ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Saccharomyces cerevisiae  (43)
  • phosphorus  (42)
  • maize  (36)
  • gene expression
  • Springer  (142)
  • 1990-1994  (142)
  • 1955-1959
  • 1990  (142)
Collection
Keywords
Publisher
Years
  • 1990-1994  (142)
  • 1955-1959
Year
  • 1
    ISSN: 1420-9071
    Keywords: Aldehyde dehydrogenase ; developmental changes ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous reports suggested that the major cytosolic aldehyde dehydrogenase (ALDH1) was present in fetal and infant livers, but the major mitochondrial isozyme (ALDH2) was absent or severely diminished. Re-examination by means of starch gel electrophoresis followed by enzyme activity staining, and by means of dot blot immuno-hybridization of liver samples with known genotypes of theALDH 2 locus, indicated that bothALDH 1 andALDH 2 genes are expressed in fetal and infant livers. In addition, ALDH4 isozyme was also observed. The results imply that a fetus with the ‘usual’ homozygousALDH 2 1 /ALDH 2 1 genotype, but not one with the atypicalALDH 2 1 /ALDH 2 2 orALDH 2 2 /ALDH 2 2 , is capable of detoxifying acetaldehyde transferred from the mother.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Aquatic sciences 52 (1990), S. 199-220 
    ISSN: 1420-9055
    Keywords: Eutrophication ; lake management ; phosphorus ; ecosystem ; chlorophyll-a ; mathematical modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We compare results of a new model for predicting the short term inter annual changes in chlorophyll-a (chl-a) in lakes after reductions in total phosphorus (TP) to predictions made by least squares regression models. In the new method, slopes of chl-a/TP graphs (both axes in mg · m−3) are depicted in frequency diagrams and used to extract information on the expected, short term chl-a/TP response. The short term response for nine shallow (〈 10 m deep) and nutrient rich lakes to changes in TP was found to be: Chl-a = 0.49 · TP + 17.3, and for nine deep, P-limited lakes: Chl-a = 0.08 · TP + 3.5. If the TP-reduction is known to be greater than 10 mg · m−3, the expected slope increases to 0.58 for shallow lakes and to 0.26 for deep lakes. The slope, 0.58, is 8% lower than the slope for the long term response calculated by regression for the shallow lakes. For deep lakes the slope, 0.26, is 2 to 3 times higher than that calculated by regression, indicating that reductions in TP for deep lakes give greater effects than least squares regression equations suggest. We have also calculated the reduction in TP which will give about 80% probability that a reduction in chl-a will be observed next year. For shallow, P-limited lakes this reduction is about 30 mg · m−3 (5% of average initial in-lake TP concentration), and for deep lakes about 14 mg · m−3 (35% of average initial in-lake TP concentration).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Aquatic sciences 52 (1990), S. 256-268 
    ISSN: 1420-9055
    Keywords: Vertical mixing ; stratification ; phosphorus ; Lake Constance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Depth variable vertical eddy diffusion coefficients for heat (K z) were calculated from continuously measured temperature profiles in Überlinger See (western part of Lake Constance). The temperatures were averaged over vertical intervals of 10 m yielding 14 discrete values (maximum depth of Überlinger See: 147 m). A linear fit from 10 June to 29 September 1987 was used to smooth the significant temperature fluctuations caused by internal seiches of Lake Constance. Assuming horizontal homogeneity for the smoothed data the Gradient-Flux-Method was applied to compute vertical diffusion coefficientsK z at different depths using the depth variable volumes and surfaces of the 14 layers. The resulting mean diffusion coefficients for the period from June to September are 0.04 cm2/s near the thermocline and up to 0.8 cm2/s in deeper strata (accuracy: ± 50%). It is shown that horizontal mixing between Überlinger See and Obersee (main lake) alters the computation ofK z by less than 50%. A relationship betweenK z and stability (Brunt-Väisälä) frequencyN is found which corresponds well to the theory of internal wave induced turbulence. Combining the diffusion coefficients with measured phosphorus profiles, a phosphorus flux from the hypolimnion to the epilimnion of (0.7 ± 0.4) mg P m−2 d−1 was calculated, corresponding to about 20% of the average external loading per area of Lake Constance in 1986.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 55 (1990), S. 285-294 
    ISSN: 1570-7458
    Keywords: Graminella nigrifrons ; maize ; oats ; johnsongrass ; development ; fecundity ; host suitability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La dynamique des populations (durée de développement de l'œuf à l'adulte, poids et taille des adultes, fécondité) de G. nigrifrons Forbes (Homop. Cicadellidae) a été étudiée au laboratoire à 5 températures sur plantules de maïs (Zea mays L.), avoine (Avena sativa L.) et sorgho vivace (Shorgum halepense (L.) Pers.). Sur les 3 plantes, les mâles se développent en moyenne 1,2 j plus vite que les femelles. Les relations entre vitesse de développement et température ont été déterminées en utilisant à la fois un modèle linéaire et le modèle biophysique à 2 paramètres de Sharpe & DeMichele (1977). Les températures plus basses donnent des adultes des 2 sexes plus gros et plus lourds. Moins de G. nigrifrons se sont développés sur la graminée vivace que sur les 2 graminées annuelles à la température la plus élevée (30°C), tandis qu'à la température la plus basse (18°C) moins de cicadelles se sont développées sur les graminées annuelles. La température semble jouer un rôle significatif en déterminant l'adéquation des plantes comme hôtes convenant au développement de G. nigrifrons. Le potentiel de ponte de cette cicadelle avait été sous-estimé par les étudies précédentes.
    Notes: Abstract Population dynamics of the blackfaced leafhopper, Graminella nigrifrons (Forbes) (Homoptera: Cicadellidae), was studied at five temperatures (18, 21, 24, 27, & 30°C) in the laboratory on seedling maize (Zea mays L.), oats (Avena sativa L.), and the perennial johnsongrass (Sorghum halepense (L.) Pers.). Effects of temperature and host plant on egg to adult mean development time, adult size and weight, and fecundity were determined. Leafhoppers on all three hosts developed fastest at the highest temperature tested (21.3 days), and slowest at the lowest temperature tested (73.2 days). The duration from first to last adult eclosion was shortest at 30°C, (11.5 days) and longest at 18°C (43 days). The sex ratio of males to females did not differ from 1:1, but males developed an average of 1.2 days faster than females on all three hosts. Mean percent development/day ranged from 1.4% at 18°C to 4.7% at 30°C. The relationship of this development rate and temperature was determined using both a linear model and a variable parameter biophysical model. Based on these models, the developmental threshold is estimated at 12–15°C. The lowest temperature yielded larger and heavier adults (312 μg, dry weight) than did the highest temperature (225 μg). Fewer leafhoppers developed on the perennial than the annuals at 30°C and fewer on the annuals than the perennial at 18°C. Our results suggest that early in the season johnsongrass and perhaps other perennials are the superior developmental hosts for this leafhopper, whereas in midsummer when temperatures are highest, annuals are the better hosts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0983
    Keywords: 2-oxoglutarate dehydrogenase ; Saccharomyces cerevisiae ; rad52-mediated chromosome loss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ogd1 mutants of Saccharomyces cerevisiae are deficient in mitochondrial 2-oxoglutarate dehydrogenase activity; they cannot grow on glycerol and produce an increased amount of organic acids during growth on glucose as substrate. Using gamma ray-induced rad52-mediated chromosome loss the ogd1 mutation can be assigned to chromosome IX. Tetrad analysis of crosses between ogd1 and other markers on chromosome IX revealed that the OGD1 gene maps on the left arm of this chromosome 1.9 cM from his5.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Orotate phosphoribosyl transferase ; Nucleotide sequence-5-phosphoribosyl 1-pyrophosphate (5PRPP)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Orotate phosphoribosyl transferase (OPRTase) catalyses the transformation of orotate to OMP in the pyrimidine pathway. In the yeast Saccharomyces cerevisiae, the URA5 gene is known to encode this enzyme activity. In this paper we present the cloning and sequencing of a yeast gene, named URA10, encoding a second OPRTase enzyme. Comparison of the predicted amino acid sequences between URA5 and URA10 genes shows more than 75% similarity. These sequences have also been compared to those of Escherichia coli, Podospora anserina, Sordaria macrospora and Dictyostelium discoideum. Remarkable similarities in the primary structure of these proteins have been found. Gene disruption experiments revealed that URA10 gene expression is responsible for the leaky phenotype of a ura5 mutant. Assays of OPRTase activity in extracts from ura5 and ura10 mutants indicate that the URA10 product contributes only 20% of the total activity found in wild type cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Mutants ; Farnesyl diphosphate synthetase ; Ergosterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two yeast mutant strains auxotrophic for ergosterol and blocked in farnesyl diphosphate synthetase (EC 2.5.1.1) were isolated. Genetic analysis has shown that these mutant strains carry additional mutations in the ergosterol pathway besides erg20-1 and erg20-2 which affect FPP synthetase. The novel feature of these mutants is their ability to excrete prenyl alcohols (farnesol and geraniol). As geraniol is toxic for yeast cells, the above leaky mutations in FPP synthetase have to be associated with others in the sterol pathway, in order to slow down geraniol synthesis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0983
    Keywords: Glucose oxidase ; Aspergillus ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We report the cloning of the Aspergillus niger glucose oxidase gene and its use to elevate glucose oxidase productivity in A. niger by increasing the gene dosage. In addition, the gene has been introduced into A. nidulans where it provides the novel capacity to produce glucose oxidase. A plasmid, in which DNA encoding the mature form of glucose oxidase was preceded by a Saccharomyces cerevisiae secretion signal, effected high-level production of extracellular glucose oxidase in this yeast.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 18 (1990), S. 401-403 
    ISSN: 1432-0983
    Keywords: Baking yeast ; Saccharomyces cerevisiae ; Dough leavening ; Benomyl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To investigate the leavening ability of yeast in dough, chromosome loss was induced by benomyl treatment in YOY1037, a diploid between a baking strain and a laboratory strain, and its effect on the leavening ability was studied. When benomyl-treated cells were spread on plates with a dye indicator for ploidy, about 20% of the visible colonies were stained dark blue or dark purple; the rest stained pale blue, similar to the diploid YOY1037. Strains showing the MATα phenotype, and non-galactose fermenting strains, apparently having lost particular chromosomes, were observed only in those with darkcoloured colonies. Strains with dark-coloured colonies showed a wider range of leavening ability than did those with pale-coloured colonies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0983
    Keywords: Xylitol dehydrogenase gene ; Pichia stipitis ; Saccharomyces cerevisiae ; Xylose utilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A P. stipitis cDNA library in λgt11 was screened using antisera against P. stipitis xylose reductase and xylitol dehydrogenase, respectively. The resulting cDNA clones served as probes for screening a P. stipitis genomic library. The genomic XYL2 gene was isolated and the nucleotide sequence of the 1089 bp structural gene, and of adjacent non-coding regions, was determined. The XYL2 open-reading frame codes for a protein of 363 amino acids with a predicted molecular mass of 38.5 kDa. The XYL2 gene is actively expressed in S. cerevisiae transformants. S. cerevisiae cells transformed with a plasmid, pRD1, containing both the xylose reductase gene (XYL1) and the xylitol dehydrogenase gene (XYL2), were able to grow on xylose as a sole carbon source. In contrast to aerobic glucose metabolism, S. cerevisiae XYL1-XYL2 transformants utilize xylose almost entirely oxidatively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 1432-0983
    Keywords: Mutagen hyper-resistance ; Nitrogen mustard ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A screening of haploid yeast strains for enhanced resistance to nitrogen mustard (HN2) yielded a recessive mutant allele, hnm1, that conferred hyper-resistance (HYR) to HN2. Diploids, homo- or heterozygous for the HNM1 locus, exhibit normal wild-type like resistance while homozygosity for hnm1 leads to the phenotype HYR to HN2. The hnm1 mutation could be found in yeast strains proficient or deficient in different DNA repair systems. In these mostly HN2-sensitive haploid repair-deficient mutants, hnm1 acted as a partial suppressor of HN2 sensitivity. All isolated recessive mutations conferring hyper-resistance belonged to a single complementations group. The HYR to HN2 phenotype was maximally expressed in growing cells and was associated with reduced mutability by HN2. HNM1 most probably controls uptake of HN2 which would be impaired in the hnm1 mutants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; G418 resistance ; Gene cartridges ; Heterologous Gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Coding sequence cartridges for aminoglycoside phosphotransferase (APT) were isolated from bacterial transposon Tn903. When incorporated into a heterologous gene construction utilising the PGK1 promoter and terminator, the heterologous APT gene provided a G418-resistance determinant that functioned efficiently as a dominant marker for yeast in both multiple- and single-copy. Transformant colonies on selective medium appeared rapidly, within 36–48 h, and growth rate of the transformed cells was normal. A simple and highly sensitive radiolabelling assay for APT enzyme activity was developed for use with crude cell protein extracts. Enzyme activity units were equated to the amount of APT protein present in the cells, and the APT protein was shown to be stable in yeast. Heterologous APT expression was 130-fold reduced compared with homologous PGK1. This resulted from an estimated two-fold decrease in mRNA level and a 65-fold decrease in translation efficiency. The latter was unaffected by AUG sequence context change, but corresponded with a high frequency of minor codons in the APT-coding sequence. APT can be used as a semi-quantitative reporter of gene expression, whose useful features are in vivo detection via the G418-resistance phenotype and powerful cell-free assay.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Episomal plasmid ; Copy number control ; Plasmid maintenance ; Glycolytic enzyme levels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This study demonstrates how varying the promoter strength of an essential gene on a yeast 2μORI-STB YEp multicopy vector can influence vector copy levels. A phosphoglycerate kinase gene (PGK) on this plasmid was made essential for fermentative growth by transformation into a pgk - yeast strain. When in these PGK- transformants the requirement for PGK expression was the sole selective criterion for plasmid maintenance, PGK promoter activity was inversely related to vector copy levels. Plasmids with an efficiently-transcribed PGK gene were maintained at approximately one copy per cell, whereas those lacking the UAS that normally directs high basal PGK transcription levels were present at up to 10–15 copies. All cultures of these PGK+ transformants contained only a low proportion of pgk - cells. Since mitotic loss of the plasmid arrests growth through loss of a functional PGK allele, PGK confers high stability to the YEp vector in such a pgk - genetic background. In this system YEp vector levels are probably influenced by PGK transcription because high expression of PGK is needed in rapid fermentative growth. Remarkably, low plasmid PGK promoter activity caused PGK mRNA levels slightly higher than those found in yeast with normal PGK regulation. A higher plasmid copy number is therefore not the only factor counteracting the effects of low PGK transcription, and it is possible that PGK mRNA becomes more stable in response to inefficient PGK transcription.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Sporulation ; Inessential genes ; Genome organization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The SPR6 gene of Saccharomyces cerevisiae encodes a moderately abundant RNA that is present at high levels only during sporulation. The gene contains a long open reading frame that could encode a hydrophilic protein approximately 21 kDa in size. This protein is probably produced by the yeast, because the lacZ gene of Escherichia coli is expressed during sporulation when fused to SPR6 in the expected reading frame. SPR6 is inessential for sporulation; mutants that lack SPR6 activity sporulate normally and produce viable ascospores. Nonetheless, the SPR6 gene encodes a function that is relevant to sporulating cells; the wild-type allele can enhance sporulation in strains that are defective for several SPR functions. SPR6 is located on chromosome V, 14.4 centimorgans centromere-distal to MET6.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Nucleo-mitochondrial interactions ; Mitochondrial status ; Lycorine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In a previous paper we have shown that the alkaloid lycorine inhibits growth of rho +, mit - and rho -, strains of Saccharomyces cerevisiae, whereas strains devoid of mitochondrial DNA (rho o) are resistant to more than 200 μg/ml of the alkaloid. In this report we show that hypersuppressive petites are almost as resistant as rho o mutants, whereas isogenic rho - petites, which have retained tained longer segments of the genome, are sensitive to the drug.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1432-0983
    Keywords: Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; CaMV 35S promoter ; CaMV 35S terminator ; Heterologous expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Complementation of fission yeast mutants by plant genomic libraries could be a promising method for the isolation of novel plant genes. One important prerequisite is the functioning of plant promoters and terminators in Schizosaccharomyces pombe and Saccharomyces cerevisiae. Therefore, we studied the expression of the bacterial β-glucuronidase (GUS) reporter gene under the control of the Cauliflower Mosaic Virus (CaMV) 35S promoter and 35S terminator. We show here that S. pombe initiates transcription at exactly the same start site as was reported for tobacco. The 35S CaMV terminator is appropriately recognized leading to a polyadenylated mRNA of the same size as obtained in plant cells transformed with the same construct. Furthermore, the GUS-mRNA is translated into fully functional GUS protein, as determined by an enzymatic assay. Interestingly, expression of the 35S promoter in the budding yeast S. cerevisiae was found to be only moderate and about hundredfold lower than in S. pombe. To investigate whether different transcript stabilities are responsible for this enormous expression difference in the two yeasts, the 35S promoter was substituted by the ADH (alcohol dehydrogenase) promoter from fission yeast. In contrast to the differential expression pattern of the 35S promoter, the ADH promoter resulted in equally high expression rates in both fission and budding yeast, comparable to the 35S promoter in S. pombe. Since the copy number of the 35S-GUS constructs differs only by a factor of two in the two yeasts, it appears that differential recognition of the 35S promoter is responsible for the different transcription rates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Mitochondria ; Intron-encoded proteins ; Recombination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The respiratory competency of a yeast strain devoid of mitchondrial introns is quite normal. However, it may be asked whether intron-encoded proteins participate in metabolisms other than those of mitochondrial introns. Using strains without mitochondrial introns we have answered two questions. The first was: does the absence of intron-encoded proteins abolsh mitochondrial recombination? The second was: do mitochondrial introns and intron-encoded proteins play a part in mitochondrial DNA rearrangements induced by ethidium bromide (rho- production)? We have shown that the introns and intron-encoded proteins are not essential essential components of either phenomenon.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 18 (1990), S. 23-27 
    ISSN: 1432-0983
    Keywords: Protein translocation ; Saccharomyces cerevisiae ; Peroxisomes ; Overexpression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Import of proteins into organelles usually requires a cis-acting targeting signal. Analysis of various hybrid proteins, consisting of mouse DHFR and parts of catalase A from Saccharomyces cerevisiae, revealed that fusion proteins containing the N-terminal 126 amino acids, or less, of catalase A remain in the cytosol whereas fusion proteins containing 140, or more, N-terminal amino acids of catalase A form large aggregates inside the cell. These protein bodies, which lack a surrounding membrane, copurified with peroxisomes on cell fractionation. The peroxisomal targeting signal of catalase A does not reside at the C-terminus or at the N-terminus.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Microchimica acta 101 (1990), S. 273-279 
    ISSN: 1436-5073
    Keywords: aluminium analysis ; phosphorus ; sulfur ; chlorine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Multi-step procedures for the determination of phosphorus, sulfur and chlorine are described and tested against established methods and on reference materials. Phosphorus is separated as hydrogen phosphide, extracted as phosphomolybdic acid, reduced to molydenum blue and measured photometrically (detection limit 0.05 μg/g). Sulfur is separated after reduction as hydrogen sulfide or by means of pyrohydrolysis and measured by ICP-OES (detection limit 0.1 μg/g). Chloride can be measured by ion chromatography after pyrohydrolytic separation (detection limit 0.1 μg/g). The determination of sulfur was also successfully tested on copper and steel samples.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1573-0832
    Keywords: Nystatin ; amphotericin B ; amphotericin B methyl ester ; polyene antibiotics ; yeast ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Saccharomyces cerevisiae was cultured under anaerobiosis in semi-complete medium to which either palmitoleic or oleic acid was added. Cells were grown at 20 °C or 30 °C. The levels of total lipids, total sterols, and phospholipids were higher in cells grown at 20 °C than at 30 °C. The effects of nystatin (NYS), amphotericin B (AMB), and amphotericin B methyl ester (AME) were evaluated by determining cell viability and liberation of intracellular compounds. The loss of cell viability is higher in the first 30 minutes of incubation with the drugs and is the same regardless of the type of cells obtained. Low molecular weight compounds and ions such as K+ are liberated a few minutes after incubation with the drugs whereas proteins and substances absorbing at 260 nm are liberated later. Phosphate liberation comes after K+ and before compounds of higher molecular weights.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 253-269 
    ISSN: 1573-0867
    Keywords: Nitrogen ; phosphorus ; sulphur ; nutrient balances ; surface waters ; North Sea ; Baltic Sea ; eutrophication ; hypertrophication ; primary production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Dissolved inorganic nitrogen and phosphorus, their relationship to each other (DIN/DIP) as predisposing (nutrient) factors, as well as prevailing weather as a triggering factor all work together to induce the primary production and hence the eutrophication (hypertrophication) process in surface waters. Sulfate likewise is a decisive predisposing factor influencing the eutrophication process by reducing N availability but increasing P availability and thus acting towards an N limitation of the primary production. This is one of the reasons why marine (coastal) waters and estuaries often exhibit N limitation with respect to primary production, while freshwater ecosystems often tend to exhibit P limitation. Within the N and P balance of agriculture of some countries of Western Europe (Netherlands, Denmark, Switzerland, FRG, UK and Sweden for N, resp. Netherlands, FRG and GDR for P) more the level than the efficiency of the N and P applications indicates the extent of the nutrient surplus. Despite 59–73% N utilization in plant production, the rate of 13–23% for agriculture as a whole equals to the 12–21% efficiency of N use in animal production. The varying N surplus in agriculture in the separate countries of 124 to 465 kg N ha−1 a−1 is determined almost exclusively by the level of the N application and not by its efficiency. The situation is similar for P: In spite of P utilization in plant production of 59–76%, P utilization in total agriculture is only 11–38%, or comparable to the P efficiency within animal production of 10–34%. The differing P excess balance of 55 to 88 kg P2O5 ha−1 a−1 is influenced by the level of the P application. The N and P efficacy of total agriculture hence is determined almost completely by that of animal production, since 83–95% (N basis) and 76–94% (P basis) of the total plant production (on top of the nationally varying levels of N and P use via imported feeds) are fed to animals — with the low N and P utilization cited above. Agriculture's share of the N and P emissions into surface water of several countries/regions in Western Europe (FRG, Netherlands, Italy, Denmark, Switzerland, Norway) ranges from 37 to 82% resp. 27 to 38%. Its share in the flus into the North Sea catchment basin will be about 60% for N and 25% for P related only to the anthropogenic material carried by the rivers. Agriculture's share in the atmospheric N emissions into the North and Baltic Seas can be estimated at about 65% or 55%, resp. while the remaining approx. 35% or 45%, resp. are traceable primarily to anthropogenic burning processes. For agriculture the priority lies in limiting N emissions into surface water caused by leaching, erosion and NH3 emissions, and reducing P emissions mainly through soil conservation (protection against erosion) and water protection. As regards N this means a demand for comprehensive protection of groundwater and atmosphere differentiated according to the potential for losses or the risk of losses on a site, also outside the protection zones. As regards P only those areas can be included in the demand for reduction of emissions that are actually threatened by erosion or surface runoff. Plenty of short-term and long-term measures are available to agriculture to reduce N and P emissions. Especially the long-range measures (such as creating nutrient balances on farms and fields, the integration of animal and plant production, maintaining maximum livestock densities according to the ability of areas to absorb nutrients, altered feeding programs in animal nutrition, changes in livestock keeping (slurry→deep litter), increasing the internal and external recycling of N and P) are capable of bringing about a satisfactory degree of success within the next 20 to 30 years.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 23 (1990), S. 73-80 
    ISSN: 1573-0867
    Keywords: Nigerian savanna ; maize ; potassium ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A three year field study was conducted at five locations in the Nigerian savanna to evaluate the response of early maturing maize variety to varying rates of K and Zn with a view to establishing the K and Zn requirements for maize production in this zone. Treatments consisted of 4 × 3 factorial combinations of 4 levels of K and 3 levels of Zn. Responses to K and Zn fertilization were sporadic and were obtained only in soils of the Southern Guinea savanna and in the soil formed on sedimentary sandstone. There seem to be no problem at present in soils of the Northern Guinea and Sudan savannas where leaching is less intense. It is inferred from this study that K and Zn deficiences are incipient in the high rainfall soils and in the sandstone derived soils. For these soils, 50 kg K/ha and 2–5 kg Zn/ha is suggested as adequate for an early maturing maize crop. Soil data showed that K and Zn responses can be expected when available K and Zn levels fall below 0.1 meq/100 g and 2 ppm respectively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 229-235 
    ISSN: 1573-0867
    Keywords: Grass ; wheat ; nitrogen nutrition ; dilution curve ; mineral content ; mineral removal ; phosphorus ; potassium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The important effect of nitrogen in changing the patterns of mineral content and mineral removal is analysed for grass swards and wheat. Different models are proposed; accumulated dry matter developed throughout a growing period is shown to be an excellent reference for assessing the evolution of the plant mineral content and the mineral removal the growing crop. Applications in diagnosing mineral nutrition status and optimising fertilizer use are proposed and discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 249-252 
    ISSN: 1573-0867
    Keywords: Long-term manure trial ; residual effect ; model test ; nitrogen availability ; maize ; Italian ryegrass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Sluijsmans and Kolenbrander developed a simple model to describe the availability of animal manure, assuming a readily available, an easily decomposable and a slowly decomposable N fraction. We tested this model on data from an experiment in which farmyard manure had been applied for eleven successive years to silage maize [Zea mays L.] grown on a light sandy soil. The residual effects of this FYM were then measured by growing Italian ryegrass [Lolium multiflorum Lamk.] in the 12th year. The measured uptake of N by the grass of the FYM residues was then compared with the computed values. The measured amounts of N taken up agreed fairly well with the calculated amounts for applications of 50 and 100 t FYM per ha per year. If the rates of manure application are adjusted to crop requirement, the model shows that the potential, long-term release of N from the residual N fraction of FYM will not exceed 20 kg N per ha. For cattle slurry with a smaller residual fraction, the release will be at most 10% of the total annual N application.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    ISSN: 1572-9699
    Keywords: 2-Deoxy-D-glucose transport ; polyphosphate ; Saccharomyces cerevisiae ; sugar phosphorylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The role of polyphosphate in 2-deoxy-D-glucose transport was studied in yeast cells, pulse-labeled with [32P]orthophosphate, by comparing the concentrations and specific activities of polyphosphate, orthophosphate and 2-dGlc-phosphate. When 2-dGlc transport was measured under aerobic conditions, it appeared that polyphosphate replenished the orthophosphate pool, indicating that polyphosphate has, at least mainly, an indirect role in sugar phosphorylation. Also in cells with a reduced respiratory capacity, due to a treatment with antimycin A, no direct role for polyphosphate in 2-dGlc transport could be detected. Under these conditions, only a very limited breakdown of polyphosphate occurred, probably because of the small decrease in the orthophosphate concentration.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 46 (1990), S. 193-200 
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; protein toxin ; yeast toxin precursor ; protease processing ; lectin ; (1→6)-β-D-glucan ; receptor ; resistant mutants ; spheroplasts ; ion-permeable channels ; site-directed mutagenesis ; toxin functional domains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The K1 killer toxin ofSaccharomyces cerevisiae is a secreted, virally-coded protein lethal to sensitive yeasts. Killer yeasts are immune to the toxin they produce. This killer system has been extensively examined from genetic and molecular perspectives. Here we review the biology of killer yeasts, and examine the synthesis and action of the protein toxin and the immunity component. We summarise the structure of the toxin precursor gene and its protein products, outline the proteolytic processing of the toxin subunits from the precursor, and their passage through the yeast secretory pathway. We then discuss the mode of action of the toxin, its lectin-like interaction with a cell wall glucan, and its probable role in forming channels in the yeast plasma membrane. In addition we describe models of how a toxin precursor species functions as the immunity component, probably by interfering with channel formation. We conclude with a review of the functional domains of the toxin structural gene as determined by site-directed mutagenesis. This work has identified regions associated with glucan binding, toxin activity, and immunity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 154 (1990), S. 267-273 
    ISSN: 1432-072X
    Keywords: Yeast ; Saccharomyces cerevisiae ; (R)-2,3-Butanediol dehydrogenase ; Stereospecificity ; Gas chromatographic analysis of enantiomers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A NAD-dependent (R)-2,3-butanediol dehydrogenase (EC 1.1.1.4), selectively catalyzing the oxidation at the (R)-center of 2,3-butanediol irrespective of the absolute configuration of the other carbinol center, was isolated from cell extracts of the yeast Saccharomyces cerevisiae. Purification was achieved by means of streptomycin sulfate treatment, Sephadex G-25 filtration, DEAE-Sepharose CL-6B chromatography, affinity chromatography on Matrex Gel Blue A and Superose 6 prep grade chromatography leading to a 70-fold enrichment of the specific activity with 44% yield. Analysis of chiral products was carried out by gas chromatographic methods via pre-chromatographic derivatization and resolution of corresponding diasteromeric derivatives. The enzyme was capable to reduce irreversibly diacetyl (2,3-butanediol) to (R)-acetoin (3-hydroxy-2-butanone) and in a subsequent reaction reversibly to (R,R)-2,3-butanediol using NADH as coenzyme. 1-Hydroxy-2-ketones and C5-acyloins were also accepted as substrates, whereas the enzyme was inactive towards the reduction of acetone and dihydroxyacetone. The relative molecular mass (M r) of the enzyme was estimated as 140 000 by means of gel filtration. On SDS-polyacrylamide gel the protein decomposed into 4 (identical) subunits of M r 35 000. Optimum pH was 6.7 for the reduction of acetoin to 2,3-butanediol and 7.2 for the reverse reaction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1432-072X
    Keywords: cAMP ; Cat mutants ; Glucose repression ; Glucose-induced ; Intracellular pH ; Ras ; Saccharomyces cerevisiae ; Signal transduction ; Trehalase ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Addition of glucose to derepressed cells of the yeast Saccharomyces cerevisiae induces a transient, specific cAMP signal. Intracellular acidification in these cells, as caused by addition of protonophores like 2,4-dinitrophenol (DNP) causes a large, lasting increase in the cAMP level. The effect of glucose and DNP was investigated in glucose-repressed wild type cells and in cells of two mutants which are deficient in derepression of glucose-repressible proteins, cat1 and cat3. Addition of glucose to cells of the cat3 mutant caused a transient increase in the cAMP level whereas cells of the cat1 mutant and in most cases also repressed wild type cells did not respond to glucose addition with a cAMP increase. The glucose-induced cAMP increase in cat3 cells and the cAMP increase occasionally present in repressed wild type cells however could be prevented completely by addition of a very low level of glucose in advance. In derepressed wild type cells this does not prevent the specific glucose-induced cAMP signal at all. These results indicate that repressed cells do not show a true glucose-induced cAMP signal. When DNP was added to glucose-repressed wild type cells or to cells of the cat1 and cat3 mutants no cAMP increase was observed. Addition of a very low level of glucose before the DNP restored the cAMP increase which points to lack of ATP as the cause for the absence of the DNP effect. These data show that intracellular acidification is able to enhance the cAMP level in repressed cells. The glucose-induced artefactual increase occasionally observed in repressed cells is probably caused by the fact that their low intracellular pH is only restored after the ATP level has increased to such an extent that it is no longer limiting for cAMP synthesis. It is unclear why the artefactual increases are not always observed. Measurement of glucose- and DNP-induced activation of trehalase confirmed the physiological validity of the changes observed in the cAMP level. Our results are consistent with the idea that the glucose-induced signaling pathway contains a glucose-repressible protein and that the protein is located before the point where intracellular acidification triggers activation of the pathway.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1432-072X
    Keywords: Saccharomyces cerevisiae ; Catalase A ; Catalase T ; β-Oxidation ; Microbodies ; H2O2-Metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The parental strain (A+T+) of Saccharomyces cerevisiae and mutants, deficient in catalase T (A+T−), catalase A (A−T+) or both catalases (A−T−), grew on ethanol and oleic acid with comparable doubling times. Specific activities of catalase were low in glucose- and ethanol-grown cells. In the two oleic acid-grown A+-strains (A+T+ and A+T−) high catalase activities were found; catalase activity invariably remained low in the A−T+ strain and was never detected in the A−T− strain. The levels of β-oxidation enzymes in oleic acid-grown cells of the parental and all mutant strains were not significantly different. However, cytochrome C peroxidase activity had increased 8-fold in oleic acid grown A− strains (A−T+ and A−T−) compared to parental strain cells. The degree of peroxisomal proliferation was comparable among the different strains. Catalase A was shown to be located in peroxisomes. Catalase T is most probably cytosolic in nature and/or present in the periplasmic space.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 153 (1990), S. 384-391 
    ISSN: 1432-072X
    Keywords: Saccharomyces cerevisiae ; Ethanol ; Acetic acid ; Cytoplasmic pH ; 31P-NMR ; 13C-NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cell suspensions of a respiratory deficient mutant of Saccharomyces cerevisiae were monitored by in vivo 31P and 13C Nuclear Magnetic Resonance in order to evaluate the effect of ethanol in intracellular pH and metabolism. In the absence of an added energy source, ethanol caused acidification of the cytoplasm, as indicated by the shift to higher field of the resonance assigned to the cytoplasmic orthophosphate. Under the experimental conditions used this acidification was not a consequence of an increase in the passive influx of H+. With cells energized with glucose, a lower value for the cytoplasmic pH was also observed, when ethanol was added. Furthermore, lower levels of phosphomonoesters were detected in the presence of ethanol, indicating that an early event in glycolysis is an important target of the ethanol action. Acetic acid was identified as responsible for the acidification of the cytoplasm, in experiments where [13C]ethanol was added and formation of labeled acetic acid was detected. The intracellular and the extracellular concentrations of acetic acid were respectively, 30 mM and 2 mM when 0.5% (120 mM) [13C]ethanol was added.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    ISSN: 1432-072X
    Keywords: Regulatory mutants ; Meiotic mapping ; Transcriptional regulation ; MAL genes ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The MAL1 locus of Saccharomyces cerevisiae comprises three genes necessary for maltose utilization: a regulatory (MALR), a maltose transport (MALT) and a maltase gene (MALS). A fine structure genetic map of the MAL1R gene was constructed and the order of mutations was confirmed by plasmid-mediated chromosomal recombination. The mutations cluster non-randomly within the 5′ half of the gene, where the putative DNA binding domain of the encoded protein is located. Only mutations mal1 R-22 and MAL1R-72 map in the 3′ terminal half of the gene; these mutations cause a different pattern of transcriptional regulation of plasmid-borne MAL6T genes. Experiments supporting a direct involvement of the MALR-encoded protein in carbon catabolite repression of MAL gene expression are reported.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 1573-4927
    Keywords: mutator ; transposable element ; alcohol dehydrogenase ; maize ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A secondary mutant, derived from an allele of maize alcohol dehydrogenase 1 (Adh1) carrying a Mutator transposable element (Mu1) in its first intron, was reported to exhibit a threefold decrease in ADH enzymatic activity and steady-state RNA levels compared to the original mutant. The original mutant,Adh1-S3034 (abbreviatedS3034), was previously characterized at the molecular level. The derivative, abbreviatedS3034b, has now been cloned; at the DNA sequence level the insertion and surroundingAdh1 sequences are indistinguishable fromS3034. Furthermore, in our lines there is no difference in relative ADH activities between products of the two putative alleles. A comparison of gene expression in heterozygotes obtained by crossing to different tester lines reveals a correlation between the measured decrease in levels of ADH polypeptide produced by the mutant allele and the background in which it is measured; this effect is distinct from any background-related variation in the expression of the progenitor allele. It does not appear to be attributable to alternative patterns of DNA modification. It appears to reflect a background-associated difference in the level of normalAdh1-RNA produced. Thus the previously reported distinction betweenS3034 andS3034b may be due to differences in the extent to which the mutant allele and a given genetic background interact to produce functionalAdh1-RNA.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1573-4919
    Keywords: bovine heart fatty acid-binding protein ; H-FABPc ; heterologous gene expression ; Saccharomyces cerevisiae ; GALIO promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The unicellular eukaryotic microorganism, Saccharomyces cerevisiae, transformed with a plasmid containing a cDNA fragment encoding bovine heart fatty acid-binding protein (H-FABP) under the control of the inducible yeast GAL10 promoter, expressed FABP during growth on galactose. The maximum level of immunoreactive FABP, identical in size to native protein as judged from SDS-polyacrylamide gel electrophoresis, was reached after approximately 16 hours of induction. Analysis of particulate and soluble subcellular fractions showed that FABP was exclusively associated with the cytosol. FABP expressed in yeast cells was functional as was demonstrated by its capacity to bind 14C-oleic acid in an in vitro assay. Growth of the transformants on galactose as the carbon source was significantly retarded at 37°C. Whereas the fatty acid pattern of total lipids was not altered in transformed cells, desaturation of exogenously added 14C-palmitic acid was significantly reduced both at 30 and 37°C. The lowest percentage of radioactively labeled unsaturated fatty acids was found in the phospholipid fraction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 28 (1990), S. 337-346 
    ISSN: 1573-4927
    Keywords: glutamate dehydrogenase ; Drosophila melanogaster ; gene expression ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have isolated theDrosophila melanogaster locus coding forl-glutamate dehydrogenase (EC 1.4.1.3) by virtue of its similarity to the corresponding human gene. There is only one copy of this gene in the fruit fly genome, located on the right arm of chromosome 3 (95D1-4). The transcript includes at least one large intron and matures to a ∼2.4-kb-long polyadenylated RNA whose expression is under developmental control.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 1573-1561
    Keywords: Leafhopper ; Dalbulus maidis ; Homoptera ; Cicadellidae ; hostfinding ; maize ; visual ; olfactory ; synergism ; pest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Virtually nothing is known about the role plant volatiles play in host-finding by Homoptera in the Suborder Auchenorrhyncha. In laboratory bioassays, we examined the influence of plant volatiles on orientation and postcontact behaviors of the leafhopper,Dalbulus maidis, and determined the relationship between visual and olfactory stimuli during host-finding. When compared to the number of contacts made with reflected green light in the presence of a hexane control,D. maidis made more contacts when exposed to volatile extracts from its preferred host, maize; a similar number of contacts when exposed to volatiles from a marginal host, gamagrass; and fewer contacts when exposed to volatiles from a nonhost, sorghum. There was no difference between males and females in the number of contacts made with green light when exposed to maize volatiles compared to hexane alone. More contacts were made with green light than with white light of similar intensity, both in the presence and in the absence of olfactory stimuli; however, maize volatiles acted as a Synergist by increasing the number of contacts leafhoppers made with green light. After contacting the green light, exposure of maize volatiles significantly increased, relative to hexane, the amount of stationary time, but did not influence the amount of time spent moving, the distance traveled, or the speed while moving when within the boundaries of the green light. This study provides the first evidence for an interaction between visual and olfactory stimuli during host-finding for a leafhopper and also for olfactory mediation of postcontact behaviors not associated with feeding.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 16 (1990), S. 2429-2439 
    ISSN: 1573-1561
    Keywords: Cucumis sativus ; ferulic acid ; split root ; phosphorus ; potassium ; water ; net uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Since distribution of allelopathic compounds in soils is highly variable, injurious effects by such compounds should be related to the frequency of contact with roots. Experiments were conducted to determine how P, K, and water uptake of cucumber seedlings were affected as the fraction of roots in contact with ferulic acid (FA) was increased. Seedlings were grown in Hoagland's nutrient solution for 14 days and then transferred to 0.5 mM CaSO4 solution for 24 hr before being placed into a split-root culture system. The containers in the system were filled with 0.5 mM concentrations of KH2PO4 and CaSO4 or 0.5 mM concentrations of KH2PO4, CaSO4, and ferulic acid (FA). Net uptake of P by seedlings (milligrams per seedling) decreased in a curvilinear (concave) manner as the fraction of the roots in contact with FA increased. Net uptake of K (milligrams per seedling) and water (milliliters per seedling) by seedlings decreased linearly as the fraction of the roots in contact with FA increased. Net uptake of P, K, and water by seedlings was reduced 57, 75, and 29%, respectively, when the whole root system was exposed to FA. Net P and K uptake of roots (milligrams per gram root fresh weight) not in contact with FA decreased in a linear and curvilinear (convex) manner, respectively, as the fraction of roots in contact with FA increased. Net P and K uptake of roots in contact with ferulic acid increased in a linear and curvilinear (convex) manner, respectively. Net water uptake of roots (milliliters per gram root fresh weight) not in contact with FA increased in a curvilinear (concave) manner as the frequency of the roots in contact with FA increased. Net water uptake of roots in contact with FA did not show a trend. Transpiration (milliliters per square centimeter) was reduced in a linear manner as the fraction of roots in contact with FA increased. A very slight compensation by roots not in contact with FA for roots in contact with FA was observed for net water uptake rates. No compensation for P and K uptake rates was observed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 28 (1990), S. 337-346 
    ISSN: 1573-4927
    Keywords: glutamate dehydrogenase ; Drosophila melanogaster ; gene expression ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have isolated theDrosophila melanogaster locus coding forl-glutamate dehydrogenase (EC 1.4.1.3) by virtue of its similarity to the corresponding human gene. There is only one copy of this gene in the fruit fly genome, located on the right arm of chromosome 3 (95D1-4). The transcript includes at least one large intron and matures to a ∼2.4-kb-long polyadenylated RNA whose expression is under developmental control.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 28 (1990), S. 445-457 
    ISSN: 1573-4927
    Keywords: mouse ; hemoglobin ; embryonic ; adult ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Adult alpha-globin in mice is synthesized in large amounts during development, first in the primitive, nucleated erythrocytes of yolk sac origin and later in the definitive, nonnucleated erythrocytes that differentiate in the fetal liver, spleen, and bone marrow. Isoelectric focusing analysis of hemoglobins of mice with theHba g2 andHba c haplotypes shows that the ratios of alpha chain 1 to chain 5m and alpha chain 1 to chain 4 in adult hemoglobins fromHba g2 andHba c mice, respectively, change between day 11.5 and day 16.5 of gestation in nucleated red cells, while no change occurs in nonnucleated red cells. The percentage ratios of the two different alpha-globin chains are different inHba g2 andHba c mice for EII, EIII, and adult hemoglobin. In nucleated red cells of yolk sac origin, differences and changes in alpha-globin ratios are a composite of changing globin gene transcription and posttranslational competitive affinities among globins to form embryonic and adult hemoglobin tetramers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 14 (1990), S. 207-216 
    ISSN: 1573-5028
    Keywords: developmental mutant ; gene expression ; nodule formation ; Pisum sativum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mutational analysis of Pisum sativum L. was used to search for constitutive proteins that might function in nodule formation. The sym 5 locus is a mutational hot spot, represented by seven independently derived mutant lines with decreased nodulation. Comparison of two-dimensional polyacrylamide gels of in vitro-translated root RNA showed a consistent difference in the migrational pattern of one peptide. In the nodulating parental cultivar ‘Sparkle’, a 66 kDa peptide had a pI of 5.9. In four of the five tested sym 5 mutants, the 66 kDa peptide had a more acidic pI of 5.8. This 66 kDa peptide is found in lateral root, tap root, and shoot. Its expression was independent of rhizobial inoculation, root temperature, or light.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 1573-5028
    Keywords: auxin action ; cDNA clone ; gene expression ; developmental regulation ; strawberry fruit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A complementary DNA (cDNA) library has been constructed in λgt10 from poly(A)+ mRNA isolated from auxin-deprived strawberry receptacles. By differential plaque filter hybridization, a cDNA (λSAR5) to an auxin-repressed mRNA has been isolated. The expression of the auxin-repressed gene is studied at various stages of normal fruit development and in fruits of variant strawberry genotype using λSAR5 as a probe. Northern analyses of RNA isolated from pollinated and unpollinated fruits of various developmental stages revealed that mRNA corresponding to the λSAR5 clone is repressed during normal fruit development, and the level of λSAR5 mRNA is regulated by endogenous auxin. Furthermore, results with both normal and variant genotype strawberry fruit indicate that there is a positive correlation between growth of strawberry fruit and repression of mRNA corresponding to the λSAR5 clone. The λSAR5 cDNA has been sequenced and is 723 nucleotides in length. The deduced protein has 111 amino acid residues with a molecular mass of 12.5 kDa. The putative polypeptide starts at nucleotide position 20 and ends at 352. The molecular weight of the predicted polypeptide is in agreement with the molecular weight of the in vitro translated polypeptide of hybrid selected mRNA. A comparison of the nucleotide and deduced amino acid sequence of λSAR5 with nucleotide and protein sequences in data banks has not revealed any homology to known proteins.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 14 (1990), S. 333-347 
    ISSN: 1573-5028
    Keywords: intergenic spacer ; maize ; methylation ; rDNA ; teosinte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The restriction endonucleases Hpa II and Msp I were used to examine cytosine methylation in the ribosomal RNA genes (rDNA) of inbred lines of maize and species of teosinte. In all of the rDNAs examined, Msp I (not sensitive to mCpG) digestion yielded a distribution of lower molecular weight fragments indicative of multiple recognition sites. The majority of the rDNA arrays in an individual were inaccessible to Hpa II (sensitive to mCpG) cleavage, but a significant fraction (10–25%) was cleaved at least once by Hpa II into repeat unit length fragments (9.1 kbp). In some maize inbred lines, one or two additional fragment populations (less than 9.1 kbp in length) were also produced by Hpa II digestion. All of the unmethylated Hpa II sites mapped to the intergenic spacer (IGS), and the major unmethylated site was located approximately 800 bp 5′ to the start of the 18S RNA coding sequence. An Eco RI polymorphism, present in the 26S gene of certain inbred lines and hybrids, was utilized to investigate the organization of unmethylated repeat units in the rDNA array. In double digest experiments with Hpa II/Eco RI, the fragments from repeat units with two Eco RI sites were sensitive to Hpa II digestion, whereas, the fragments from repeat units with a single Eco RI site were almost completely resistant to Hpa II digestion. Similar digestion patterns were also observed in Eco RII (sensitive to mCNG)/Eco RI digests. These results suggest that unmethylated and Eco RI polymorphic sites occur in the same repeat units.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    ISSN: 1573-5028
    Keywords: auxin action ; cDNA clones ; developmental regulation ; gene expression ; strawberry fruit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By differential hybridization, two auxin-inducible cDNA clones (λSAR1 and λSAR2) have been isolated from a cDNA library constructed to poly(A)+ mRNA from auxin-treated strawberry receptacles. Both the clones have been used as probes to study the expression of the auxin-induced genes in pollinated and unpollinated fruits of various stages of development and in different organs. A high level of auxin-induced mRNAs is found in pollinated fruits as compared to unpollinated fruits of the same age, suggesting that the expression of the auxin-induced genes is developmentally regulated and the level of auxin-induced mRNAs is regulated by endogenous auxin. Furthermore, our data on the expression of λSAR1 and λSAR2 genes in pollinated and unpollinated fruits revealed a positive correlation between growth of strawberry fruit and the induction of mRNA corresponding to the λSAR1 and λSAR2 clones. Ethylene has no effect on the expression of the auxin-induced mRNAs. λSAR1 mRNA is not detected in other parts of strawberry plants whereas λSAR2 mRNA is present in roots. Furthermore, mRNA corresponding to λSAR1 and λSAR2 is not detected in other auxin-responsive plant systems such as pea epicotyls and bean explants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    ISSN: 1573-5028
    Keywords: Lupinus polyphyllus ; cell culture ; cDNA clone ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 15 (1990), S. 783-785 
    ISSN: 1573-5028
    Keywords: sorghum ; maize ; glycine-rich proteins ; RNA-binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Springer
    Molecular biology reports 14 (1990), S. 1-9 
    ISSN: 1573-4978
    Keywords: prosomes ; messenger RNP ; intermediate filaments ; heat shock complex ; multicatalytical protease (MCP) ; protein synthesis ; gene expression ; differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract PROSOMES are a novel class of small RNP particles of uniform morphology, but of variable RNA (pRNA) and protein composition (about 650 000 MW; 12 nm diameter in the EM). They were discovered as subcomplexes of free mRNP, tightly attached to inactive mRNA in the cytoplasm. The pRNAs hybridize stably to mRNA. Prosomes associate in vitro to mRNA and inhibit cell free protein synthesis inducing an mRNA structure unable to interact with ribosomes. Many types of prosomes were observed. The individual particle is made up by a variable combination of about 20 characteristic proteins and one or several pRNA. Some prosomal proteins are glycosylated, phosphorylated and, possibly, ADP-ribosylated and are highly conserved in evolution whilst others vary with the species and the mRNA population they are associated to. A protease activity was found associated to prosomes. The function(s) of the prosomes is(are) still unknown. The differential inhibition of in vitro protein synthesis points to a capacity to recognize mRNA and to keep it in an inactive state. The observation with the aid of monoclonal antibodies (pMABs) that prosomes and thus mRNP are attached to the intermediate filaments (IF) raises the question if one of the functions of the IF might be in the topological distribution of mRNA within the cell. Similar to the cytokeratin fibers, the prosome networks bridge neighboring cells at specific positions. — The nucleus also contains some prosomal antigens, located on chromosomes and on the nuclear matrix. Their presence and distribution in the cell compartments varies with the cell type and the prosomal antigen probed. Oocytes contain large amounts of prosomes. In embryonic development, the synthesis of individual prosomal proteins starts progressively after the blastula stage and resumes fully in gastrulation only; cleavage and blastula stage prosomes are thus of maternal origin. The nucleo-cytoplasmic distribution of prosomal antigens changes in embryos, with the stage of development and type of differentiation. In human tissues specific patterns of prosomal antigens were found in function of cell type and differentiation. In view of these data, the hypothesis may be formulated that prosomes are a population of mRNA-linked RNP which includes particles of varying individual composition and hence specificity. Attached to IF sub-networks, specific types of prosomes might accompany families of mRNA in function of the physiological state and the specialisation of given differentiated cell types. The cell-type specific organisation of the IF networks might be related to the messenger RNA complement of a given cell, and to its status of gene expression. The prosomes might thus have a function in controlling the transport, distribution and control of activity of specific mRNAs in the cell.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 14 (1990), S. 1-15 
    ISSN: 1573-5028
    Keywords: cDNA ; differential screening ; genomic cloning ; maize ; tandem genes ; α-tubulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The identification of a cDNA (MR19) corresponding to a maize α-tubulin and homologous genomic clones (MG19/6 and MG19/14) is described. The cDNA has been isolated by differential screening of a cDNA maize root library. We have found two α-tubulin genes in a tandem arrangement in the genomic clones, separated by approximately 1.5 kbp. One of the genes (gene I) contains an identical nucleotide sequence which corresponds to the cDNA clone. The two deduced proteins from DNA sequences are very similar (only two conservative replacements in 451 amino acids) and they share a high homology as compared with the published α-tubulin sequences from other systems and in particular with the Arabidopsis thaliana and Chlamydomonas reinhardtii sequences reported. The structure of both genes is also very similar; it includes two introns, of 1.7 kbp and 0.8 kbp respectively, in each gene and only one intron placed at a homologous position in relation to Arabidopsis thaliana genes. By using specific 3′ probes it appears that both genes are preferentially expressed in the radicular system of the plant. The α-tubulin gene family of Zea mays seems to be represented by at least 3 or 4 members.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 14 (1990), S. 585-594 
    ISSN: 1573-5028
    Keywords: cytokinin ; gene expression ; mRNA ; nitrate reductase ; transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To investigate the molecular mechanism of cytokinin regulation of nitrate reductase (NR) activity, the influence of benzyladenine (BA) on the level of NR transcript was studied in etiolated barley leaves using a barley NR cDNA as a probe. Northern blot analyses of the levels of NR poly (A)+ RNA indicate that the amount present is proportional to the concentration of BA (2×10-8 to 2×10-4 M) applied to the leaves. Enhancement of NR mRNA by 2×10-5 M BA was clearly detected after 15 minutes of exposure of the leaves to light. The enhancement is cytokinin-specific and adenine is ineffective. Brief treatment with the protein synthesis inhibitor, cycloheximide, inhibited BA-enhanced NR activity but did not inhibit BA-enhanced NR transcript level, thus the enhancement was independent of concurrent protein synthesis. Nuclear runoff transcription studies showed that the enhancement of NR mRNA was at least partially due to increased transcription rates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    ISSN: 1573-5028
    Keywords: gene expression ; glutamine synthetase ; leghaemoglobin ; nitrogen metabolism ; Phaseolus vulgaris ; root nodules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this paper we have examined whether the four glutamine synthetase (gln) genes, expressed in roots and nodules of Phaseolus vulgaris are substrate-inducible by ammonium. Manipulation of the ammonium pool in roots, through addition and removal of exogenous ammonium, did not elicit any changes in the abundances of the four mRNAs thus suggesting that the gln genes in roots of this legume are neither substrate-inducible by ammonium nor derepressed during nitrogen starvation. In nodules the effect of the ammonium supply on expression of the gln genes has been examined by growing nodules under argon/oxygen atmospheres, or with a number of Fix- Rhizobium mutants, and following addition of exogenous ammonium. The results of these experiments suggest that the expression of the gln-γ gene, which is strongly induced during nodule development, is primarily under a developmental control. However nitrogen fixation appears to have a quantitative effect on expression of gln-γ as the abundance of this mRNA is about 2 to 4-fold higher under nitrogen-fixing conditions. This effect could not be mimicked by addition of exogenous ammonium and moreover is not specific to the gln-γ gene as mRNA from a leghaemoglobin gene was similarly affected. Taken together these results have failed to find an effect of ammonium on specifically inducing the expression of glutamine synthetase genes in roots and nodules of P. vulgaris.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 1573-5028
    Keywords: maize ; Coix ; zein ; coixin ; phylogenetic relationship
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Zeins from Zea mays L cv. Maya and coixins from Coix lacryma-jobi L. cv. Adlay were fractionated to obtain α-, β-, and γ-zein and α-, β-, and γ-coixin. The α-coixins were composed of 4 polypeptide classes of 27 kDa (C1), 25 kDa (C2), 17 kDa (C4) and 15 kDa (C5) with solubility properties very similar to those of the 22 kDa and 19 kDa α-zeins. Like the α-zeins, the C1 and C2 α-coixins corresponded to 80% of total Coix prolamins. The fraction corresponding to γ-coixin contained only one protein band of 22 kDa (C3). This coixin fraction has solubility properties similar to those of γ-zein and represents 15% of the total coixin. The β-zein fraction was composed of a major 17 kDa protein band, while the β-coixin fraction consisted of a mixture of α- and γ-coixins. Polyclonal antibodies raised against C1 recognized C1 and C2 and cross-reacted strongly with the 22 kDa α-zein, as did C4 and C5 antisera. The antiserum against γ-coixin showed strong cross-reaction with γ-zein. The homology between coixins and zeins was further investigated by using Southern hybridization analyses. The genomic DNA of maize and Coix were digested with several restriction enzymes and probed with cDNA clones representing 19 and 22 kDa α-zeins as well as the 28 and 16 kDa γ-zeins. The Coix genome showed complex cross-hybridization sequences with the 22 kDa α-zein cDNA, while no cross-hybridization was observed with the 19 kDa cDNA clone. The cDNA clone representing the 28 kDa γ-zein cross-hybridized with only one band of Coix genomic DNA, in contrast to the three bands observed in maize. This same Coix sequence also cross-hybridized with the cDNA clone representing the 16 kDa γ-zein. The relevance of these findings are discussed in the context of the origin of zein and coixin genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 1573-5028
    Keywords: antisense ; gene expression ; plants ; regulation ; RNA ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have shown leaf-specific inhibition GUS gene expression in transgenic Nicotiana plants using an antisense RNA with a 41-base homology spanning the translation start codon of the gene. GUS was expressed from the nominally constitutive 35S promoter and the antisense RNA was expressed from the light-regulated ca/b promoter of Arabidopsis thaliana. A range of GUS inhibition from 0 to 100% was obtained by screening a small population of transgenic plants and the specific levels of inhibition observed were stably inherited in two generations. An antiGUS ‘gene’ dosage effect was observed in plants which were homozygous for antiGUS. RNA detection results suggest that duplex formation with the 41 base pair antiGUS RNA destabilized the GUS mRNA and that an excess of antisense. RNA was not required. Our results demonstrate the potential of antisense RNA as a strategy for obtaining plant mutants, especially ‘down mutations’ in essential genes where only a short 5′ sequence of the mRNA is required. They also suggest that the ‘position effect’ on gene expression could be used in conjunction with an antisense RNA strategy to provide a versatile approach for crop improvement.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1573-5028
    Keywords: Nicotiana tabacum ; fungal disease resistance ; groundnut stilbene synthase ; gene expression ; resveratrol synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A gene from groundnut (Arachis hypogaea) coding for stilbene synthase was transferred together with a chimaeric kanamycin resistance gene. It was found to be rapidly expressed after induction with UV light and elicitor in tobacco cells (Nicotiana tabacum). Comparative studies of stilbene synthase mRNA synthesis in groudnut and transgenic tobacco suspension cultures revealed the same kinetics of gene expression. Stilbene synthase specific mRNA was detectable 30 minutes after elicitor induction and 10 minutes after UV irradiation. The maximum of mRNA accumulation was between 2 and 8 hours post induction. 24 hours after induction stilbene synthase mRNA accumulation ceased. Furthermore, in transgenic tobacco plants, the gene was found to be inducible in sterile roots, stems and leaves. Stilbene synthase was demonstrated in crude protein extracts from transgenic tobacco cell cultures using specific antibodies. Resveratrol, the product of stilbene synthase, was identified by HPLC and antisera raised against resveratrol.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1573-5028
    Keywords: maize ; ABA-induced gene ; protein phosphorylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ABA-induced MA12 cDNA from maize, which encodes a set of highly phosphorylated embryo proteins, was used to isolate the corresponding genomic clone. This gene, called RAB-17 (responsive to ABA), encodes a basic, glycine-rich protein (mol. wt. 17 164) containing a cluster of 8 serine residues, seven of them contiguous. It is a homologue of the rice RAB-21 gene (Mundy J, Chua NH, EMBO J 7; 2279–2286, 1988). Phosphoamino acid analysis of the isolated protein indicates that only the serine residues are phosphorylated and a putative casein-type kinase phosphorylatable sequence was identified in the protein. The pattern of expression and in vivo phosphorylation of the RAB-17 protein was studied during maize embryo germination and in calli of both meristematic or embryonic origin. ABA treatment induced the synthesis of RAB-17 mRNA and protein in calli, however, the RAB-17 proteins were found to be highly phosphorylated only in embryos.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 14 (1990), S. 1055-1056 
    ISSN: 1573-5028
    Keywords: Lupinus polyphyllus ; cell culture ; cDNA clone ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 1573-5028
    Keywords: salt stress ; abscisic acid ; cDNA sequence ; gene expression ; LEA protein sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have characterized a new tomato cDNA, TAS14, inducible by salt stress and abscisic acid (ABA). Its nucleotide sequence predicts an open reading frame coding for a highly hydrophilic and glycine-rich (23.8%) protein of 130 amino acids. Southern blot analysis of tomato DNA suggests that there is one TAS14 structural gene per haploid genome. TAS14 mRNA accumulates in tomato seedlings upon treatment with NaCl, ABA or mannitol. It is also induced in roots, stems and leaves of hydroponically grown tomato plants treated with NaCl or ABA. TAS14 mRNA is not induced by other stress conditions such as cold and wounding. The sequence of the predicted TAS14 protein shows four structural domains similar to the rice RAB21, cotton LEA D11 and barley and maize dehydrin genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 15 (1990), S. 913-920 
    ISSN: 1573-5028
    Keywords: Adh1 ; chloramphenicol acetyl transferase ; enhancer ; intron ; maize ; transient expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chimeric genes containing the coding sequence for bacterial chloramphenicol acetyl transferase (CAT) have been introduced by electroporation into maize protoplasts (Black Mexican Sweet) and transient expression monitored by enzyme assays. Levels of CAT expression were enhanced 12-fold and 20-fold respectively by the inclusion of maize alcohol dehydrogenase-1 introns 2 and 6 in the chimeric construct. This enhancement was seen when the intron was placed within the 5′ translated region but not when it was located upstream of the promoter or within the 3′ untranslated region. Deletion of exon sequences adjacent to intron 2 abolished its ability to mediate enhancement of CAT gene expression. Northern analysis of protoplasts electroporated with intron constructs revealed elevated levels of CAT mRNA. However, this elevation was insufficient to account for the increased enzyme activity. One explanation of these results is that splicing affects both the quantity of mRNA.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 116 (1990), S. 93-105 
    ISSN: 1432-1424
    Keywords: clathrin ; genetics ; Saccharomyces cerevisiae ; exocytosis ; endocytosis ; prohormone maturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Potato research 33 (1990), S. 13-21 
    ISSN: 1871-4528
    Keywords: hormones ; media ; phosphorus ; rooting depth ; solar radiation ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary To expand potato production in developing countries using cuttings as a source of good quality planting material, requires simple low cost methods to root and establish them. Experiments at a warm tropical site in the Philippines, to determine appropriate methods, showed that simple media ranging from fine sand to clay subsoil mixed with rice hulls enabled rooting which was not improved by hormones. Nitrogen rich media, such as volcanic soil or compost with additional P, were best for developing cuttings into strong transplants but there were no major differences in root and shoot development from cuttings differing in size and age. Tuberizations was favored by increasing the number of nodes buried in the media. Low solar radiation of 7 MJ/m2/day enabled high cutting survival up to root initiation, after which higher radiation supported larger root and shoot production.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Aquatic ecology 24 (1990), S. 69-89 
    ISSN: 1573-5125
    Keywords: model ; eutrophication ; phosphorus ; P/C ratio ; lake ecosystem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A dynamic, deterministic model is presented to simulate the phosphorus cycle and plankton growth in the shallow, hypertrophic Loosdrecht Lakes (The Netherlands) before and after restoration measures. Besides inorganic phosphorus (SRP) in both the surface water and the interstitial water, the model comprises three algal groups, zooplankton, fish, detritus, zoobenthos and upper sediment (all modelled both in carbon and in phosphorus). Within the model system, the phosphorus cycle is completely closed. Carbon and phosphorus are described independently, so that the dynamics of the P/C ratios can be modelled. Sediment processes are described in a simplified form. Simulated values are largely within the range of observed ones. The detrital fraction of the seston (=phytoplankton+detritus) varies from 50–60% in summer to about 90% in winter. SRP in the surface water is very low during most of the year. Sensitivity for external phosphorus input is larger for algal and detrital P than for algal and detrital C and chlorophyll-a. So the P/C ratio of the seston decreases following restoration measures, as is observed in the lakes, while the much higher P/C ratios of zooplankton and fish remain constant. Phosphorus mobilisation from the sediment decreases with decreasing external input. Adaptation of the model system to the reduced loading takes place within about two years. Sources of uncertainty in the model include the limited knowledge on selective grazing as well as on mortality and mineralisation processes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 1573-5176
    Keywords: seaweed ; Agardhiella ; carrageenan ; phosphorus ; cultivation ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gas liquid chromatography, chemical analyses, and infrared and13C-NMR spectroscopies indicated that phycocolloids extracted fromAgardhiella subulata had a dominant ι-carrageenan feature with less deviant ι-carrageenan and υ-carrageenan. The presence of methylated galactose and a small contamination by xylose were registered. Unattached plants were cultivated for 4 weeks in tanks receiving seawater enriched with 53.5 µM nitrate and 0 to 20 µM phosphate (Pi) week−1. The growth was phosphorus (P)-limited up to a tissue P content of 0.14 ± 0.03% dry weight. Maximal specific growth rate and carrageenan content were observed with enrichments of 6 µM Pi and 3 µM Pi, respectively. Hence carrageenan production was promoted in the range of 3–6 µM Pi. Further Pi enrichment was useless. This phenomenon, observed with P nutrition, is comparable to the ‘Neish effect’ in nitrogen nutrition studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    ISSN: 1573-8221
    Keywords: plasmid ; transception ; transcipient ; segregation ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 126 (1990), S. 115-119 
    ISSN: 1573-5036
    Keywords: inorganic P ; organic P ; P/Fe ; P/Mn ratios ; phosphorus ; rice ; silicon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A pot experiment was conducted to measure the effect of silicon on phosphorus uptake and on the growth of rice at different P levels. Rice (Oryza sativa L. cv. Akebono) was cultured in Kimura B nutrient solution without and with silicon (1.66 mM Si) and with three phosphorus levels (0.014 mM P, low; 0.21 mM, medium; and 0.70 mM, high). Shoot dry weight with Si (+Si) in solution increased with increasing P level, while shoot weight without Si (−Si) was maximum at 0.21 mM P, suggesting that +Si raised the optimum P level for rice. +Si increased shoot weight more when P was low or high than when P was medium. The concentration and amount of inorganic P in shoots increased with increasing P level. +Si did not significantly decrease P uptake by rice at 0.014 mM P, however, uptake at 0.21 and 0.70 mM P was 27 and 30 percent less than uptake with −Si, respectively. In −Si with 0.21 and 0.70 mM P, inorganic P in shoots was more than double the concentration in shoots grown in +Si solutions. The Si concentration in shoots decreased slightly with increasing P level, although Si uptake was not significantly affected by P. +Si decreased the uptake of Fe and Mn by an average of 20 and 50 percent, respectively, thus P/Mn and P/Fe ratios increased in the shoot when P was low. From the results above, the beneficial effect of Si on the growth of rice was clearly shown when P was low or high. This effect may have resulted from decreased Mn and Fe uptake, and thus increased P availability within P deficient plants, or from reduced P uptake when P was high.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 20 (1990), S. 251-264 
    ISSN: 1573-3297
    Keywords: egg-laying behavior ; Aplysia ; neuropeptides ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract TheAplysia neuroendocrine system is a particularly advantageous model for cellular and molecular studies because of the relatively small number and large size of its component neurons. In addition, numerous anatomical and physiological studies have resulted in the assignment of behavioral roles to individual identified neurons. Recombinant DNA techniques have been used to isolate the genes that encode the precursors of peptides involved in egg-laying behavior. The comparison of the egg-laying hormone (ELH) gene family within the genusAplysia reveals high homologies in the overall structure of the precursors. A well-conserved tetrabasic residue has been shown to be the first endoproteolytic cleavage site of the precursor, giving rise to two intermediates, which are differentially processed and packaged. Some members of the ELH gene family are expressed specifically in the bag cell clusters or the atrial gland, respectively, providing an opportunity to study control of gene expression at the molecular level.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 124 (1990), S. 221-225 
    ISSN: 1573-5036
    Keywords: maize ; pollen fertility ; Zea mays L. ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Zinc deficiency decreased pollen viability in maize (Zea mays L. cv. G2) grown in sand culture. On restoring normal zinc supply to zinc-deficient plants before the pollen mother cell stage of anther development, the vegetative yield of plants and pollen fertility could be recovered to a large extent, but the recovery treatment was not effective when given after the release of microspores from the tetrads. If zinc deficiency was induced prior to microsporogenesis it did not significantly affect vegetative yield and ovule fertility, but decreased the fertility of pollen grains, even of those which visibly appeared normal. If the deficiency was induced after the release of microspores from the tetrads, not only vegetative yield and ovule fertility but pollen fertility also remained unaffected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    ISSN: 1573-5036
    Keywords: aluminium ; aluminium toxicity ; Leucaena yield ; lime ; phosphorus ; phosphorus uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of lime and P addition on the amounts of soil extractable P and Al, and on the growth of the tropical legume Leucaena leucocephala were investigated in a factorial experiment under controlled climate conditions using 4 (Koronivia, Nadroloulou, Batiri, and Seqaqa) highly-weathered, acid (pH initially 3.9 to 4.9) soils from Fiji. Resin-extractable P increased with lime addition and then decreased above pH 5.5, whereas M KCl-extractable Al decreased to undetectable levels at or above pH 5.2. Plant growth was usually adversely affected at low and high pH, even in the presence of added P. The pH (in M KCl) at which maximum growth occurred in the 4 soils varied from approximately 4.4 to 5.2; values somewhat lower than those reported in the literature. Changes in dry matter yield with increasing soil pH were strongly influenced by P status and a positive lime × P interaction was obtained with 3 of the 4 soils. Above pH 5.2, liming decreased the yield of both tops and roots, for reasons which are discussed in part II. The data obtained for extractable soil P and plant P concentrations indicate that P deficiency is a major problem on these soils.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 1573-5036
    Keywords: aluminium ; aluminium toxicity ; aluminium-induced P deficiency ; chemical composition ; Leucaena ; lime ; Lolium perenne L ; perennial ryegrass ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of lime and P on the chemical composition of the tropical legume Leucaena leucocephala were studied in a controlled climate laboratory experiment using 4 (Koronivia, Nadroloulou, Batiri, and Seqaqa) highly-weathered, acid soils from Fiji. For all soils, changes in the concentration of P in the Leucaena tops followed trends similar to the yield response curve, i.e., the concentration of P was highest at the soil pH at which maximum growth occurred. The concentration of Al in plant tops increased on either side of the pH of maximum growth, but Al uptake by the whole plant (tops plus roots) declined steadily with increasing pH. Although complete major (except P) and minor nutrients were added regularly, there was variation in the uptake of nutrients with pH. Poor growth at low pH values was attributed to an Al-induced P deficiency within the plant and at high pH to a soil P deficiency and, to a smaller extent, to the increased concentration of Al in the plant tops.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 1573-5036
    Keywords: disturbance ; fertilizer ; nitrogen ; nutrient enrichment ; phosphorus ; secondary succession ; species richness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effects of annual additions of mineral N and P (100 kg ha−1) on plant species composition and annual aboveground net primary production (ANPP) were investigated during the first three years following disturbance in a semi-arid ecosystem. Additions of N reduced richness of perennial plant species during years 2 and 3, while P reduced the number of perennial species only in year 3. From year 1 to year 2, annual and biennial species richness declined in all treatments while ANPP of annual species increased greatly. Added N increased ANPP of annual species while it decreased ANPP of most perennial species relative to the unfertilized control treatment. Community similarities were higher for the control and native vegetation than for other pairs of treatments using both species presence and plant production data. Nitrogen additions have retarded but not completely arrested secondary succession in this system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    ISSN: 1573-5036
    Keywords: maize ; nutrient concentration ; nutrient availability ; root growth ; root zone temperature ; shoot growth ; shoot meristem temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Maize seedlings were grown for 10 to 20 days in either nutrient solution or in soils with or without fertilizer supply. Air temperature was kept uniform for all treatments, while root zone temperature (RZT) was varied between 12 and 24°C. In some treatments the basal part of the shoot (with apical shoot meristem and zone of leaf elongation) was lifted up to separate the indirect effects of root zone temperature on shoot growth from the direct effects of temperature on the shoot meristem. Shoot and root growth were decreased by low RZT to a similar extent irrespective of the growth medium (i.e. nutrient solution, fertilized or unfertilized soil). In all culture media Ca concentration was similar or even higher in plants grown at 12 as compared to 24°. At lower RZT concentrations of N, P and K in the shoot dry matter decreased in unfertilized soil, whereas in nutrient solution and fertilized soil only the K concentration decreased. When direct temperature effects on the shoot meristem were reduced by lifting the basal part of the shoot above the temperature-controlled root zone, shoot growth at low RZT was significantly increased in nutrient solution and fertilized soil, but not in unfertilized soil. In fertilized soil and nutrient solution at low RZT the uptake of K increased to a similar extent as plant growth, and thus shoot K concentration was not reduced by increasing shoot growth rates. In contrast, uptake of N and P was not increased, resulting in significantly decreased shoot concentrations. It is concluded that shoot growth at suboptimal RZT was limited both by a direct temperature effect on shoot activity and by a reduced nutrient supply through the roots. Nutrient concentrations in the shoot tissue at low RZT were not only influenced by availability in the substrate and dilution by growth, but also by the internal demand for growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 1573-5036
    Keywords: eucalypt ; foliar analysis ; legume ; nitrogen ; phosphorus ; plant nutrients ; plant analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The sensitivity of tissue nutrient concentrations to changes in plant age and the supply of P and N was compared between leaves and associated twigs in two forest species. In a young regrowth stand, tissues were sampled on three occasions from the mid-crown position of karri (Eucalyptus diversicolor F. Muell.) and Bossiaea laidlawiana Tovey and Morris, a major understorey legume. Leaves and twigs were also sampled from young plants of B. laidlawiana growing in a mature eucalypt stand to which P treatments had been applied. Nitrogen application increased N concentrations in twigs of karri and B. laidlawiana, but not in leaves. Phosphorus application increased P concentrations in both leaves and twigs of karri but the average increases were proportionally greater in twigs (65%) than in leaves (36%). Over the sampling period, P concentrations in leaves declined, while those in twigs were relatively stable. In B. laidlawiana, P supply also had a larger effect on P concentrations in twigs than in leaves. Addition of 200 kg P ha−1 increased average P concentrations in twigs by 109% in the regrowth stand and by 215% in the mature stand while the corresponding increases in leaves were only 11% and 27%. Concentrations of other nutrients in both species were also affected by N and P application, the most notable being a decline in the concentrations of the minor nutrients, Zn and Cu, with increased P supply. The increased N concentrations in twigs of karri, and the increased P concentrations in tissues of both species, were associated with responses of karri to added N and P, and of B. laidlawiana to added P. This indicates that tissue concentrations of N and P were generally below critical concentrations where N and P were not applied. The results show that for these species twigs may be a better tissue than leaves for diagnosing deficiencies or predicting N and P requirements. The ratio of P concentrations in twigs to P concentrations in leaves also increased with added P. It is suggested that this ratio may be a useful index if it reduces the variability caused by sampling position within the crown or genetic differences between plants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    ISSN: 1573-5036
    Keywords: ammonium ; labile organic P ; nitrate ; N mineralization ; phosphorus ; Plantago major L. ssp. pleiosperma ; soil nutrient availability ; soil nutrient pools ; spatial variation ; temporal variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract As part of a research project on the variation in life-history characteristics within a population of Plantago major L. ssp. pleiosperma, seasonal and spatial variability in the availability of macronutrients (N, P, and K) were examined on a small scale in the 0–25 cm soil depth at a primary beach plain site, embanked since 1966. On the basis of distinct differences, among other things, in plant biomass, an a priori division into three different types of microhabitat occurring in a mosaic distribution pattern was made: an overall low-lying area (subsite 1) with slightly elevated patches of 0.5 to 1.5 m in diameter (subsite 2) and rather large patches, 20 to 40 m in diameter, of sea buckthorn shrubs, with small and relatively open spots (subsite 3) in the transitional zone from lower area into scrub. All three subsite types were studied within a total area of approximately 2000 m2. Three methods of analysis were applied: an inventory survey (sampling once at the start of the growing season), an analysis of the seasonal variation (sampling at approximately monthly intervals during the period April-November), and an assessment of nitrogen mineralization potentials in the laboratory (sampling once at the beginning of the growing season). All three procedures clearly demonstrated the occurrence of differences in the availability of nutrients over very short distances, i.e. a pronounced spatial variability among subsites. Particularly the availability of N and P appeared to have increased at the subsites 2 and 3, when compared to subsite 1. This small-scale differentiation in soil properties has occurred in an essentially homogeneous parent material (e.g. in texture and carbonate content) over a period of about 20 years. Besides a spatial variability, statistically significant temporal fluctuations were observed in the availability of N, P, and K. Relative fluctuations of mineral N (as indicated by the range/mean ratio) were especially large at the subsites 2 and 3.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 1617-4623
    Keywords: Ty elements ; Saccharomyces cerevisiae ; Retrotransposon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To learn more about the variety of Ty elements capable of activating gene expression, we characterized 206 spontaneous Ty transpositions that activate the promoterless gene his3Δ4. Most of the Ty elements appear to be full-length, although a few deleted elements were recovered. Over 95% of the insertions belong to the Ty1 family, and the rest are Ty2 elements. The excessive number of Ty1 transpositions was unexpected because there are only 2-fold more Ty1 than Ty2 elements in the yeast strains used in the selection. However, there is 20-fold more Ty1 than Ty2 RNA present in these yeast strains. This difference in RNA level explains the greater number of Ty1 verses Ty2 transpositions at his3Δ4, because Ty elements transpose through an RNA intermediate. A similar association between the Ty transcript level and transpositional activation of his3Δ4 is obtained in cells expressing GAL1-promoted Ty2-H556 or Ty2-917 elements, but only if the element does not contain a marker. Genetically marked Ty2-H556NEO and-917NEO elements transpose into and activate his3Δ4 with the same efficiency as the previously characterized Ty1H3NEO element, but are underrepresented relative to the levels of TyNEO transcript. We also found that chromosomal Ty transcripts are even more abundant than previously estimated and comprise about 1% of total cellular RNA.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    ISSN: 1617-4623
    Keywords: Bacterial conjugation ; Cyanobacteria ; IncQ plasmids ; Saccharomyces cerevisiae ; DNA methylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The promiscuous IncQ plasmid pKT210 (Cmr, Smr) is efficiently transferred by transpecific conjugation from Escherichia coli to the facultatively heterotrophic cyanobacterium Synechocystis PCC6803 when mobilized by a helper plasmid coding for IncP transfer functions. The IncQ plasmid is stably maintained in the cyanobacterium as an autonomously replicating multicopy plasmid with no detectable structural alterations and can be recovered by transformation back to E. coli when using a mcrA mcrB host. Thus, the replicative host-range of IncQ plasmids extends beyond purple bacteria to the distinct procaryotic taxon of cyanobacteria, allowing the use of these small plasmids as convenient cloning vectors in Synechocystis PCC6803 and presumably also in cyanobacteria that are not amenable to genetic transformation. In contrast, an IncQ plasmid bearing the TRP1 gene of Saccharomyces cerevisiae failed to replicate when transferred to that yeast by transformation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; AR07 gene ; Chorismate mutase ; GCN4 ; Transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The gene AR07 encodes the monofunctional enzyme chorismate mutase, a branch point enzyme in the aromatic amino acid biosynthetic pathway in Saccharomyces cerevisiae. We investigated the transcription of the AR07 gene. Three 5′ ends at positions − 36, − 56 and − 73 and the 3′ end of the transcripts 146 bp downstream of the translational stop codon were mapped. As in the promoters of other aromatic amino acid biosynthetic genes, a recognition element for the GCN4 transcriptional activator of amino acid biosynthesis is located 425 base pairs (bp) upstream of the first transcriptional start point. This element binds GCN4 specifically in vitro. Northern analysis and determination of the specific enzyme activity reveals however, that the element is not sufficient to mediate transcriptional regulation by GCN4 in vivo. We thus suggest that in addition to a consensus sequence capable of binding the GCN4 protein other factors like, for example, chromatin structure, determine whether a recognition site for a transcription factor functions as an upstream activation sequence.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; Splicing ; Nuclear structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We report on the characterization of the yeast prp20-1 mutant. In this temperature-sensitive mutant, multiple steps of mRNA metabolism are affected. The prp20-1 mutant strain showed alterations in mRNA steady-state levels, defective mRNA splicing and changes in transcription initiation or termination when shifted from the permissive to the non-permissive temperature. In addition, a change in the structure of the nucleus in these cells became apparent. Electron microscopy revealed an altered structure of the nucleoplasm of prp20-1 mutant cells when grown at the no-permissive temperature that was not observed in cells grown at the permissive temperature or in wild-type cells. The wild-type PRP20 gene was isolated and sequenced. The putative PRP20 protein has a molecular weight of 52 kDa. We found that the PRP20 gene is identical to the yeast SRM1 gene (Clark and Sprague 1989). In addition, the PRP20 protein sequence shows significant sequence similarity to the human RCC1 protein (Ohtsubo et al. 1987). This protein has been implicated in the control of chromosome condensation. Based on the phenotype of the prp20-1 mutant and the observed sequence similarity to the human RCC1 protein, we postulate that the yeast PRP20 protein is involved in the control of nuclear organization.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 224 (1990), S. 111-118 
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; Translation ; Splicing ; Paromomycin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The MSS51 gene product has been previously shown to be involved in the splicing of the mitochondrial pre-mRNA of cytochrome oxidase subunit I (COX1). We show here that it is specifically required for the translation of the COX1 mRNA. Furthermore, the paromomycin-resistance mutation (P inf454 supR ) which affects the 15 S mitoribosomal RNA, interferes, directly or indirectly, with the action of the MSS51 gene product. Possible roles of the MSS51 protein on the excision of COX1 introns are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 224 (1990), S. 257-263 
    ISSN: 1617-4623
    Keywords: General Control ; Thermotolerance ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In Saccharomyces cerevisiae starvation for a single amino acid activates the transcription of a set of genes belonging to different amino acid biosynthetic pathways (General Control, GC). We show that mutants affected in GC regulation are also affected in their response to thermal stress. Moreover, growth conditions that are known to induce heat shock proteins induce the GC response. However, unlike heat shock proteins, the transcriptional activator of GC, GCN4, is not induced after a short exposure to heat, and in gcn mutant strains induction of heat resistance is normal.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 220 (1990), S. 269-276 
    ISSN: 1617-4623
    Keywords: GABA ; Saccharomyces cerevisiae ; Transcription ; DNA sequence ; Zinc finger
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The UGA3 gene of Saccharomyces cerevisiae is required for 4-aminobutyric acid (GABA)-dependent induction of the UGA1, UGA2 and UGA4 genes which encode the two GABA catabolic enzymes and a GABA-specific permease, respectively. Measurements of UGA1-specific transcripts show that induction of UGA1 correlates with accumulation of its RNA and requires a functional UGA3 gene. A 2 kb DNA fragment complementing the uga3 mutation was isolated and shown to contain the UGA3 gene. The primary structure of the UGA3 encoded protein was deduced from the DNA sequence, and contains an N-terminal, cysteine-rich motif similar in sequence to regions found in other fungal regulatory proteins and which are supposed to form zinc finger structures involved in DNA binding. Mutations were identified in the UGA3 genes isolated from uninducible and constitutive uga3 alleles. One case of intragenic complementation between two uninducible uga3 mutants is reported, indicating a possible oligomeric structure for UGA3. The role of UGA3 is discussed in relation to its genetic properties and its predicted structure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 220 (1990), S. 283-288 
    ISSN: 1617-4623
    Keywords: Chorismate mutase ; Saccharomyces cerevisiae ; Repression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Saccharomyces cerevisiae ARO7 gene was cloned by screening a wild-type gene bank for complementation of an aro7 auxotrophic mutant. In vitro mutagenesis of the isolated plasmid (pJFB1) gave several transformants resistant to levels of the phenylalanine analogue 2-thienylalanine inhibitory to the wild-type transformant. Chorismate mutase assays indicated that two of the mutants (J14-26IV6 and J14-26IV9) were resistant to feedback inhibition by tyrosine displayed by wild-type strains. Analysis of the effect of other aromatic amino acids on chorismate mutase activity showed that tryptophan counteracted this inhibition. Analysis of the effect of tyrosine in the growth medium on enzyme activity indicated that the wild-type ARO7 gene was repressed by tyrosine, a phenomenon not previously reported. Two of the 2-thienylalanine resistant mutants (J14-26IV3 and J14-26IV9) appeared to be resistant to this repression. Transcriptional analysis confirmed that the level of ARO7 transcript decreased with increasing tyrosine concentration. In stain J14-26IV9 the ARO7 transcript level was not affected. J14-26IV9, therefore, appears to be a double mutant, resistant to both feedback inhibition and repression by tyrosine.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 222 (1990), S. 87-96 
    ISSN: 1617-4623
    Keywords: Glucoamylase ; Sporulation ; Saccharomyces cerevisiae ; Saccharomyces cerevisiae var. diastaticus ; STA genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The single glucoamylase gene (SGA1) of the yeast Saccharomyces cerevisiae is expressed exclusively during the sporulation phase of the life cycle. Enzymatic studies and nucleic acid sequence comparisons have shown that the SGA1 glucoamylase is closely related to the secreted enzymes of S. cerevisiae var. diastaticus. The latter are encoded by any of three unlinked STA genes, which have been proposed to derive from the ancestral SGA1 form by genomic rearrangement. We show that the regulation of SGA1 is distinct from that of the other members of the STA gene family. SGA1 expression did not respond to STA10, the primary determinant of glucoamylase expression from STA2. Unlike STA2, SGA1 was not regulated directly by the mating type locus. Expression of SGA1 depended on the function of the MAT products in supporting sporulation and not on the formation of haploid progeny spores or on the composition of the mating type locus per se. We conclude that the STA genes acquired regulation by STA10 and MAT by the genomic rearrangements that led to their formation. This regulation is thus distinct from that of the ancestral SGA1 gene.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    ISSN: 1617-4623
    Keywords: Aspergillus nidulans ; Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; Drug resistance ; β-tubulin mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Rhizoxin, an antibiotic, exhibits potent anti-mitotic activity against most eucaryotic cells including those of higher vertebrates, plants and fungi by binding to β-tubulin. ThebenA gene of three independently isolated rhizoxin-resistant (Rhir) mutants ofAspergillus nidulans was cloned, sequenced and compared with that of the wild-type, rhizoxin-sensitive (Rhis) strain. In all three Rhir mutants, the AAC codon for Asn-100 of thebenA β-tubulin gene was altered to ATC, coding for Ile. Sequence displacement experiments confirmed that the substitution of Ile for Asn-100 confers resistance to rhizoxin in this organism. The amino acid sequences of β-tubulin surrounding the 100th amino acid residue from the N-terminus including Asn-100 are highly conserved with a few exceptions. The fission yeastSchizosaccharomyces pombe and the budding yeastSaccharomyces cerevisiae are naturally occurring Rhir organisms whose β-tubulin genes encode Ile and Val respectively at the 100th amino acid residue. The Ile-100 ofS. pombe and the Val-100 ofS. cerevisiae were altered to Asn using site-directed mutagenesis and gene displacement techniques. The resultant haploid strains of these two yeasts uniquely expressing β-tubulin (Asn-100) instead of β-tubulin (Ile-100 or Val-100) were found to be Rhis. Haploid yeast expressing β-tubulin (Asn-100) is normal except for its sensitivity to rhizoxin. These results suggest that rhizoxin resistance has a common basis in both naturally occurring species and experimentally selected mutants in the substitution of Ile or Val for Asn-100 in β-tubulin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 1617-4623
    Keywords: Rhizopus aspartic proteinase ; Splicing of intron ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The intron of the Rhizopus aspartic proteinase gene (RNAP-I) was modified by in vitro mutagenesis and examined for its splicing efficiency in Saccharomyces cerevisiae. The wild-type intron of the RNAP-I gene was not spliced at all in spite of its structural similarity to introns of S. cerevisiae. The primary transcript of the RNAP-I gene was converted to correctly translatable mRNA only when the complete consensus sequence of S. cerevisiae introns (i.e. 5″-GTATGT-----TACTAAC-----TAG-3″) was introduced into its intron, although the efficiency of splicing was low. It is also shown that transformants carrying the RNAP-I gene with the complete consensus sequence of S. cerevisiae introns produce active RNAP-I protein.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 1617-4623
    Keywords: Cochliobolus heterostrophus race T disease ; Maize cytoplasmic male sterility ; Mitochondria ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We asked whether the mitochondrial T-urf13 gene, associated with the male sterility phenotype of T cytoplasm in maize, can be expressed in Saccharomyces cerevisiae and whether this expression can mimic the effects observed in maize. We introduced the universal code equivalent of the T-urf13 gene into the S. cerevisiae nucleus by transformation and directed its translation product into mitochondria by means of a fusion with the targeting presequence from Neurospora crassa ATPase subunit 9. We show that expression of the universal code equivalent of the T-urf13 gene in the yeast nucleus does indeed mimic its effects in maize: respiratory growth of yeast is inhibited, respiration-deficient cytoplasmic mutants accumulate and NADH oxidation of isolated mitochondria is uncoupled. All these effects are observed only if the mitochondrial targeting peptide and methomyl or HmT toxin are present.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 223 (1990), S. 49-57 
    ISSN: 1617-4623
    Keywords: Neurospora crassa ; Heterologous gene expression ; Saccharomyces cerevisiae ; Domain independence ; TRP1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The trifunctional TRP1 gene from Neurospora crassa (N-TRP1) was subcloned into the yeast-Escherichia coli shuttle vector YEp13 and expressed in Saccharomyces cerevisiae. The three activities of the N-TRP1 gene product were detected in yeast mutants that lacked either N-(5′-phosphoribosyl) anthranilate (PRA) isomerase or both the glutamine amidotransferase function of anthranilate synthase and indole-3-glycerol phosphate (InGP) synthase. The protein was detected on immunoblots only as the full length 83 kda product indicating that the trifunctional gene product was expressed in yeast primarily in a fully active, undegraded form. By placing the subcloned N-TRP1 gene under the control of the inducible PHO5 promoter from yeast, the expression of all three activities was increased to more than ten fold that of wild-type yeast and the overproduced protein could be visualized by SDS-polyacrylamide gel electrophoresis of crude extract and Coomassie Blue staining. Using the expression system described the effect of selective deletion of regions of the coding sequence of the N-TRP1 gene on expression of the three activities was tested. Expression of either the F- or C-domains, catalyzing respectively the PRA isomerase or InGP synthase activities, did not depend on the presence of the other domain in the active polypeptide. Furthermore, normal dimer formation occurred with a protein active for InGP synthase in a deletion derivative lacking most of the PRA isomerase domain, ruling out the hypothesis that interaction between the active site regions for PRA isomerase and InGP synthase accounted for dimer formation in the trifunctional product.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 223 (1990), S. 97-106 
    ISSN: 1617-4623
    Keywords: Heat shock ; Saccharomyces cerevisiae ; Stationary phase ; cAMP ; Thermotolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have isolated a new small heat shock gene, HSP12, from Saccharomyces cerevisiae. It encodes a polypeptide of predicted Mr 12 kDa, with structural similarity to other small heat shock proteins. HSP12 gene expression is induced several hundred-fold by heat shock and on entry into stationary phase. HSP12 mRNA is undetectable during exponential growth in rich medium, but low levels are present when cells are grown in minimal medium. Analysis of HSP12 expression in mutants affected in cAMP-dependent protein phosphorylation suggests that the gene is regulated by cAMP as well as heat shock. A disruption of the HSP12 coding region results in the loss of an abundant 14.4 kDa protein present in heat shocked and stationary phase cells. It also leads to the induction of the heat shock response under conditions normally associated with low-level HSP12 expression. The HSP12 disruption has no observable effect on growth at various temperatures, nor on the ability to acquire thermotolerance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    ISSN: 1617-4623
    Keywords: Intrachromosomal and interchromosomal recombination ; Saccharomyces cerevisiae ; RAD18
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The frequency of intra- and interchromosomal recombination was determined in RAD18 and rad18 deletion and rad18-3 mutant strains. It was found that spontaneous interchromosomal recombination at trp5, his1, ade2, and MAT was elevated 10- to 70-fold in the rad18-3 and rad18Δ mutants as compared to the RAD + strains. On the other hand the frequencies of spontaneous intrachromosomal recombination for the his3Δ3′, his3Δ5′ and the his4C −, his4A − duplications and for heterothallic mating type switching were only marginally elevated in the rad18 deletion mutant, and recombination between ribosomal DNA repeats was only 2-fold elevated in the rad18-3 mutant. These differences may be due to a haploid versus diploid specific difference. However interchromosomal recombination was elevated 40-fold and intrachromosomal recombination was only marginally (1.5-fold) elevated in a diploid homozygous for rad18Δ, arguing against a haploid versus diploid specific difference. Possible explanations for the difference in the elevated levels of intra- versus interchromosomal spontaneous recombination are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; Transcription initiation ; ADH gene ; TATA sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The roles of the TATA element and sequences near the mRNA initiation site in specifying the location of initiation sites in Saccharomyces cerevisiae were examined, using the Schizosaccharomyces pombe ADH gene. The importance of spacing was demonstrated by analysis of a series of deletions that removed from 8–50 bp between the TATA element and ATG translation initiation site of this gene. Primer extension mapping showed that increasing deletion length is associated with a progressive shift downstream in the location of the initiation sites. The distance of a given site from the promoter affected the relative ability of the site to be utilized for initiation. For this gene, a permissive region for transcription initiation exists between 55 and 125 bases downstream of the TATA element, and a zone of 75–115 bases allows maximal usage of an initiation site. The presence of a TATA sequence was shown to be necessary in S. cerevisiae for maintaining the location of this “window” of initiation. The TATA sequence is essential for function of the gene in S. pombe. This gene, as well as the majority of the 63 S. cerevisiae genes surveyed, uses initiation sites which fit a PyAA/T(Pu) consensus. Cis-acting mutations were recovered which restored ADH activity to a deletion allele that initiates its mRNAs downstream of the ATG. DNA sequence and transcript analysis with these mutants confirmed the requirement of proper spacing and conformity of initiation sites to the PyAA/T(Pu) consensus for efficient transcript initiation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; Gene regulation ; TUF ; Pyruvate decarboxylase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The upstream activation site of the pyruvate decarboxylase gene, PDC1, of Saccharomyces cerevisiae contains an RPG box, and mediates the increase in expression of a PDC1-lacZ fusion gene during growth on glucose. Oligonucleotide replacement experiments indicate that the RPG box functions as an absolute activator of expression, but other elements (possibly CTTCC repeats) are required for carbon source regulation, and maximal expression. Gel retardation and oligonucleotide competition experiments suggest that the DNA binding factor TUF interacts with the RPG box in the upstream region of PDC1. Binding of TUF factor is not carbon source dependent in in vitro experiments, and is probably not responsible for glucose induction of PDC1 expression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    ISSN: 1573-5036
    Keywords: maize ; sorghum ; spore production ; VAM fungi ; water-stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Maize (Zea mays) and sorghum (Sorghum bicolor) were inoculated with a range of VAM fungi and grown under water-stressed and unstressed conditions. There was considerable variation amongst the inocula in their effects on plant growth. Inoculation with Glomus clarum produced the biggest plants in each host, with Glomus monosporum and Acaulospora sp. giving the least growth overall. Root infection produced by the different inocula also varied, but levels were not correlated with effects on plant growth. Water-stress reduced plant growth, with the effects not being altered by mycorrhizal infection. VAM infection levels were not affected by water-stress. Spore production from most inocula was reduced by water-stress, both in total spore numbers and in terms of spores per gram plant weight. Sporulation of G. clarum, G. epigeum and G. monosporum were affected less by stress than were the other inocula. Spore production was in general greater on sorghum than on maize, but the host effect varied amongst the inocula.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 127 (1990), S. 237-241 
    ISSN: 1573-5036
    Keywords: Fusarium moniliforme ; Macrophomina phaseolina ; maize ; organic amendment ; stalk rot
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Five organic materials, Calopogonium sp. leaves, rice straw, mixed wood saw dust of Terminalia sp. Triplochyton sp. and Kaya sp., fresh guinea grass and poultry manure were added to soil with a recent history of high stalk rot of maize caused by Macrophomina phaseolina and Fusarium moniliforme. The two stalk rot organisms reacted differently to the organic amendments. All the amendments produced significantly less Fusarium stalk rot disease than the unamended control. Amendment of soil with fresh Calopogonium leaves was almost ineffective in controlling the incidence of Macrophomina phaseolina. Organic amendment with poultry manure increased the disease casued by M. phaseolina. The other amendments appeared to be equally effective in checking the disease. Increased microbial population due to amendment may play some role in disease suppression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 1573-5036
    Keywords: crop rotations ; copper ; fertilizers ; iron ; manganese ; phosphorus ; potassium ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A field experiment was carried out to study the effect of various crop rotations, of high yielding varieties of cereals, pulses, fodders, tubers and oilseeds, on the performance of the crops and the fertility status of the soil over two crop-rotation cycles. The yields of rice (Oryza saliva L.), potato (Solanum tuberosum L.) and onion (Allium cepa) crops were found to be decreasing. The yields of wheat (Triticum aestivum L.) and mustard (Brassica juncea coss), were not affected, while the yield of moong (Phaseolus aureus Roxb.) showed a tendency to increase. Rotations which included berseem (Trifolium alexandrinum) increased the organic carbon content of the soil and there was a slight lowering of the pH with the highest application of phosphatic fertilizer. The accumulation of available potassium was greater in the treatments where the highest amount of fertilizer was applied. The available nitrogen content of the soil increased with application of nitrogen and the balance sheet of nitrogen, phosphorus and potassium showed a positive trend. The continuous cropping of high yielding varieties showed a reduction in the available zinc and iron status of the soil, whereas available manganese and copper increased. The available micronutrients, except manganese, did not correlate significantly with soil pH.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 125 (1990), S. 7-18 
    ISSN: 1573-5036
    Keywords: aluminum ; ectomycorrhizae ; phosphorus ; Pinus rigida ; Pisolithus tinctorius ; sand culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Aluminum (Al) in the rhizosphere adversely affects plant nutrition and growth. Although many conifer species, and pitch pine (Pinus rigida) in particular, have evolved on acidic soils where soluble Al is often high, controlled environment studies often indicate that Al interferes with seedling growth and nutrient relations. Under normal field conditions, conifer roots grow in a symbiotic relationship with ectomycorrhizal fungi, and this association may modulate the effects of Al on root physiology. To investigate the influence of mycorrhizal infection on Al toxicity, pitch pine seedlings were grown with or without the ectomycorrhizal symbiont Pisolithus tinctorius and were exposed to low levels of Al in sand culture. Aluminum at 50 μM reduced nonmycorrhizal seedling growth and increased foliar Al concentrations, but did not alter photosynthetic gas exchange or other aspects of seedling nutrition. Nonmycorrhizal seedlings exposed to 200 μM Al exhibited decreased growth, increased transpiration rates, decreased water use efficiency, increased foliar Al and Na levels, and reduced foliar P concentrations. Seedlings inoculated with P. tinctorius exhibited unaltered growth, physiological function, and ionic relations when exposed to Al. The fungal symbiont evidently modulated ionic relations in the rhizosphere, reducing Al-P precipitation reactions, Al uptake, and subsequent root and shoot tissue Al exposure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 46 (1990), S. 237-247 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; genetic variation ; prediction ; dry matter yield ; early vigour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Evidence of genetic variation for early vigour is presented using maize line × tester crosses. The leaf appearance rate and associated variance components are affected by a physiological stress attributable to the transition to autotrophic nutrition by the plant. At this stage, specific combining ability plays an important role in the total genetic variation. It is concluded that differing genetic controls exist in early and late material, and that this difference is also manifested in leaf initiation and elongation rates. The ground coverage rate, as a component of plant development, is genetically correlated to total dry matter yield. The genetic correlations vary according to the growth stage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; forage ; digestibility ; near infrared reflectance spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Near infrared reflectance spectroscopy (NIRS) is emerging as a potentially useful tool in breeding plants for quality traits. Information is lacking, however, on its use in forage maize (Zea mays L.). The objectives of the present investigation were to evaluate the prediction of digestibility traits of maize stover using NIRS technique and to study the effect of laboratory (Lab) and NIRS assays on the estimates of variation and covariation. Twelve inbred lines, 66 diallel crosses among them and eight hybrid checks were evaluated at silage and grain harvests for 2 years at two agro-climatically diverse locations in the Federal Republic of Germany. Standard methods were used for Lab analysis of in vitro digestible organic matter (IVDOM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL). In NIRS evaluation, calibration equations were developed by modified stepwise regression. The standard error of calibration was 2.5, 1.7, 1.4 and 0.4 for IVDOM, NDF, ADF and ADL, respectively. The coefficient of multiple determination was high (≥0.9) except for ADL. The validation statistics (standard error and correlation coefficient) were similar. In the diallel crosses, the estimates of variation (heritabilities in broad and narrow sense, genotypic and error coefficients of variation), generally, did not vary appreciably and consistently in the comparisons between Lab and NIRS methods particulary at silage harvest. Simple and rank correlations between Lab and NIRS analyses were positive and significant. These correlation coefficients based on the mean performance of the diallel crosses at silage harvest were 〉0.9 and at least 16 hybrids were common between the two analyses, among the upper one-third or lower one-third (22) hybrids. The study showed that NIRS analysis should be useful in maize breeding programmes wherein a large number of genotypes need to be evaluated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 48 (1990), S. 63-72 
    ISSN: 1573-5060
    Keywords: Zea mays ; maize ; corn ; yield ; kernel weight ; shelling percentage ; plant height ; ear height ; husk weight ; cob weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary White-endosperm (y y y) maize (Zea mays L.) is vital to the maize dry-milling industry. However, a substantially greater acreage in the U.S.A. is planted to yellow (Y Y Y) than white maize. Data on comparative performance of yellow and white maize is scanty, and results are inconclusive. This field study was conducted to provide information on dosage effects of y gene on grain yield, 500-kernel (K) weight, shelling percentage, plant and ear height, and cob weight. Yellow x yellow, yellow x white, and white x white endosperm crosses were made among five yellow and five white endosperm lines of Mo14W × Oh7B parentage. In the material studied, the genetic complement of the white-endosperm parent Mo14W varied from 12.50% to 87.50% across 15 treatments. The effect of Mo14W dosages among treatments was removed through analysis of covariance. If differences among treatment means existed, they were attributed to the y gene. A test of parallelism among regression coefficients (Ho. β1=β2=---β15=βc) indicated that these regressions coefficients for plant height, ear height, 500-K weight, and husk weight showed parallelism across yellow x yellow, yellow x white, and white x white crosses. Differences in plant height were significant in 3 out of 5 comparisons each between Y Y vs. y y, Y y vs. y y, and Y Y vs. Y y. Differences in ear height were significant in 1 of 5 Y Y vs. y y comparisons, in 3 of 5 Y y vs. y y comparisons, and in 1 of 5 Y Y vs. Y y comparisons. Differences in 500-K weight were significant in 4 of 5 Y Y vs. y y, in 2 of 5 Y Y vs. Y y and in 1 of 5 Y y vs. y y comparisons. Differences in husk weight were significant in all the Y Y vs. y y comparisons, in 4 of 5 Y y vs. y y comparisons, and in 1 of 5 Y Y vs. Y y comparisons. An increase in the y gene dosage caused, in general, a significant decrease in grain yield, 500-K weight, plant height, ear height, and husk weight. Shelling percentage was decreased but not appreciably. The Y y combination had a heterotic effect on plant height, ear height, and cob weight. An implication of the findings of this study is that it would be difficult to breed for high-yielding white maize if one used this y gene source. At this time, this is the only source (chromosome 6) available for white-endosperm maize. Non-parrallelism among regression coefficients was noted for shelling percentage, grain yield, and cob weight. Non-parallelism was observed in shelling percentage of the yellow x yellow crosses, cob weight of the yellow x white crosses and in grain yield of both yellow x yellow and yellow x white crosses. In general, an increase in mean Mo14W dosage resulted in increased grain yield. Mo14W dosages generally reduced cob weight in the yellow x white crosses. Shelling percentage increased as the mean Mo14W dosages increased for the yellow x yellow crosses. An increase in Mo14W dosages resulted in an increase in 500-K weight.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 122 (1990), S. 107-114 
    ISSN: 1573-5036
    Keywords: aseptic ; 14C-labelled ; carbohydrate ; decomposition ; root exudate ; maize ; monosaccharides ; root lysate ; sandy loam sonication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Maize (Zea mays var. Caldera) plants were grown under sterile and not sterile conditions in soil in an atmosphere continuously enriched with14CO2 for 36 days. At harvest the above ground parts of the maize were cut off and the roots were separated from the soil by washing with water. The soil was dispersed using ultrasonics and separated into soluble clay silt and sand fraction. Roots were included in the coarse sand fraction. 25% of the total label present in the soil ≡ 5.5% of that in the soil-plant system, was water soluble. Very little label was present in the clay and silt fractions (5% in each) and most (65%) was in the sand fraction as root material. Rapid extraction of soil after the removal of roots without ultrasonic treatment released soluble matter which amounted to 〈0.5% of the total activity in the soil-plant system. Isolated roots steeped in water released about 18% of their activity. Much of the soluble fraction may therefore be root lysate. The soil and roots accounted for 22% of the total activity in the soil-plant system. Glucose accounted for 89% of the sugars in the soluble fraction of the soil. 78% or more of the14C present in glucose, arabinose and xylose constituents of the root-soil mixture occurred in the coarse and fine sand fractions, which also included root material. For mannose and galactose the value was 70% and for rhamnose, 50%. After reinoculation of the soil-root mixture and decomposition for 56 weeks, the water soluble material obtained on fractionation of the soil decreased to less than 1% of the total activity. A much greater proportion, 25%, was present in the clay fraction as a result of decomposition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    ISSN: 1573-5036
    Keywords: aluminum ; liming ; phosphorus ; Stylosanthes guianensis ; tropical soil ; vesiculararbuscular mycorrhiza
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of 3 different species of vesicular-arbuscular mycorrhizal fungi on the growth of Stylosanthes guianensis (Aubl.) Sw. cultivated in a sterilized acid and dystrophic soil (Quartzipsament), with 4 levels of lime (0; 0.27; 0.63 and 1.10 meq Ca2+/100 g air-dried soil, as Ca(OH)2) and 2 P levels (0 and 20 mg P/kg soil, as KH2PO4) was evaluated under greenhouse conditions. Plants were harvested 40, 60, and 80 days after planting. Stylosanthes guianensis was highly mycotrophic, especially in soil without P fertilization. Mycotrophism was highest in plants inoculated with Acaulospora scrobiculata in soil receiving no P fertilizer and with 0.63 meq Ca2+/100 g air-dried soil. Shoot growth increment was as high as 5129% at the third harvest. Inoculation with Glomus macrocarpum presented intermediate results, whereas inoculation with Gigaspora margarita had no significant effect on plant growth. Root per cent colonization and shoot dry weight, as well as root percent colonization and shoot to root ratio were significantly correlated. The occurrence of S. guianensis in very acid and dystropic soils, containing toxic levels of Al3+, requires the association with VAM fungi for the plant tolerate such conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    ISSN: 1573-5036
    Keywords: buried bag incubation ; leguminous green manures ; maize ; N mineralization ; N supplying potential ; N uptake ; Oxisol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A buried bag incubation technique was proposed to monitor N release from soil and decomposing green manure. The technique would facilitate not only the screening of legumes as sources of N but also measurement of the N supplying capacity of soils. Several tropical legumes were incorporated into field plots followed either by maize (Zea mays L.) or by bare fallow. Soil samples from the plow layer containing the incorporated green manure were placed in low density polyethylene bags and buried within the plow layer under the maize crop for in situ incubation. Periodic withdrawal of the bags was accompanied by fallow soil profile sampling. Above ground N accumulation by maize was equally well correlated to N release measured by either method although the bag technique required much less labor. Supplemental experiments suggested that N accumulation in the bags was reduced due to inadequate O2 diffusion but only when O2 demand was high and soil water potential was high. The results show that in situ bag incubation alone or together with fallow soil sampling can be used to estimate the N supplying potential of soil and leguminous residues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    ISSN: 1573-5036
    Keywords: calcium ; copper ; desert ; ground water ; iron ; magnesium ; manganese ; nitrogen ; phosphorus ; Prosopis glandulosa ; rooting patterns ; sodium ; symbiotic nitrogen fixation ; trace metals ; water table ; water use efficiency ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Mesquite plants (Prosopis glandulosa var. Torreyana) were grown in 2-m long columns 20 cm in diameter, and provided with a constant, stable ground water source 10 cm above the sealed base of the column. Ground water contained 0, 1 or 5 mM nitrate, or a mixed salt solution (1.4, 2.8, or 5.6 dS m-1) with the ionic ratios of ground water found in a field stand of Prosopis at Harper's Well (2.8 dS m-1). Water uptake in the highly salinized columns began to decrease relative to low salt columns when soil salinity probes 30 cm above the column base read approximately 28 dS m-1, a potential threshold for mesquite salt tolerance. Prosopis growth increased with increasing nitrate, and decreased with increasing salinity. Water use efficiency was little affected by treatment, averaging approximately 2 g dry matter L-1 water used. Most fine roots were recovered from a zone about 25 cm above the ground water surface where water content and aeration appeared to be optimal for root growth. Root-shoot ratio was little affected by nitrate, but increased slightly with increasing salinity. Plant tissue P concentrations tended to increase with increasing salinity and decrease with increasing N, approaching potentially deficient foliage concentrations at 5 mM nitrate. The whole-plant leaf samples increased in sodium concentration both with added salt and with added nitrate. Foliar manganese concentrations increased with increasing salt in the absence of nitrate. Concentrations of sodium in leaves were low (〈10 g kg-1), considering the high salt concentrations in the ground water. Prosopis appears to exclude sodium very effectively, especially from its younger leaves. Although Prosopis is highly salt tolerant, the degree to which it utilizes soil nitrate in place of biologically fixed N may lower its salinity tolerance and affect its nutrient relations in phreatic environments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 123 (1990), S. 83-88 
    ISSN: 1573-5036
    Keywords: maize ; nitrogen availability tests ; soil nitrate ; UV absorbance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The ability of several chemical soil N availability indexes to predict the N supplying capability (NSC) of soils to maize in the field was evaluated in 49 field experiments over 3 years in Pennsylvania. Two recently proposed indexes based on the amount of NH4 + released by treating soil with 2 M KCl at 100°C for 4 hr or with a pH 11.2 phosphate-borate buffer for 8 min were not good predictors of NSC (r=0.484 and 0.254, respectively). The absorbance of a 0.01 M NaHCO3 extract at 260 nm was also poorly correlated with field-measured NSC (r=0.412). The pre-sidedress soil NO3 − test (PSNT), the soil NO3 − concertration in the surface 20 cm of soil at planting, and the UV absorbance at 200 nm of a 0.01 M NaHCO3 extract of at planting soils were all moderately well correlated with NSC (r=0.672, 0.750, and 0.737, respectively). The latter two indexes are very simple, rapid, and inexpensive to perform and offer the possibility of improving the prediction of NSC in heavily manured fields.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 123 (1990), S. 95-100 
    ISSN: 1573-5036
    Keywords: Belonolaimus longicaudatus ; Criconemella sphaerocephala ; maize ; Meloidogyne incognita ; nematode ; Paratrichodorus minor ; plant-parasitic nematodes ; Pratylenchus brachyurus ; sampling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Distribution of plant-parasitic nematode species at soil depths of 0–15 cm, 15–30 cm, and 30–45 cm was examined in two maize fields in Florida during 1987 and 1988. Soil type in both fields was an Arredondo fine sand, consisting of 94–96% sand at all three depths. On most sampling dates, more than 50% of the Belonolaimus longicaudatus collected occurred at the 0–15 cm depth. Only 20–30% of Criconemella sphaerocephala were present at this depth, and the depth distribution of this nematode differed in the two fields. The greatest densities of Pratylenchus brachyurus often occurred at 15–30 cm. Vertical distributions of Meloidogyne incognita and Paratrichodorus minor were erratic and showed marked seasonal variation. For all species examined except B. longicaudatus, a diagnostic soil sample collected 15 cm deep would recover only a minority of the nematode population present in the soil profile.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 1573-5036
    Keywords: barley ; chlorosis resistance ; cucumber ; genotypical differences ; grasses ; iron mobilization ; iron uptake ; maize ; microorganisms ; oat ; phytosiderophores ; rice ; root exudates ; root growth ; rye ; sorghum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Graminaceous species can enhance iron (Fe) acquisition from sparingly soluble inorganic Fe(III) compounds by release of phytosiderophores (PS) which mobilize Fe(III) by chelation. In most graminaceous species Fe deficiency increases the rate of PS release from roots by a factor of 10–20, but in some species, for example sorghum, this increase is much less. The chemical nature of PS can differ between species and even cultivars. The various PS are similarly effective as the microbial siderophore Desferal (ferrioxamine B methane sulfonate) in mobilizing Fe(III) from a calcareous soil. Under the same conditions the synthetic chelator DTPA (diaethylenetriamine pentaacetic acid) is ineffective. The rate of Fe(III)PS uptake by roots of graminaceous species increases by a factor of about 5 under Fe deficiency. In contrast, uptake of Fe from both synthetic and microbial Fe(III) chelates is much lower and not affected by the Fe nutritional status of the plants. This indicates that in graminaceous species under Fe deficiency a specific uptake system for FePS is activated. In contrast, the specific uptake system for FePS is absent in dicots. In a given graminaceous species the uptake rates of the various FePS are similar, but vary between species by a factor of upto 3. In sorghum, despite the low rate of PS release, the rate of FePS uptake is particularly high. The results indicate that release of PS and subsequent uptake of FePS are under different genetic control. The high susceptibility of sorghum to Fe deficiency (‘lime-chlorosis’) is most probably caused by low rates of PS release in the early seedling stage. Therefore in sorghum, and presumably other graminaceous species also, an increase in resistance to ‘lime chlorosis’ could be best achieved by breeding for cultivars with high rates of PS release. In corresponding screening procedures attention should be paid to the effects of iron nutritional status and daytime on PS release as well as on rapid microbial degradation of PS.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...