs and under various inductive conditions. A third A. thaliana PAL gene, PAL3, differs significantly from PAL1 and PAL2 and other sequenced plant PAL genes. PAL3 contains an additional intron, and its deduced amino acid sequence is less homologous to other PAL proteins. The PAL3 promoter region lacks several sequence motifs conserved between A. thaliana PAL1 and PAL2, as well as motifs described in other genes involved in phenylpropanoid metabolism. A. thaliana PAL3 was expressed at very low levels under the conditions examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020187
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    A type I element composed of the hexamer (ACGTCA) and octamer (CGCGGATC) motifs plays a role(s) in meristematic expression of a wheat histone H3 gene in transgenic rice plants (1995)
    Springer
    Plant molecular biology 27 (1995), S. 17-26 
    Details
    ISSN: 1573-5028
    Keywords: cis factor ; gene expression ; promoter ; transgenic rice ; wheat histone H3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Type I element (CCACGTCACCGATCCGCG) is a well-conserved regulatory element found in proximal promoter region of a certain class of plant histone genes, that is composed of two independent cis-acting elements of the hexamer (ACGTCA) and the reverse-oriented octamer (GATCCGCG) motifs. To investigate functional role(s) of the type I element in regulation of a wheat histone H3 gene (TH012) promoter activity in vivo, base substitution mutations were introduced into the element and activities of the mutated promoters were examined in cultured rice cells, and in regenerated roots and anther walls of transgenic rice plants by employing a GUS reporter system. Mutations of each or both of the hexamer and the octamer motifs caused a reduction in the promoter activity in protoplasts transfected transiently or stably transformed calli. The mutation of the octamer motif with or without the mutation of the hexamer motif caused a marked reduction of the promoter activity in the root meristem of transgenic rice although the mutation of the hexamer motif alone caused a weak reduction. In contrast to these results, no effect of the mutations of either the hexamer or the octamer motif was found in the anther wall in which replication-independent activity of the H3 promoter was observed. Our results suggested that the hexamer and the octamer motifs may play important role(s) in regulation of replication-dependent but not of replication-independent expression of the wheat histone H3 gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019175
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    GASA, a gibberellin-regulated gene family from Arabidopsis thaliana related to the tomato GAST1 gene (1995)
    Springer
    Plant molecular biology 27 (1995), S. 743-752 
    Details
    ISSN: 1573-5028
    Keywords: plant hormone ; gibberellic acid ; GA-responsive ; gene expression ; HCA ; hydrophobic cluster analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A multiple gene family of at least four members, related to a GA-stimulated transcript (GAST1) from tomato, was characterized in Arabidopsis thaliana by analysing four related cDNAs, named GASA1 to GASA4. The corresponding peptides display comparable structural features: (1) a putative signal peptide of 18 to 23 residues; (2) a highly divergent hydrophilic region of about 22 amino acids; (3) a conservative 60 amino acid C-terminal domain containing 12 cysteines. This organization has also bean shown in two related peptides from tomato, GAST1 found in shoots and RSI-1 found in early lateral roots. Southern blot hybridization patterns showed single-copy genes for all four members of the GASA family. Accumulation of the various transcripts, monitored by northern blot hybridization, indicated that the various genes are expressed differentially in plant organs. Specific mRNAs were mostly detected in flower buds and immature siliques in the case of GASA1, in siliques and dry seeds in the case of GASA2 and 3, and in growing roots and flower buds in the case of GASA4. At least two of the GASA genes are activated in GA-deficient mutant ga5, as early as 4 to 8 h after spraying with 50 μM GA3. The complex patterns of expression and regulation of the various genes suggest that the related peptides are involved in a developmental regulation process in Arabidopsis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020227
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Molecular cloning of two novel rice cDNA sequences encoding putative calcium-dependent protein kinases (1995)
    Springer
    Plant molecular biology 27 (1995), S. 953-967 
    Details
    ISSN: 1573-5028
    Keywords: calcium-dependent protein kinase ; gene expression ; protein phosphorylation ; rice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have isolated, from a cDNA library constructed from rice coleoptiles, two sequences, OSCPK2 and OSCPK11, that encode for putative calcium-dependent protein kinase (CDPK) proteins. OSCPK2 and OSCPK11 cDNAs are related to SPK, another gene encoding a rice CDPK that is specifically expressed in developing seeds [20]. OSCPK2 and OSCPK11-predicted protein sequences are 533 and 542 amino acids (aa) long with a corresponding molecular mass of 59436 and 61079 Da respectively. Within their polypeptide chain, they all contain those conserved features that define a plant CDPK; kinase catalytic sequences are linked to a calmodulin-like regulatory domain through a junction region. The calmodulin-like regulatory domain of the predicted OSCPK2 protein contains 4 EF-hand calcium-binding sites while OSCPK11 has conserved just one canonical EF-hand motif. In addition, OSCPK2-and OSCPK11-predicted proteins contain, at their N-terminal region preceding the catalytic domain, a stretch of 80 or 74 residues highly rich in hydrophilic amino acids. Comparison of the NH2-terminal sequence of all three rice CDPKs so far identified (OSCPK2, OSCPK11 and SPK) indicates the presence of a conserved MGxxC(S/Q)xxT motif that may define a consensus signal for N-myristoylation. OSCPK2 and OSCPK11 proteins are both encoded by a single-copy gene and their polyadenylated transcripts are 2.4 and 3.5 kb long respectively. OSCPK2 and OSCPK11 mRNAs are equally abundant in rice roots and coleoptiles. A 12 h white light treatment of the coleoptiles reduces the amount of OSCPK2 mRNA with only a slight effect on the level of OSCPK11 transcript. With anoxic treatments, OSCPK2 mRNA level declined significantly and promptly while the amount of OSCPK11 transcript remained constant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00037023
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Isolation, sequence and expression in Escherichia coli of the nitrite reductase gene from the filamentous, thermophilic cyanobacterium Phormidium laminosum (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1037-1042 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; cyanobacterium ; nitrite reductase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nitrite reductase (NiR) gene (nirA) has been isolated and sequenced from the filamentous, thermophilic non-N2-fixing cyanobacterium Phormidium laminosum. Putative promoter-like and Shine-Dalgarno sequences appear at the 5′ end of the 1533 bp long nir-coding region. The deduced amino acid sequence of NiR from P. laminosum corresponds to a 56 kDa polypeptide, a size identical to the molecular mass previously determined for the pure enzyme, and shows a high identity with amino acid sequences from ferredoxin-dependent NiR. This cyanobacterial NiR gene has been efficiently expressed in Escherichia coli DH5α from the E. coli lac promoter and probably from the P. laminosum NiR promoter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00037030
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Structure of a maize tryptophan synthase alpha subunit gene with pith enhanced expression (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1183-1188 
    Details
    ISSN: 1573-5028
    Keywords: differential screening ; maize ; pith ; trpA ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA derived from an abundant maize pith mRNA transcript and its corresponding genomic equivalent have been isolated and characterized. High transcript levels are seen in the pith and young leaves of maize plants, while no transcript is detected in seed tissue of any age. The protein encoded by the isolated gene has considerable homology with tryptophan synthase alpha subunit (trpA) from other organisms and the cDNA clone can complement an E. coli trpA mutant. These data support the conclusion that this cDNA and the corresponding genomic clone encode a maize trpA protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020891
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Isolation of a novel Arabidopsis ozone-induced cDNA by differential display (1995)
    Springer
    Plant molecular biology 29 (1995), S. 91-98 
    Details
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; gene expression ; hypersensitive response ; oxidative stress ; ozone ; pathogenesis-related proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have used a reverse transcriptase polymerase chain reaction procedure (differential display) to isolate cDNAs corresponding to transcripts that accumulate in ozone-treated Arabidopsis thaliana. In this report we describe the characterization of an ozone-induced transcript, AtOZI1. AtOZI1 mRNA in untreated plants was detected at low levels in cotyledons, leaves, and flower buds and at higher levels in roots and mature flowers. AtOZI1 mRNA accumulation was transiently induced in leaves 3- to 5-fold within the first 6 h of ozone treatment. AtOZI1 mRNA accumulation was also transiently induced 3- to 6-fold by photopathogenic Pseudomonas strains. Sequence analysis of AtOZI1 revealed that it encodes a 8.6 kDa basic protein that contains a putative signal peptide and two potential phosphorylation sites. Our results suggest that AtOZI1 represents a novel stress-related protein that accumulates in response to the production of active oxygen species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Molecular study of a light-harvesting apoprotein of Giraudyopsis stellifer (Chrysophyceae) (1995)
    Springer
    Plant molecular biology 29 (1995), S. 135-148 
    Details
    ISSN: 1573-5028
    Keywords: chromophyte ; Chrysophyceae ; light-harvesting complex protein gene ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have isolated a gene from a library of nuclear DNA for a chlorophyll a/c-binding protein (named Cac for chl a/c by analogy with Cab for chl a/b) of a chromophyte alga, Giraudyopsis stellifer, and sequenced it. The comparison of the deduced amino acid sequence with other chl a/c-and chl a/b-binding protein sequences shows that structural and functional features, i.e. the arrangement ‘en X’ of the two A and B transmembrane helices and the putative chl a-binding sites, are shared by both Chlorophyta and Chromophyta. Moreover, in contrast to Chlorophyta, a very strong identity is found among Chromophyta in the C helix, suggesting a major function associated to this specific region. Nevertheless, the primary structure of the apoprotein does not seem affected by the pigment composition in Chromophyta. As in the few other examples currently known, we confirm that the cac genes are nuclear-encoded and are part of a multigenic family. Northern blots, performed on poly(A)+ mRNA from G. stellifer, give evidence that the cac gene is light-induced at a transcriptional level and that no expression can be observed in the dark.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Isolation and expression pattern of a cDNA encoding a cathepsin B-like protease from Nicotiana rustica (1995)
    Springer
    Plant molecular biology 29 (1995), S. 379-384 
    Details
    ISSN: 1573-5028
    Keywords: cathepsin B ; gene expression ; Nicotiana ; thiol protease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sequence analysis of a 1.33 kb clone from a root cDNA library of Nicotiana rustica revealed an open reading frame encoding a protein of 356 amino acids. The deduced protein has high levels of homology to human cathepsin B protease and a cathepsin B-like cysteine protease from wheat but much lower levels of homology with other plant cysteine proteinases. Southern blotting experiments suggest a limited number of cathepsin B-like genes are present in the genome of N. rustica and also that of N. tabacum. RNA analysis involving a range of tissues, harvested from both Nicotiana species 4–5 h after the beginning of a 16 h photoperiod, revealed the cathepsin B-like gene was being expressed strongly in roots, stem and developing flowers but weakly in mature leaves. Further analysis of RNA extracted from leaf tissue of N. tabacum revealed the gene showed rhythmic expression and also that its expression increased in response to wounding. Analysis of leaf tissues harvested during the latter part of a 16 h photoperiod (11 and 16 h after illumination commenced) showed that transcript levels were two three times higher than in leaf tissue harvested either towards the end of the dark period or 5 h after illumination commenced. When leaf tissue was wounded at 11:00 (5 h after plants were illuminated), and harvested for RNA extraction 6 h later, the level of cathepsin B-like transcript in mesophyll tissue was found to be increased ca. 2-fold relative to the level detected in unwounded controls.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00043660
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Tissue-specific and light-responsive regulation of the promoter region of the Arabidopsis thaliana chloroplast ω-3 fatty acid desaturase gene (FAD7) (1995)
    Springer
    Plant molecular biology 29 (1995), S. 599-609 
    Details
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; chloroplast ; gene expression ; ω-3 fatty acid desaturase ; promoter ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Arabidopsis FAD7 gene encodes a chloroplast ω-3 fatty acid desaturase that catalyzes the desaturation of lipid-linked dienoic fatty acids (18:2 and 16:2). An 825 bp FAD7 promoter fragment upstream from the transcriptional start point contained several short sequences which were homologous to the cis-elements (box II, G-box, etc.) conserved in many light-responsive genes. We introduced the FAD7 promoter fused to the β-glucuronidase (GUS) or the luciferase (LUC) reporter gene into tobacco plants. The −825 promoter sequence conferred tissue-specific and light-responsive expression to both these reporter genes in transgenic tobacco, indicating that these expressions of the FAD7 gene were regulated mainly at the transcriptional level. Histochemical GUS staining showed that the activity of the FAD7 promoter is restricted to the tissues with chloroplast-containing cells although the staining was noticeably absent in the chloroplast-containing cells associated with vascular systems. The 5′ deletion experiments of the promoter revealed that the −362/ −166 region, containing two putative box II sequences, was responsible for the tissue-specific and light-responsive expression of the FAD7 gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020987
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Differential regulation of polygalacturonase and pectin methylesterase gene expression during and after heat stress in ripening tomato (Lycopersicon esculentum Mill.) fruits (1995)
    Springer
    Plant molecular biology 29 (1995), S. 1101-1110 
    Details
    ISSN: 1573-5028
    Keywords: tomato ; polygalacturonase ; pectin methylesterase ; heat stress ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of extended heat stress on polygalacturonase (PG; EC 3.2.1.15) and pectin methylesterase (PME; EC 3.1.1.11) gene expression at mRNA, protein and activity levels in ripening tomato fruits were investigated. Steady state levels of PG mRNA declined at temperatures of 27°C and above, and a marked reduction in PG protein and activity was observed at temperatures of 32°C and above. Exogenous ethylene treatment did not reverse heat stress-induced inhibition of PG gene expression. Transfer of heat-stressed fruits to 20°C partly restored PG mRNA accumulation, but the rate of PG mRNA accumulation declined exponentially with duration of heat stress. Heat stress-induced inhibition of PME mRNA accumulation was recoverable even after 14 days of heat stress. In fruits held at 34°C, both PG and PME protein and activity continued to accumulate for about 4 days, but thereafter PG protein and activity declined while little change was observed in PME protein and activity. In spite of increases in mRNA levels of both PG and PME during the recovery of heat-stressed fruit at 20°C, levels of PG protein and activity declined in fruits heat-stressed for four or more days while PME protein and activity levels remained unchanged. Collectively, these data suggest that PG gene expression is being gradually and irreversibly shut off during heat stress, while PME gene expression is much less sensitive to heat stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020455
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    The phytochrome gene family in tomato includes a novel subfamily (1995)
    Springer
    Plant molecular biology 29 (1995), S. 1143-1155 
    Details
    ISSN: 1573-5028
    Keywords: gene family ; gene expression ; photoreceptor ; phytochrome ; tomato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Data presented here define five tomato phytochrome genes (PHY) and indicate the existence of additional PHY in the tomato genome. Portions of each gene, encoding amino acids 203 through 315 in a consensus amino acid sequence, were amplified by polymerase chain reaction. Four of these genes, PHYA, PHYB1, PHYB2 and PHYE, are members of previously identified PHY subfamilies, while the fifth, PHYF, is identified as a member of a new PHY subfamily. PHYA, PHYB1, PHYB2 and PHYE fragments encode amino acid sequences that share 88% to 98% sequence identity with their Arabidopsis counterparts. The PHYF fragment, however, encodes a polypeptide that shares only 65% to 74% sequence identity with previously identified Arabidopsis phytochromes. A phylogenetic analysis suggests that PHYF arose soon after, or perhaps prior to, the origin of angiosperms. This analysis leads to the prediction that PHYF might be widespread among angiosperms, including both monocotyledons and dicotyledons. Each of the five tomato PHY is expressed as a transcript of sufficient size to encode a full-length phytochrome apoprotein. Two PHYF transcripts, 4.4 and 4.7 kb in length, have been detected in 9-day-old light-grown seedlings, consistent with either multiple transcription start sites or differential processing. Analyses of genomic Southern blots hybridized with radiolabelled RNA probes derived from the five tomato PHY, as well as Arabidopsis PHYC, indicate that the tomato genome contains as many as 9 to 13 PHY. The tomato PHY family is apparently not only different from, but also larger than, the PHY family presently described for Arabidopsis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020458
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Protons and calcium modulate SV-type channels in the vacuolar-lysosomal compartment — channel interaction with calmodulin inhibitors (1995)
    Springer
    Planta 197 (1995), S. 655-671 
    Details
    ISSN: 1432-2048
    Keywords: Calcium ; Calmodulin antagonists ; pH ; SV-type channels (vacuole) ; Taproot, guard cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Slowly activating vacuolar (SV-type; Hedrich and Neher 1987, Nature 329: 833–835) ion channels provide the predominant membrane conductance of the vacuolar-lysosomal compartment of Vicia faba L. guard cells and sugar beet (Beta vulgaris L.) taproots. Applying the patch-clamp technique to isolated vacuoles of both tissues, the electrical and pharmacological properties of guard-cell SV-type currents were studied and compared to the sugar beet channel with regard to its modulation by cytoplasmic Ca2+ and pH. This outward rectifier of V. faba guard cells showed a half-maximum activation at 55–60 mV with an apparent gating charge equivalent of z ≈ 4. Studies on the single-channel and whole-vacuole level revealed an extremely high conductance of 280 pS for the guard-cell channels at a mean density of 0.37 μm-2 compared to taproots (120–140 pS at about 0.16 channels per μm2). Guard-cell SV-type channels are weakly selective for cations over anions and lack saturation at KC1 concentrations of up to 1 M. Since in the absence of physiological K+ concentrations, Ca2+ is the major permeable ion, relative changes in the amounts of the two ions might control the permeation process. In spite of their different origins and physiological functions, in guard cells and beet taproot cells, cytoplasmic Ca2+ and protons, both considered as candidates for intracellular signalling in plants, modulate the voltage dependence of SV-type channels. While the two effectors do not alter the single-channel conductance, they strongly interact with the voltage sensor. The calmodulin (CaM) antagonists N-(6-aminohexyl)-5-chloro-l-naphthalenesulfonamide hydrochloride (W-7), trifluoperazine (TFP) and calmidazolium hydrochloride (R 24571) effectively blocked the channel in an antagonist-specific manner. In agreement with the properties of a Ca2+-permeable channel, CaM could be involved in the modulation of the activation threshold of the SV-type channel. We therefore conclude that guard-cell SV-type channels, which might be responsible for the release of K+, Cl- and to a smaller extent Ca2+ during stomatal closure, could serve as an intracellular sensor for changes in cytosolic calcium (calcium-CaM) and pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191574
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    ATP, pH and Mg2+ modulate a cation current in Beta vulgaris vacuoles: A possible shunt conductance for the vacuolar H+-ATPase (1995)
    Springer
    The journal of membrane biology 145 (1995), S. 75-86 
    Details
    ISSN: 1432-1424
    Keywords: Amino acid transport ; ATP regulation ; Beta ; Mg2+ ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Macroscopic instantaneous and time-dependent currents have been measured in the vacuolar membrane of Beta vulgaris using a patch clamp configuration analogous to whole cell mode. At low cytosolic Ca2+ and in the absence of Mg2+, only an instantaneous current was observed. This current is carried predominantly by cations (PK∶PCl 7∶1, pna∶pcl 4∶1 and arginine is also conducted). The instantaneous current can be activated by ATP4− (e.g., ATP-activated mean K+ current density was −20 mA.m−2 at a membrane voltage of −20 mV) and by increasing cytosolic pH and Mg2+ (raising Mg2+ from 0 to 0.4 mm induced a mean current density increase of −7 mA.m−2 at −20 mV). Such current can be activated by simultaneous addition of putative in vivo concentrations of ATP4−/MgATP/Mg free 2+ (in the presence of bafilomycin to inhibit the vacuolar ATPase) and further modulated by cytosolic pH. With vacuolar K+ concentration greater than that of the cytosol, activation of the instantaneous current would mediate vacuolar K+ release over the range of physiological membrane voltage. It is argued that the ATP4−-activated current, in addition to acting as a K+ mobilization pathway, could provide a counter-ion (shunt) conductance, allowing the two electrogenic H+ pumps which reside in the vacuolar membrane to acidify the vacuolar lumen. A separate time-dependent current, which was not observed at low Ca2+ concentrations (less than 500 nm) could also be elicited by addition of Mg2+ at the cytoplasmic membrane face. This current was stimulated by increasing cytoplasmic pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    The pH-sensitivity of transepithelial K+ transport in vestibular dark cells (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 255-262 
    Details
    ISSN: 1432-1424
    Keywords: Labyrinth ; Slowly activating K+ channel ; IsK channel ; MinK channel ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The pH-sensitivity of transepithelial K+ transport was studied in vitro in isolated vestibular dark cell epithelium from the gerbil ampulla. The cytosolic pH (pH iwas measured microfluorometrically with the pH-sensitive dye 2′,7′-bicarboxyethyl-5(6)-carboxyfluorescein (BCECF) and the equivalent short-circuit current (I sc), which is a measure for transepithelial K+ secretion, was calculated from measurements of the transepithelial voltage (V t)and the transepithelial resistance (R t) in a micro-Ussing chamber. All experiments were conducted in virtually HCO 3 − -free solutions. Under control conditions, pH iwas 7.01±0.04 (n=18), V twas 9.1±0.5 mV, R t16.7±0.09 Ωcm2, and I sc was 587±30 μA/cm2 (n=49). Addition of 20 mm propionate− caused a biphasic effect involving an initial acidification of pH i, increase in V tand I sc and decrease in R tand a subsequent alkalinization of pH i, decrease of V tand increase of R t. Removal of propionate− caused a transient effect involving an alkalinization of pH i, a decrease of V tand I sc and an increase in R t. pH iin the presence of propionate− exceeded pH iunder control conditions. Effects of propionate − on V t, R tand I sc were significantly larger when propionate− was applied to the basolateral side rather than to the apical side of the epithelium. The pH i-sensitivityof I sc between pH 6.8 and 7.5 was −1089 μA/(cm2 · pH-unit) suggesting that K+ secretion ceases at about pH i7.6. Acidification of the extracellular pH (pH o)caused an increase of V tand I sc and a decrease of R tmost likely due to acidification of pH i. Effects were significantly larger when the extracellular acidification was applied to the basolateral side rather than to the apical side of the epithelium. The pH osensitivity of I sc between pH 7.4 and 6.4 was −155 μA/(cm2 · pH unit). These results demonstrate that transepithelial K+ transport is sensitive to pH iand pH oand that vestibular dark cells contain propionate− uptake mechanism. Further, the data suggest that cytosolic acidification activates and that cytosolic alkalinization inactivates the slowly activating K+ channel (I sK)in the apical membrane. Whether the effect of pH ion the I sK channel is a direct or indirect effect remains to be determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    pH- and voltage-dependent conductances in toad skin (1995)
    Springer
    The journal of membrane biology 148 (1995), S. 1-11 
    Details
    ISSN: 1432-1424
    Keywords: Toad skin ; pH ; Ion conductance ; Voltage dependence ; Chloride conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The present study focuses on two closely related topics on ion conductance in toad skins: (i) the interaction of apical protons with the apical voltage-dependent Cl−-activated channels of the mitochondriarich cells, and (ii) the description and characterization of a novel subject, a voltage-dependent H+-activated conductance. The Cl− conductance (G Cl) is activated by tissue hyperpolarization (which leads to apical membrane depolarization) and the presence of Cl− ions in the apical solution. Increasing apical proton concentration (from pH 8 to pH 4) impairs the process of activation of the Cl− conductive pathway, slowing the kinetics of I t activation and reducing the steady-stage values of G t and I t . This effect is markedly voltage-dependent since no effect is seen at V t =−100 mv and is fully present at −50 mV. The voltage-dependence of the pH effect suggests that the critical protonation sites of the apical Cl− channels are not freely exposed to the apical solution but dwell within the membrane electric field. An also coherent interpretation is that titration of apical proton binding sites affects the gating of the voltage-dependent Cl− channels, shifting the conductance-vs.-voltage curve to more negative clamping potentials. Tissue conductance in the absence of apical Cl− ions can be importantly affected by the pH of the apical solution (pH a ), the effect being markedly dependent on the clamping potential. Generally speaking, the effect of rising apical proton concentration can be conspicuous at negative clamping potentials, while at positive potentials changes in tissue conductance were never observed. For a clamping potential of −100 mV, a turning point somewhere between pH a =4 and pH a =3 was observed. Apical acidification to pH 4 has no effect upon tissue conductance while apical acidification to pH 3 leads to a marked, slow and reversible increase of tissue conductance. A striking similitude exists between the voltage-dependent Cl−-gated conductance and the voltage-dependent proton-gated conductance regarding: (i) slow time courses of activation and deactivation, (ii) requirement for a negative clamping potential and the presence of a specific ion species in the apical solution for activation to take place, (iv) instantaneous ohmic behavior, and (v) steady-state rectification. However, so far the results do not permit one to conclude definitely that the voltage-dependent Cl−-gated conductance and the voltage-dependent proton-gated conductance share a common pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234151
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    A voltage-dependent and pH-sensitive proton current in Rana esculenta oocytes (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 207-215 
    Details
    ISSN: 1432-1424
    Keywords: Rana esculenta oocytes ; H+ current ; pH ; Voltage clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Voltage clamp technique was used to study macroscopic ionic currents in Rana esculenta oocytes. Depolarization steps led to the activation of a single type of outward current (I out) when contaminant potassium and calcium-dependent chloride currents were pharmacologically inhibited. The voltage threshold of I out activation was 10 mV and this current, which did not inactivate, presented a deactivation the time constant of 73±21 msec (n=26) corresponding to a membrane voltage of −60 mV. Its reversal potential (E rev) was dependent on the magnitude of the depolarization and also on pulse duration. These changes in E rev were thought to reflect intracellular ion depletion occurring during activation of the remaining outward current. Furthermore, the activation threshold of I out was clearly affected by modifications in extracellular and intracellular H+ concentrations. Indeed, intracellular alkalinization (evoked by external application of ammonium chloride) or extracellular acidification induced a rightward shift in the activation threshold while intracellular acidification (evoked by external application of sodium acetate) or extracellular alkalinization shifted this threshold toward a more negative value. Lastly, I out was dramatically reduced by divalent cations such as Cd2+, Ni2+ or Zn2+ and was strongly decreased by 4 Aminopyridine (4-AP), wellknown H+ current antagonists already described in many cell types. Therefore, it was suggested that the outward current was prominently carried by H+ ions, which may play a key role in the regulation of intracellular pH and subsequent pH dependent processes in Rana oocyte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233548
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Differential regulation of membrane potential and conductance via intra-and extracellular pH in fused proximal tubular cells of frog kidney (1995)
    Springer
    The journal of membrane biology 143 (1995), S. 123-134 
    Details
    ISSN: 1432-1424
    Keywords: Membrane potential ; Conductances ; pH ; Acetate ; NH4C1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Intracellular pH (pH i ), membrane potential (V m ) and membrane conductance (G m ) in fused proximal tubular cells of the frog kidney, were determined at three extracellular pH (pH o ) values, 7.5, 8.5 and 6.5. Imposed changes of pH o by ±1 pH unit induced parallel but smaller shifts of pH i . The alkaline milieu hyperpolarized the cells and increased G m , whereas the acid milieu depolarized and lowered G m . We subsequently introduced a weak acid and its conjugate base (acetic acid/acetate), or a weak base and its conjugate acid (NH3/NH 4 + ), at pH o 7.5, 8.5 and 6.5 to shift pH i -without altering pH o , or to shift pH i against imposed changes of pH o . From these experiments, we observed that under some circumstances V m varied with pH o but without G m or pH i changes, whereas under other circumstances changes of G m occurred during alterations of pH i while pH o and V m remained unaltered. At pH i ≈ 6.5 associated with V m ≈ −10 mV, G m dramatically increased to quasi-infinite values. This increase was not an artifact since G m returned to its control value following recovery to the control solution or in the presence of hyperosmotic solution. In conclusion, we demonstrate a differential regulation whereby V m and G m are controlled by pH o and pH i : pH o modulates mainly V m , and pH i modulates chiefly G m . Furthermore, at pH i ≈ 6.5 and V m ≈ −10 mV, our data reveal a large G m that tends towards infinite values in a reversible fashion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234658
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Characterization of a chloride channel reconstituted from cardiac sarcoplasmic reticulum (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 121-136 
    Details
    ISSN: 1432-1424
    Keywords: Chloride channel ; Cardiac sarcoplasmic reticulum ; Planar lipid bilayer ; Ion selectivity ; Voltage ; Block ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have characterized a voltage-sensitive chloride channel from cardiac sarcoplasmic reticulum (SR) following reconstitution of porcine heart SR into planar lipid bilayers. In 250 mm KCl, the channel had a main conductance level of 130 pS and exhibited two substrates of 61 and 154 pS. The channel was very selective for Cl− over K+ or Na+ ( $$P_{{\text{K}}^{\text{ + }} } /P_{{\text{Cl}}^{\text{ - }} } = 0.012$$ and $$P_{{\text{Na}}^{\text{ + }} } /P_{{\text{Cl}}^{\text{ - }} } \sim 0.040$$ ). It was permeable to several anions and displayed the following sequence of anion permeability: SCN− 〉 I− 〉 NO 3 − ∼ Br− 〉 Cl− 〉 f− 〉 HCOO−. Single-channel conductance saturated with increasing Cl− concentrations (K m= 900 mm and γmax = 488 pS). Channel activity was voltage dependent, with an open probability ranging from ∼1.0 around 0 mV to ∼0.5 at +80 mV. From −20 to +80 mV, channel gating was time-independent. However, at voltages below −40 mV the channel entered a long-lasting closed state. Mean open times varied with voltage, from ∼340 msec at −20 mV to ∼6 msec at +80 mV, whereas closed times were unaffected. The channel was not Ca2+-dependent. Channel activity was blocked by disulfonic stilbenes, arylaminobenzoates, zinc, and cadmium. Single-channel conductance was sensitive to trans pH, ranging from ∼190 pS at pH 5.5 to ∼60 pS at pH 9.0. These characteristics are different from those previously described for Cl− channels from skeletal or cardiac muscle SR.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Differential regulation of Na+/H+ exchange and H+ -ATPase by pH and HCO 3 − in kidney proximal tubules (1995)
    Springer
    The journal of membrane biology 144 (1995), S. 209-216 
    Details
    ISSN: 1432-1424
    Keywords: Na+/H+ exchange ; H+-ATPase ; Proximal tubules ; Kidney ; Acid-base ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This study examines the effects of acute in vitro acid-base disorders on Na+/H+ and H+-ATPase transporters in rabbit kidney proximal tubules (PT). PT suspensions were incubated in solutions with varying acid base conditions for 45 min and utilized for brush border membrane (BBM) vesicles preparation. BBM vesicles were studied for Na+/H+ exchange activity (assayed by 22Na+ influx) or abundance (using NHE-3 specific antibody) and H+-ATPase transporter abundance (using antibody against the 31 kDa subunit). The Na+/ H+ exchanger activity increased by 55% in metabolic acidosis (pH 6.5, HCO 3 − 3 mm) and decreased by 41% in metabolic alkalosis (pH 8.0, HCO 3 − 90 mm). The abundance of NHE-3 remained constant in acidic, control, and alkalotic groups. H+-ATPase abundance, however, decreased in metabolic acidosis and increased in metabolic alkalosis by 57% and 42%, respectively. In PT suspensions incubated in isohydric conditions (pH 7.4), Na+/H+ exchanger activity increased by 29% in high HCO 3 − group (HCO 3 − 96 mm) and decreased by 16% in the low HCO 3 − groups (HCO 3 − 7mm. The NHE-3 abundance remained constant in high, normal, and low [HCO 3 − ] tubules. The abundance of H+-ATPase, however, increased by 82% in high [HCO 3 − ] and decreased by 77% in the low [HCO 3 − ] tubules. In PT suspensions incubated in varying pCO2 and constant [HCO 3 − ], Na+/H+ exchanger activity increased by 35% in high pCO2 (20% pCO2, respiratory acidosis) and decreased by 32% in low pCO2 (1.5% pCO2, respiratory alkalosis) tubules. The NHE-3 abundance remained unchanged in high, normal, and low pCO2 tubules. However, the H+-ATPase abundance increased by 74% in high pCO2 and decreased by 69% in low pCO2 tubules. The results of these studies suggest that the luminal Na+/H+ exchanger is predominantly regulated by pH whereas H+-ATPase is mainly regulated by [HCO 3 − ] and/ or pCO2. They further suggest that the adaptive changes in H+-ATPase transporter are likely mediated via endocytic/exocytic pathway whereas the adaptive changes in Na+/H+ exchanger are via the nonendocytic/exocytic pathway. The excellent technical assistance of Yollanda J. Hattabaugh, Gwen L. Bizal, and L. Yang is greatly appreciated. Portions of these studies were presented at the annual meeting of the American Society of Nephrology, Boston, MA, November 1993, and published in abstract form (J.Am.Soc.Neph. 4:840A, 1993)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236834
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Effects of internal ph on the nonselective cation channel from the mouse collecting tubule (1995)
    Springer
    The journal of membrane biology 148 (1995), S. 83-90 
    Details
    ISSN: 1432-1424
    Keywords: Cation channel ; pH ; Nucleotides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We investigated the effects of internal pH on Ca-activated, nucleotide-inhibited nonselective cation channels in the basolateral membranes of mouse collecting tubules, using the inside-out variant of the patch clamp technique. pH modulated the channel open probability (P o ), giving a bell-shaped curve peaking at pH 6.8/7.0: P o at pH 6.0 was 11±6% of P o at pH 7.2 and 32 ±7% at pH 8.0. The open and closed time distributions, best fitted to the sum of two exponentials, were differently sensitive to acid and alkaline conditions. Low pH reduced the short and long open times to 38 and 24% of their pH 7.2 values, while high pH produced a 4-fold increase in the long closed time. As previously reported, 4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid (SITS) induced a quasi-permanent opening of the channel. The inhibition of the channel produced by high pH disappeared in the presence of SITS, while the inhibition produced by low pH was unaffected. These results suggest that the pH dependence of the channel is due to two separate mechanisms. pH was without effect on the ATP-evoked inhibition of the channel, while high pH profoundly reduced the steepness of the AMP inhibition curve, without altering the half-maximal inhibitory AMP concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234159
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Restricted tissue-specific but correct developmental expression mediated by a short human α1AT promoter fragment in transgenic mice (1995)
    Springer
    Transgenic research 4 (1995), S. 70-74 
    Details
    ISSN: 1573-9368
    Keywords: human α1AT ; CAT ; transgenic mice ; gene expression ; liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The tissue-specific and developmental pattern of expression controlled by the proximal promoter (position −348 to+15) derived from the human α-1-antitrypsin (hα1AT) gene was studied in transgenic mice. The short promoter segment was linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The transgene showed highly specific expression in the liver and the correct developmental pattern of regulation. Interestingly, this short promoter targets expression to the liver with a greater specificity than that reported for larger α1AT promoter fragments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01976504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Anin vivo analysis of transcriptional elements in the mouse α-myosin heavy chain gene promoter (1995)
    Springer
    Transgenic research 4 (1995), S. 397-405 
    Details
    ISSN: 1573-9368
    Keywords: gene expression ; transgenic mice ; thyroid hormone ; thyroid hormone response element ; muscle ; heart
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During development in the murine ventricle, there is a switch in myosin heavy chain gene (MyHC) transcription. The β-MyHC is expressed in the ventricles during foetal development, but is shut down at or around birth, at which time α-MyHC transcription is activated. This antithetical switch is thought to be mediated by circulating levels of thyroid hormone (TH) and both low and high affinity thyroid response elements (TREs) have been identified in the proximal promoter region of the murine α-MyHC. Myosin gene expression in the atria is relatively unaffected by the TH status. Previously, we used site-directed mutagenesis of the promoter in a transgenic analysis to define those elements responsible for high levels of transcriptionin vivo. These analyses focused on the role(s) of twocis elements, TRE1 and TRE2 that are located at −129 to −149 and −102 to −120, respectively, on the α-MyHC promoter. Although the elements' ablation had differential effects on transgene expression, neither single mutation abolished transgene expression completely. Here, we show that mutating both elements results in a complete inactivation of the transgene in both ventricles and atria under euthyroid conditions. However, expression still can be detected in the hyperthyroid state, implying that, although the TRE1 and TRE2 elements are critical elements for high levels of α-MyHC transcriptionin vivo, other promoter sites can mediate at least some degree of transcriptional activation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01973758
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    pH and temperature optima for growth and sporulation in some common fungi from city waste (1995)
    Springer
    Mycoscience 36 (1995), S. 243-246 
    Details
    ISSN: 1618-2545
    Keywords: city waste ; fungal growth ; pH ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Relationships between the growth of certain fungi isolated from city waste and pH and temperature were examined by two methods. The tested isolates showed their maximum growth and sporulation at different pHs while temperature requirements were the same (28°C), except forHumicola grisea (43°C).Cladosporium herbarum andH. grisea showed double pH optima. The ranges of pH and temperature for sporulation were more limited than those for the vegetative growth. Although all the tested isolates showed wide tolerances to pH and temperature, the degree of tolerance varied with the isolates. A considerable change from the initial pH of the liquid medium was noted at the end of the experiment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02268565
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    The NADPH oxidase of phagocytic cells is an electron pump that alkalinises the phagocytic vacuole (1995)
    Springer
    Protoplasma 184 (1995), S. 86-103 
    Details
    ISSN: 1615-6102
    Keywords: Neutrophil ; Leukocyte ; NADPH ; Oxidase ; Microbicidal ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Phagocytic cells of the immune system contain an oxidase that is important for the killing and digestion of engulfed microbes. This is an electron transport chain that transfers electrons from NADPH in the cytosol to oxygen to form superoxide and hydrogen peroxide in the phagocytic vacuole. Absence or abnormality of this oxidase results in the syndrome of CGD, characterised by a profound predisposition to infection. The electron transport chain consists of a flavocytochrome b located in the plasma membrane and membrane of the specific granules. It is composed of a and b-subunits, with apparent molecular masses of 23 kDa and 76–92 kDa, respectively. The b-subunit is a member of the FNR family of reductases with FAD and NADPH binding sites. Based upon the crystal structure of FNR we have constructed a model of the more hydrophilic C terminal half of this b-subunit, which acts as a guide to the organisation of the molecule, and provides a template on which to map mutations in CGD. The location of the heme is uncertain. Electron transport is dependent upon an activation complex of cytosolic proteins including p40 phox , p47 phox , and p67 phox , and the small GTP binding protein, p21 rac . This oxidase system is important for the killing and digestion of bacteria and fungi. This might be accomplished in a number of ways. The oxidase produces superoxide and hydrogen which might be toxic themselves. The hydrogen peroxide can act as substrate for myeloperoxidase which can oxidise chloride and iodide to chlorine and iodine and their hypohalous acids. The proteins contained within the cytoplasmic granules are also very important in the killing process. These are neutral proteinases that require a neutral or slightly alkaline pH for optimal activity. The oxidase transports electrons, unaccompanied by protons, across the wall of the phagocytic vacuole, resulting in an elevation of the vacuolar pH, thereby optimising conditions for killing and digestion of engulfed organisms by these neutral proteinases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Vacuolar accumulation of acridine orange and neutral red in zygotic and somatic embryos of carrot (Daucus carota L.) (1995)
    Springer
    Protoplasma 188 (1995), S. 236-244 
    Details
    ISSN: 1615-6102
    Keywords: Acridine orange ; Carrot ; Embryogenesis ; Neutral red ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The accumulation of neutral red and acridine orange, to indicate differences in vacuolar pH, was studied during embryogenesis of carrot. Neutral red accumulated barely in proembryogenic masses, but was present conspicuously in globular-shaped somatic embryos. From the late globular to the torpedo-shaped stage, it was mainly found in the root side of the somatic embryo. Here, neutral red was predominantly present in large dark-red to purple stained vesicles. In the cotyledons neutral red was found in small orange vesicles. In zygotic embryos of carrot, the dye was uniformly distributed with no specific localization in organelles. During germination, however, neutral red accumulated mainly in regions in the root side and the hypocotyl of the germling. Acridine orange was dispersed erratically in proembryogenic masses with a great variety in intensity. It was quite obviously present in early stages of somatic embryogenesis and restricted to the root side in late globular to torpedo-shaped embryos. Confocal images revealed the vacuolar presence of the fluorescence and the predominant presence in the protoderm. During germination of zygotic embryos the signal changed from uniform to localized, with sharp borders between fluorescent and non-fluorescent regions. Two to three days after the beginning of germination, acridine orange accumulated preferentially in the root tip of the germling. Differences between somatic and zygotic embryos and similarities between somatic embryogenesis and zygotic embryo germination are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280375
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Assessment of the quality of pond sediment in aquaculture using simple, rapid techniques (1995)
    Springer
    Aquaculture international 3 (1995), S. 123-133 
    Details
    ISSN: 1573-143X
    Keywords: Ammonium ; Coastal ponds ; Hydrogen sulphide ; pH ; Redox potential ; Sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Aquaculture ponds receive inputs of organic matter such as uneaten feed, fertilizer and faeces. Analytical methods for four parameters are described to assess the sediment quality. These parameters are redox potential, pH, the hydrogen sulphide activity potential (pH2S) and soluble ammonium nitrogen. The techniques are simple, rapid, and are practical on site. Ranges encountered are given and ‘safe’ ranges suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00117879
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Physiological characteristics and regulation mechanisms of the H+ pumps in the plasma membrane and tonoplast of characean cells (1995)
    Springer
    Journal of plant research 108 (1995), S. 249-256 
    Details
    ISSN: 1618-0860
    Keywords: Characeae ; H+ pump ; pH ; Pi ; Plasma membrane ; Tonoplast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The relationship between the physiological characteristics and changes in the activities of H+ pumps of the plasma membrane and tonoplast of characean cells is discussed. The large size of the characean internodal cells allows us to perform various experimental operations. The intracellular perfusion technique developed by Tazawaet al. (1976) is a powerful tool for analyzing the characteristics and control mechanisms of the H+ pumps (Tazawa and Shimmen 1987, Tazawaet al. 1987, Shimmenet al. 1994) Respiration-dependent changes in the activity of the plasma membrane H+ pump are explained by changes in the supply of energy substrate. Photosynthesis-dependent changes in activities of both the plasma membrane and the tonoplast H+ pumps are explained in terms of changes in the level of inorganic phosphate in the cytoplasm. Cytoplasmic and vacuolar pHs are suggested to be controlling factors forin vivo activities of the H+ pumps. Furthermore, the membrane potential and various ions are considered to bein vivo factors that regulate the activities of the H+ pumps.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02344350
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Solution pH modifies the response of Norway spruce seedlings to aluminium (1995)
    Springer
    Plant and soil 171 (1995), S. 175-178 
    Details
    ISSN: 1573-5036
    Keywords: aluminium ; mycorrhizae ; pH ; root growth ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Norway spruce (Picea abies) was exposed to nutrient solutions containing a range of aluminium (Al) concentrations at several pH levels (3.2, 4 and 5). Root growth was reduced by 100 µM and 400 µM Al at pH 4 and 5, but at pH 3.2 only by 400 µM Al. The Al content of the roots increased with increasing pH. The Al content of the roots was higher at the root tips than at the older root parts at all pH values. Using X-ray microanalysis it could be shown that higher levels of Al at increased pH were mainly due to increased Al contents in root cortex cell walls. In seedlings, mycorrhizal with Pisolithus tinctorius or Lactarius rufus, the Al concentration of cortex cell walls was higher when nitrate (NO3) rather than ammonium (NH4) was the nitrogen (N) source.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00009583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Relationship between soil solution aluminium and low molecular weight organic acids in a conservation cropping system (1995)
    Springer
    Plant and soil 171 (1995), S. 193-197 
    Details
    ISSN: 1573-5036
    Keywords: aluminium ; organic acids ; pH ; stubble burnt ; stubble retained
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Soil solution and solid phase analyses were compared for stubble standing and stubble burnt systems on an acid, acidified and limed Alfisol in north-eastern Victoria. Exchangeable (1 M KCl) aluminium (Al), soil solution total and monomeric Al, pH (water) and soil solution pH were measured to identify any differences in soil acidification between the stubble burnt and the stubble standing treatments. All measures of Al increased with soil depth down to 10 cm in all stubble treatments and decreased in the 10–20 cm soil depth with the exception of lime treatments. Concentrations of low molecular weight organic acids in the soil solution were determined by high pressure liquid chromatography (HPLC). Aromatic and aliphatic acids were distributed throughout the soil depth (0–20 cm) for the stubble standing treatments but were confined to the 0–5 cm soil depth for the stubble burnt treatment. In this short term field trial (2 years for stubble management), the data suggest that the conventional practice of stubble burning was more acidifying than the soil conservation practice of stubble standing, over the 0–20 cm soil depth for the lime (6 t ha-1) treatments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00009587
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Growth, radicle and root hair development ofDeschampsia flexuosa (L.) Trin. seedlings in relation to soil acidity (1995)
    Springer
    Plant and soil 175 (1995), S. 125-132 
    Details
    ISSN: 1573-5036
    Keywords: distribution ; germination ; H+ ; pH ; soil solution ; toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Deschampsia flexuosa (L.) Trin. is an abundant grass species in the ground flora of acidic beech forests in southern Sweden. Generally, the species is restricted to a limited soil pH range (pH 4–5). The main objective was to study the influence of different soil acidities on germination, initial root development and on the growth of the species. The experiments were carried out under controlled conditions and designed to simulate the physico-chemical conditions present in the field. By using forest soils within the pH range 4.0 to 8.3 and artificial variation in pH (3.2 to 7.6) of soil-water extracts, it was possible to evaluate the influence of soil reaction and the H+ per se. In all experiments seeds have been used. Germination was significantly delayed in the very acid soil (pH 4.0) in comparison to the germination in soils within the pH range (4.4 to 6.4). Soil substances, other than the H+, might be responsible for this delay in germination, whereas development of the radicle was markedly affected by increasing H+ concentrations. Especially the development of root hairs was sensitive to H+ and was significantly reduced at a pH〈-3.8. By increasing soil acidity the injury symptoms, including curling and discolouring, became more intense and at the highest acidity (pH 3.2) the radicles appeared brown, stunted and the root hairs were lacking. Most favourable growth was obtained at pH 4.4 and 5.0. Soil pH levels above and below this range limited both shoot and root growth. The results showed very good correspondence with observations made in Beech forest soils in southern Sweden, where the species was growing in soils within the pH range 3.9 to 5.1 with a peak growth at pH 4.3. This study shows that in soils at pH≤3.8, the poor development of the radicle may be crucial in the establishment ofDeschampsia flexuosa. Root hair development was more sensitive to soil acidity than radicle elongation. Germination was delayed in very acid Beech forest soils but other factors than the H-ion per se may be responsible for this delay.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02413017
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Nitrogen mineralization and potential nitrification at different depths in acid forest soils (1995)
    Springer
    Plant and soil 168-169 (1995), S. 55-65 
    Details
    ISSN: 1573-5036
    Keywords: acidity ; autotro[hic nitrifiers ; N mineralization ; nitrification ; pH ; soil horizon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Soil samples were collected from the litter, humus and five mineral soil layers to a depth of 50 cm in acid, but highly productive, Norway spruce forests in S Sweden and E Denmark for determination of net N mineralization and potential nitrification. The samples were sieved while still fresh and incubated at a constant temperature (15°C) and soil moisture for 74–117 days with periodic subsamplings. Net N mineralization rates, expressed per g organic matter or per g of total N, decreased with increasing depth. Net N mineralization in the ten soils studied ranged from 35 to 105 kg N ha- yr-1, of which the organic horizons contributed 32–74%. Nitrate formation patterns were variable. Almost no nitrification could be detected at pH (H2O) values lower than 4.0. Nitrate was formed in humus layers with pH values of 4.0–4.5, but the nitrification was never complete. By contrast, the nitrification was almost complete at a depth of 10–50 cm, where the pH (H2O) was 4.1–4.5. Addition of CaCO3 stimulated nitrification in the humus layer, indicating the presence of acid-sensitive nitrifiers, while nitrification in the mineral soil was sometimes sthnulated and sometimes inhibited by the addition of CaCO3. Tests with the acetylene block method showed that nitrification, when it occurred, was autotrophic in the humus layer but less easy to characterize in the mineral soil. Thus, further studies are needed to characterize the nitrifier organisms and identify the factors regulating the activity of these organisms. Actual nitrification rates in the field could not be determined, but our findings showed that the B horizon in acid forest soils has a great potential for nitrification. Because N deposition does not appear to decrease in Scandinavian forests, we conclude that an ammonium surplus in the forest floor followed by a downward transport of ammonium to the nitrifying subsoil can increase the risk of nitrate leaching in the future.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029313
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Soil changes in different age classes of Norway spruce (Picea abies (L.) Karst.) on afforested farmland (1995)
    Springer
    Plant and soil 168-169 (1995), S. 103-110 
    Details
    ISSN: 1573-5036
    Keywords: afforestation ; carbon ; cation exchange capacity ; Norway spruce ; pH ; soil changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The aim of this study was to test the hypothesis that afforestation changes the content and distribution of soil organic carbon, nutrients and pH in the A-horizon of land previously used in agriculture, and that such soil changes depend on stand development. The investigation was evaluated as a completely randomised design with three treatments representing different age classes of trees: 20 years (Y20), 40 years (Y40) and 55 years (Y55). Eighteen trial plots, six per treatment, were established in plantations of Picea abies (L.) Karst. on soils of similar texture and mineralogy. Tree volume was 220 m3 ha-1 in Y20, 400 in Y40 and 440 m3 ha-1 in Y55. Concentrations of carbon (C) and nitrogen (N) were significantly higher in the uppermost part of the soil in the older stands Y40 and Y55 than in Y20. The total amount of organic C in the litter layer plus the top 15 cm of the soil differed between age classes, with Y40 and Y55 having the largest amounts. A reference layer (15–20 cm) was used in calculating the amount of soil C that had accumulated in the horizon since afforestation, being about 10 tonnes ha-1 of C in Y20 and 19 tonnes ha-1 in Y40 and Y55. Cation exchange capacity (CEC) and base saturation (BS) was higher in the older stands. Carbon contents and CEC were strongly correlated. In Y40 and Y55, pH was significantly lower than in Y20 in the lower part of the soil horizon. There was a general decrease with depth of C, N, CEC, K+ and Mg2+ in the soil horizon. BS, Ca2+, Na+ and pH showed a somewhat different pattern of distribution, with deceasing values in the upper part of the soil horizon and increasing values in the lower part of the soil horizon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029319
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Is the Ca:Al ratio superior to pH, Ca or Al concentrations of soils in accounting for the distribution of plants in deciduous forest? (1995)
    Springer
    Plant and soil 177 (1995), S. 21-31 
    Details
    ISSN: 1573-5036
    Keywords: Ca:Al ratio ; exchangeable Ca and Al ; forest plant distribution ; pH ; soil solution Ca and Al
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The distributions of vascular plants in south Swedish deciduous forests were related to exchangeable (exc) and soil solution concentrations of H+ (pH), Ca, Al and the Ca:Al ratios within these fractions. Topsoils (0–5 cm) of 172 sites with a pHKCl of 3.2–3.9 (corresponding to 3.7–4.4 in soil solution) were used. In the soil solution both total Alt and quickly reacting Alr were determined. Exchangeable concentrations were generally well related to plant distributions, the highest correlation coefficients usually being given by pHKCl〉Caexc〉Alexc.〉(Ca:Al)exc. The (Ca:Al)exc ratio was clearly inferior. Out of the soil solution variables studied, Ca concentration, followed by pH, was best correlated with plant distributions, Alt, Alr, and the Ca:Al ratios having similar and lower coefficients. It is concluded that the use of Ca:Al ratios as a general measure of Al toxicity in controlling plant distributions is rather problematic. It seems difficult to apply evidence for Ca-Al interactions from solution culture experiments to field conditions when measured as exchangeable or soil solution concentrations of the soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010334
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Reversibility of damages to forest floor plants by episodes of elevated hydrogen- and aluminium-ion concentrations in the soil solution (1995)
    Springer
    Plant and soil 176 (1995), S. 297-305 
    Details
    ISSN: 1573-5036
    Keywords: aluminium ; episodes ; flowing solution culture ; pH ; reversibility, toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Herbs and grasses may episodically be exposed to elevated concentrations of potentially toxic elements as H+ and Al3+ due to considerable temporal variability in the chemical composition of soil solutions in the uppermost layer of the soil profile. Greenhouse experiments were performed to test the effect of episodes of different length (1 and 2 weeks) and concentrations of H+ and Al3+ (pH 3.8, 4.0, 4.2 and 4.5; 0, 20 and 70 μM Al) on root and shoot growth, designed to elucidiate the reversibility of growth inhibition. Three forest floor species were studied-Galium odoratum and Lamium galeobdolon, having similar pH distribution ranges in the field and Poa nemoralis which also occurs at slightly lower pH. The plants were grown for 5 weeks (episode and recovering time) in a synthetic soil solution in a flowing solution system without recirculation. The species reacted in three different ways. Galium odoratum was the most sensitive species and seemed to be irreversibly damaged (ceased growth) by 2 week episodes of pH≤4.0 and Al≥20 μM at pH≤4.2. Lamium galeobdolon was about equally sensitive during the episodes but it had a much greater ability to recover. Poa nemoralis was rather insensitive to the episode treatments tested. It is concluded that episodes of elevated H+ and Al3+ concentrations may be decisive for plant performance. It is therefore important to consider the extreme environmental conditions which plants may be exposed to in the field, in addition to long-term averages of e.g. soil solution concentration of potentially toxic elements, when studying species distribution and performance in relation to soil chemical properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00011794
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Monitoring of haploid maize cell suspension culture conditions in bioreactors (1995)
    Springer
    Plant cell, tissue and organ culture 43 (1995), S. 123-126 
    Details
    ISSN: 1573-5044
    Keywords: bioreactor ; dissolved oxygen ; haploid cell suspension ; pH ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Maize (Zea mays L.) haploid cells were cultivated in a 1500 ml aerated and stirred batch bioreactor using modified BM medium. Cell growth was highly affected by pH and dissolved oxygen, and we observed two fairly distinct growth phases. During the first two days after inoculation at pH 5.8, oxygen consumption was high and the cells lowered the pH to a value around 4.3. After this period the pH stabilized at 4.5 and the dissolved oxygen reached a steady level. Decreasing dissolved oxygen concentration leads to lower growth rate and to higher pH. Both events mean stress conditions for the cell culture and probably result in increased genetic variability, and the loss of regeneration capacity. The stress condition during the adaptation phase can be eliminated by decreasing the pH of the medium to 4.7 before inoculation and by keeping dissolved oxygen above 40%. These conditions provide prolonged exponential growth dynamics and the cell suspensions could be the basis of large scale cultures also.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00052166
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Glycine decarboxylase: Protein chemistry and molecular biology of the major protein in leaf mitochondria (1995)
    Springer
    Journal of bioenergetics and biomembranes 27 (1995), S. 407-414 
    Details
    ISSN: 1573-6881
    Keywords: Glycine decarboxylase ; mitochondria ; photorespiration ; gene expression ; light control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract The four component proteins of the glycine decarboxylase multienzyme complex (the P-, H-, T-, and L-proteins) comprise over one-third of the soluble proteins in mitochondria isolated from the leaves of C3 plants. Together with serine hydroxymethyltransferase, glycine decarboxylase converts glycine to serine and is the site of photorespiratory CO2 and NH3 release. The component proteins of the complex are encoded on nuclear genes with N-terminal presequences that target them to the mitochondria. The isolated complex readily dissociates into its component proteins and reassociates into the intact complexin vitro. Because of the intimate association between photosynthesis and photorespiration, the proteins of the complex are present at higher levels in leaves in the light. The expression of these genes is controlled at the transcriptional level and the kinetics of expression are closely related to those of the small subunit of Rubisco. Deletion analysis of fusions between the promoter of the H-protein of the complex and the reporter gene β-glucuronidase in transgenic tobacco has identified a region responsible for the tissue specificity and light dependence of gene expression. Gel shift experiments show that a nuclear protein in leaves binds to this region. Glycine decarboxylase has proven to be an excellent system for studying problems in plant biochemistry ranging from protein-protein interactions to control of gene expression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02110003
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Regulation of gonadotropin-releasing hormone (GnRH) gene expression in hypothalamic neuronal cells (1995)
    Springer
    Cellular and molecular neurobiology 15 (1995), S. 79-88 
    Details
    ISSN: 1573-6830
    Keywords: gonadotropin-releasing hormone ; gene expression ; tissue-specific expression ; steroid hormone ; peptide hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Gonadotropin-releasing hormone (GnRH) is the hypothalamic releasing factor that controls pituitary gonadotropin subunit gene expression and indirectly gametogenesis and steroidogenesis from the gonad, which results in reproductive competence. 2. GnRH is synthesized in only about 1000 neurons in the hypothalamus and released in an episodic fashion down the median eminence to regulate gonadotropin biosynthesis. 3. Although much is known about the secretory dynamics of GnRH release, little is known about the pretranslational control of GnRH biosynthesis due to lack of appropriate model systems. The recent availability of immortalized neuronal cell lines that produce GnRH allows investigators for the first time to begin to dissect the factors that directly regulate GnRH gene expression. 4. This article reviews the current state of knowledge concerning the mechanisms that direct tissue-specific and peptide hormone control of GnRH biosynthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02069559
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    The freshwater planarian Dugesia (G.) tigrina contains a great diversity of homeobox genes (1995)
    Springer
    Hydrobiologia 305 (1995), S. 269-275 
    Details
    ISSN: 1573-5117
    Keywords: Turbellaria ; Dugesia ; homeobox ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To identify potential pattern control and cell determination and/or differentiation genes in the freshwater planarian Dugesial (G.) tigrina, we searched for homeobox genes of different types in the genome of this primitive metazoan. We applied two basic approaches: 1) Screening the cDNA library with degenerate oligonucleotides corresponding to the most conserved amino acid sequence from helix-3 of the homeodomain of each family; and 2) PCR amplification of genomic DNA or cDNA, using two sets of degenerated oligonucleotides corresponding to helices 1 and 3 of the homeodomain or two specific domains of the POU family. Using the first strategy we have identified and characterized two tissue-specific cell determination and/or differentiation NK-type homeobox genes. Using the second strategy we have identified several homeobox genes that belong to the HOM/Hox, paired (prd) or POU families.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00036404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Molecular biology of extremophiles (1995)
    Springer
    World journal of microbiology and biotechnology 11 (1995), S. 71-84 
    Details
    ISSN: 1573-0972
    Keywords: Archaea ; gene expression ; genetics ; replication ; thermophile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The molecular biology of extremophiles has recently attracted much interest, both in terms of cell adaptation to extreme environmental conditions and the development of manipulative genetic techniques. Although molecular genetic techniques have been successfully applied to halophiles and methanogens, their use with hyperthermophiles is limited by the extreme growth conditions that these organisms require. Much information on the thermophilic Archaea, has been obtained by studying the key enzymes involved in fundamental cell processes, such as transcription and replication, and by the cloning, sequence comparison and heterologous expression of structural genes. The development of viral vectors and systems for transformation, mutant production and screening will permit increased genetic manipulation of these organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339137
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Adsorption of codeine on hydrophilic silica and silica surface modified by hydrophobic groups in the presence of electrolytes (1995)
    Springer
    Colloid & polymer science 273 (1995), S. 687-692 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption ; codeine ; surface modified ; silica ; alkyl group ; electrolyte ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The adsorption of codeine from aqueous solution onto colloidal silica and silica surface-modified with chemiadsorbed octadecyl dimethyl silane (ODDMS) or dimethyl silane (DMS) groups was studied in the presence of neutral electrolytes at different pH values. From codeine-hydrochloride solutions codeine cations are strongly bound to negatively charged silica surfaces. Inorganic salts (NaCl, NaNO3) reduce the adsorption of the organic cation. On silica modified by ODDMS (10% of surface silanol groups are occupied), codeine cations are adsorbed to a higher extent at pH 6, while at pH 8 the adsorbed amounts are lower than on the bare silica surface. Neutral electrolytes reduce codeine adsorption on the ODDMS modified silica. On the hydrophobic silica, completely covered by DMS groups, codeine adsorption is considerably lower than on the bare silica, but neutral salts increase the adsorption. The adsorption of codeine is compared with the adsorption of aggregating surfactant ions. Common and different features of their interactions with silica surfaces are outlined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00652262
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Genes for β-lactam antibiotic biosynthesis (1995)
    Springer
    Antonie van Leeuwenhoek 67 (1995), S. 181-200 
    Details
    ISSN: 1572-9699
    Keywords: β-lactam antobiotics ; biosynthetic enzymes ; penicillin ; cephalosporin ; cephamycin ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genespcbAB,pcbC andpenDE encoding enzymes involved in the biosynthesis of penicillin have been cloned fromPenicillium chrysogenum andAspergillus nidulans. They are clustered in chromosome I (10.4 Mb) ofP. chrysogenum, but they are located in chromosome II ofPenicillium notatum (9.6 Mb) and in chromosome VI (3.0 Mb) ofA. nidulans. Expression studies have shown that each gene is expressed as a single transcript from separate promoters. Enzyme regulation studies and gene expression analysis have provided useful information to understand the control of gene expression leading to overexpression of the genes involved in penicillin biosynthesis. Cephalosporin genes have been studied inCephalosporium acremonium and also in cephalosporin-producing bacteria. InC. acremonium the genes involved in cephalosporin biosynthesis are separated in at least two clusters. Cluster I (pcbAB-pcbC) encodes the first two enzymes of the cephalosporin pathway which are very similar to those involved in penicillin biosynthesis. Cluster II (cefEF-cefG), encodes the last three enzymatic activities of the cephalosporin pathway. It is unknown, at this time, if thecefD gene encoding isopenicillin epimerase is linked to any of the two clusters. In cephamycin producing bacteria the genes encoding the entire biosynthetic pathway are located in a single cluster extending for about 30 kb inNocardia lactamdurans, and inStreptomyces clavuligerus. The cephamycin clusters ofN. lactamdurans andS. clavuligerus include a genelat which encodes lysine-6-aminotransferase an enzyme involved in formation of the precursor α-aminoadipic acid. TheN. lactamdurans cephamycin cluster includes, in addition, a β-lactamase (bla) gene, a penicillin binding protein (pbp), and a transmembrane protein gene (cmcT) that is probably involved in secretion of the cephamycin. Little is known however about the mechanism of control of gene expression in the different β-lactam producers. The availability of most of the structural genes provides a good basis for further studies on gene expression. This knowledge should lead in the next decade to a rational design of strain improvement procedures. The origin and evolution of β-lactam genes is intriguing since their nucleotide sequences are extremely conserved despite their restricted distribution in the microbial world.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00871213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Analysis of flagellin gene expression in flagellar phase variants ofCampylobacter jejuni 81116 (1995)
    Springer
    Antonie van Leeuwenhoek 67 (1995), S. 377-383 
    Details
    ISSN: 1572-9699
    Keywords: Campylobacter jejuni ; flagella ; flagellin genes ; flaA ; flaB ; phase variation ; gene expression ; sigma 28 ; sigma 54 ; repressor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Flagella production inCampylobacter jejuni 81116 is subject to phase variation; the bacterium is able to switch its flagellum synthesis, and thereby its motility, on and off. Under standard laboratory growth conditions flagellar phase variants can be maintained as stable, pure cultures. We found conditions that efficiently induced a phase shiftin vitro. TheflaA gene but not theflaB gene is subject to the on and off switch. Minor amounts of FlaB are still present in aflagellate cells. We previously showed that flagellin gene expression in phase variants was regulated at the transcriptional level. Here, sequence data prove that abolishment offlaA transcription is not caused by DNA rearrangements or mutations within the flagellin locus. SinceflaA is preceeded by a typical σ28 promoter aC. jejuni σ28 homolog could play a role in regulation offlaA gene expression but such a gene or protein could not be detected. However,in vitro transcription could be detected using σ28-holoenzyme preparations fromBacillus subtilis. Possible regulatory mechanisms that may control flagellar phase variation in Campylobacter are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872938
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    pH sensitivity of the redox state of cytochrome b559 may regulate its function as a protectant against donor and acceptor side photoinhibition (1995)
    Springer
    Photosynthesis research 46 (1995), S. 193-202 
    Details
    ISSN: 1573-5079
    Keywords: cytochrome b 559 ; electron transport ; pH ; pheophytin ; photosynthesis ; Photosystem II ; reaction center ; redox potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A series of experiments have been conducted with isolated reaction centers of photosystem two (PS II) with the aim to elucidate the functional role of cytochrome (Cyt b 559). At pH 6.5 it was found that Cyt b 559 was reversibly photoreduced by red actinic light when Mn2+ was present as an electron donor while at pH 8.5 a photo-oxidation was observed under the same lighting conditions, which was dark reversible in the presence of hydroquinone. These pH dependent light induced changes were measured under anaerobic conditions and correlated with changes in the relative levels of high (HP) and low (LP) potential forms of the cytochrome. At pH 6.5 the cytochrome was mainly in its LP form while at pH 8.5 a significant proportion was converted to the HP form as detected by dark titrations with hydroquinone. This pH dependent difference in the levels of HP and LP Cyt b 559 was also detected when bright white light was used to monitor the level of the LP form using a novel reaction involving direct electron donation from the flavin of glucose oxidase (present in the medium and used together with glucose and catalase as an oxygen trap). The results suggest that PS II directly oxidises and reduces the HP and LP forms, respectively and that the extent of these photo-reactions is dependent on the relative levels of the two forms, which are in turn governed by the pH. This conclusion is interpreted in terms of the model presented previously (Barber J and De Las Rivas J (1993) Proc Natl Acad Sci USA 90: 10942–10946) whereby the pH induced effect is considered as a possible mechanism by which interconversion of LP and HP forms of Cyt b 559 is achieved. In agreement with this was the finding that as the extent of photo-oxidisable HPCyt b 559 increases, with increasing pH, the rate of irreversible photo-oxidation of β-carotene decreases, a result expected if the HP form protects against donor side photoinhibition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020430
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...