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
  • Nicotiana  (17)
  • Springer  (17)
  • Blackwell Publishing Ltd
  • Institute of Physics
  • 1975-1979  (17)
  • 1950-1954
  • 1978  (17)
Collection
Publisher
  • Springer  (17)
  • Blackwell Publishing Ltd
  • Institute of Physics
Years
  • 1975-1979  (17)
  • 1950-1954
Year
  • 1
    ISSN: 1432-2048
    Keywords: Antirrhinum ; Cellulose ; Nicotiana ; Protoplasts ; Scanning microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The formation of cell wall fibres at the surface of isolated leaf protoplasts has been studied by scanning electron microscopy. Fibres are not formed on incubated protoplasts until a lag period has elapsed. This period is about 8 h for leaf protoplasts of Nicotiana tabacum and about 45 h for leaf protoplasts of Antirrhinum majus. In the case of Antirrhinum protoplasts the length of the lag period is dependent on the concentration of osmoticum present during the incubation period. If regenerating protoplasts are briefly treated with dilute cellulase, the newly formed wall is completely digested. Such protoplasts are capable of producing new fibres at the surface within minutes of their return to a nutrient medium. These results are discussed in terms of the likely source of the lag period and its significance in wall regeneration studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Planta 139 (1978), S. 155-158 
    ISSN: 1432-2048
    Keywords: Avena ; Cell-wall regeneration ; Electrical potential ; Nicotiana ; Protoplast culture ; Turgor pressure ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four independent kinds of observations indicate that the cell wall regenerated by oat (Avena sativa L.) and corn (Zea mays L.) protoplasts in culture is less well developed than that regenerated by tobacco (Nicotiana tabacum L.) protoplasts. Following wall regeneration the cereal protoplasts remained susceptible to osmotic shock upon transfer to water, showed great enlargement, stained poorly with calcofluor white, and maintained a positive internal electrical potential. The development of a negative membrane potential by tobacco protoplasts in culture often occurred simultaneously with the onset of cell division. Since division was observed only in protoplasts which had regenerated good cell walls and had re-established negative membrane potentials it is suggested that culture conditions which favor these two processes should improve protoplast viability.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Planta 140 (1978), S. 293-294 
    ISSN: 1432-2048
    Keywords: Callus culture ; DPX-3778 ; Nicotiana ; Tissue culture ; Triazinone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract DPX-3778, the triethanolamine salt of 3-(p-chlorophenyl)-6-methoxy-s-triazine-2,4(1H,3H) dione, at concentrations of 0.124–2.48 μM enhanced ca. 4-5-fold the proliferation of tobacco (Nicotiana tabacum L. cv. Wisconsin 38) callus cultured in the presence of indole-3-acetic acid and kinetin, and retarded its senescence.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-2048
    Keywords: Hypersensitivity ; Nicotiana ; o-Diphenols ; O-Methyltransferases ; Tobacco mosaic virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three distinct o-diphenol O-methyltransferases (OMTs) were found in leaves of Nicotiana tabacum, variety Samsun NN. They could be clearly distinguished by differences in elution pattern upon chromatography on DEAE-cellulose and in specificity towards 16 diphenolic substrates. The phenylpropanoids caffeic acid and 5-hydroxyferulic acid, whose importance as lignin precursors is well known, were the best substrates of OMT I, but they were also efficiently methylated by the two other OMTs that showed a broader substrate specificity. The highest rates of methylation were observed by assaying these latter enzymes with catechol, homocatechol and protocatechuic aldehyde. The flavonoid quercetin, the major o-diphenol of tobacco leaves, was a good substrate for OMTs II and III, but was also methylated significantly by OMT I. The tobacco OMTs showed both para-and meta-directing activities with protocatechuic acid, protocatechuic aldehyde and esculetin as substrates. Para-O-methylation of the former substrate arose almost exclusively from OMT I whereas that of the two latter substrates from all three enzymes. In healthy leaves the total O-methylating activity varied very much with the batch of plants whereas the relative contributions of the three enzymes were rather constant. On an average, OMTs I, II and III acounted towards caffeic acid, respectively. In tobacco mosaic virus-infected leaves carrying local necrotic lesions we found the same three OMTs with the same substrate specificities, but with increased activities. The degree of stimulation of both OMTs II and III was 2–3 times greater than that of OMT I when the leaves had a moderate number of lesions, and 3–5 times greater with large number of lesions. It is very likely that the changes in both the pattern of the O-methylating enzymes and the concentrations of the naturally occuring o-diphenolic substrates are related to an increased biosynthesis of lignins and of lignin-like compounds. These aromatic polymers could be involved in the cell wall thickening associated with the hypersensitive reaction and with the resistance to virus spread that occur in the cells surrounding the local lesions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-2048
    Keywords: Cell wall formation ; Cytokinesis ; Inhibitors ; Mitosis ; Nicotiana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of cytochalasin B, colchicine, coumarin and 2,6-dichlorobenzonitrile on cell wall formation and cellular division was studied by light and electron microscopy with tobacco mesophyll protoplasts cultivated in vitro. 2,6-dichlorobenzonitrile was found to be the most effective and reversible inhibitor of cell wall formation. The other inhibitors caused irreversible damage and/or inhibited mitosis. In protoplasts cultivated in the presence of 2,6-dichlorobenzonitrile the total inhibition of cell wall formation had no effect on nuclear division, but cytokinesis was totally inhibited so that multinucleate protoplasts were obtained.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Planta 143 (1978), S. 29-32 
    ISSN: 1432-2048
    Keywords: Hybrids (somatic) ; Isoenzymes ; Kanamycin resistance ; Nicotiana ; Somatic hybrids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fusion of Nicotiana knightiana Goodsp. and kanamycin resistant Nicotiana sylvestris Speg. et Com. protoplasts was induced by polyethylene glycol treatment. Heterokaryons were isolated by micropipette and transferred to nurse cultures of albino cells. Colonies originating from the heterokaryons could subsequently be distinguished by their green colour. The somatic hybrid nature of four such colonies was confirmed by isoenzyme pattern, kanamycin resistance and restored morphogenic potential. An additional kanamycin resistant line with characteristic Nicotiana knightiana isoenzymes was also found indicating that the drug resistance in the kanamycin resistant parent is under cytoplasmic control.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Planta 141 (1978), S. 77-82 
    ISSN: 1432-2048
    Keywords: Cell wall ; myo-Inositol ; Nicotiana ; Polysaccharides (cell wall) ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tobacco (Nicotiana tabacum L.) cells were cultured in a liquid medium which contained sucrose as a source of carbon and energy. Various cell-wall constituents and wall precursors (L-arabinose, D-xylose, D-galactose, D-mannose, D-glucuronate, myo-inositol) were added to cells growing in this medium to by-pass possible rate-limiting steps in the relevant metabolic pathways. None of these compounds stimulated growth as measured by increase in fresh weight; myo-inositol did cause a slight increase and L-arabinose a decrease in dry weight accumulation compared to controls grown on sucrose only. Although myo-inositol was not needed for rapid growth, tracer level amounts of [2-3H]myo-inositol were rapidly absorbed and metabolized. Label was incorporated into the uronide and pentose residues of cell walls and exocellular polysaccharide.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Planta 142 (1978), S. 235-238 
    ISSN: 1432-2048
    Keywords: Brassica ; Cell-cell interaction ; Nicotiana ; Petunia ; Protoplasts (surface charge) ; Vigna
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract ζ-potential of mesophyll protoplasts of tobacco (Nicotiana tabacum L.), petunia (Petunia hybrida Hort.), turnip (Brassica rapa L.) and cowpea (Vigna unguiculata L. Walpers) was determined by use of a cell electrophoresis apparatus. All protoplasts examined showed a constant negative value of-10 to-35 mV. The addition of CaCl2 nullified the ζ-potential of tobacco protoplasts. This phenomenon is explained by DLVO theory of colloid science, which has been successfully applied to animal cells. Furthermore, positively charged polymers reversed the ζ-potential to positive values. Treatment of the protoplast surface with several enzymes was carried out to characterize the chemical nature of suface charges. The removal of surface charges was most conspicuous by the treatment of acid phosphatase (EC 3.1.3.2), but did not occur upon treatment with α-neuraminidase (EC 3.2.1.18) or Streptomyces griseus pronase. Thus a major part of the surface charge originates from the phosphate groups at the cell membrane. The significance of these studies for the properties of the protoplast surface in cell adhesion is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Planta 138 (1978), S. 299-301 
    ISSN: 1432-2048
    Keywords: Bryophytes ; Funaria ; Nicotiana ; Protein pattern ; Pteridophytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Soluble proteins extracted with Tris-buffer pH 8.8 from different mosses are analysed by microgelelectrophoretic method for comparison to the specific proteins present only in the caulonema of Funaria hygrometrica. The protein patterns are also compared with those of liverwort, fern gametophytes and sporophytes and tobacco. It is observed that the “caulonema specific proteins” are only present in the caulonema of these mosses and are absent in other plants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-2048
    Keywords: Cell wall ; Cellulose ; Lycopersicum ; Nicotiana ; Plasmalemmasomes ; Plasma membrane ; Protoplasts ; Raphanus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Freeze-etch observations of protoplasts isolated from tobacco (Nicotiana tabacum L.) mesophyll tissue and tomato (Lycopersicum esculentum Mill.) fruit locule tissue are described which clarify earlier observations (Burgess, J., Fleming, E.N., Planta 131, 173–178, 1976; Planta 133, 267–273, 1977), obtained using scanning electron microscopy. of “fibres” associated with “projections” from these cell surfaces. It is demonstrated (1) that the “fibres” consist of bundles of small numbers of microfibrils which have become artifactually thickened by the deposition of coating materials, and (2) that the apparent association between “fibres” and “projections” results from microfibrils being lifted preferentially from protoplast surfaces in regions rich in “projections” (plasmalemmasomes). With the higher resolution available using freeze-etching it can be demonstrated that microfibril deposition does not occur in discontinuous zones on these protoplast surfaces. Globules associated with microfibril termini in radish (Raphanus sativus L.) roots are illustrated and it is proposed that turgor pressure differences between isolated protoplasts and intact tissue may account for the absence of similar globules from isolated protoplast surfaces.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 1432-2048
    Keywords: Nucleic acid synthesis ; Nicotiana ; Osmotic stress ; Protein synthesis ; Protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The incorporation of labeled precursors into RNAs and proteins of isolated tobacco (Nicotiana tabacum L.) leaf protoplasts decreases with increasing osmotic pressure in the incubation medium. The incorporation of precursors into RNA and proteins is linear for 15–18 h after the isolation of the protoplasts, irrespective of the osmolarity of the culture media. The uptake of precursors is also affected by the osmolarity of the medium. However, the osmotic stress-induced inhibition of incorporation of precursors into RNA and proteins is also apparent if the differences in uptake are taken into consideration in the calculation. Incorporation of 32P into TMV-RNA is also inhibited by osmotic stress. As assayed by the double labeling ratio technique, osmotic stress has less unequivocal effect on TMV protein synthesis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-2048
    Keywords: Cell cultures ; Medicago ; Nicotiana ; Nitrogen sources ; TCA cycle ; Tissue culture ; Triticum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Alfalfa (Medicago sativa L. cv. Canadian No. 1), tobacco (Nicotiana tabacum L. var. humilis) and wheat (triticum monococcum L.) cells were grown in a defined, liquid medium containing either ammonium sulfate, L-glutamine or potassium nitrate as the sole nitrogen source, and the effects of the tricarboxylic-acid (TCA) intermediates, citrate and α-ketoglutarate (5, 10, 15 mM), on the growth (dry-weight increase) of these cells was observed. The three cell suspension cultures exhibited a different growth response to the TCA-cycle intermediate supplied, depending upon the concentration of the additive and the nitrogen source. Citrate (5 mM) greatly enhanced growth of alfalfa and wheat cells in an ammonium-based medium but was less effective at higher concentrations, and in the case of alfalfa cells markedly inhibited growth. Tobacco cell growth was inhibited by all citrate concentrations tested. In contrast, all concentrations of α-ketoglutarate used stimulated the growth of all three cell cultures in an ammonium-based medium. Alfalfa and wheat cells grown in an L-glutamine-based medium were influenced by citrate in a manner similar to that in ammonium-based medium. The growth of tobacco cells was slightly enhanced by 5 mM citrate but inhibited by higher concentrations. α-Ketoglutarate, at all concentrations tested, was stimulatory to the growth of the cells of all three species in a glutamine-based medium, except for alfalfa cells which were inhibited at 15 mM. Both TCA-cycle acids inhibited the growth of alfalfa and tobacco cells grown on a nitrate-based medium whereas the growth of wheat cells was almost unaffected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1432-2048
    Keywords: Anabaena ; Cell uptake ; Cyanobacterium ; Nicotiana ; Polyethylene glycol ; Protoplast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Auxotrophic cells of the filamentous cyanobacterium Anabaena variabilis Kütz. were introduced into protoplasts of Nicotiana tabacum L. in an attempt to engineer a nitrogen-fixing endosymbiosis. Conditions were established to maximize uptake of the cyanobacteria by use of polyethylene glycol. Culture of the novel association was not successful: tobacco protoplasts with Anabaena inside did not appear to divide. Most of the protoplasts expelled the cyanobacteria and simultaneously disintegrated. The reasons for the incompatibility are not known.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 53 (1978), S. 49-55 
    ISSN: 1432-2242
    Keywords: Density gradient ; Nicotiana ; Protoplasts ; Selection ; Somatic hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Buoyant density differences between different types of protoplasts were used in an iso-osmotic density gradient system to enrich protoplast fusion mixtures for heterokaryocytes. Protoplasts of maize stem and wheat mesophyll, as well as epidermis, stem parenchyma and mesophyll protoplasts of two amphihaploid, light sensitive tobacco mutants were fused with polyethylene glycol using conventional methods and a new rolling tube technique. The protoplast combinations used for fusion involved protoplast types with considerably different buoyant densities. Enriched fractions of maize-wheat heterokaryocytes of intermediate density were recovered which contained up to 31% mostly binucleate heterokaryocytes (a 2–7 fold relative enrichment). Tobacco heterokaryocytes recovered analogously from enriched intermediate fractions readily divided and gave rise to an increased number of light resistant calluses when compared with cultures from non-fractionated fusion mixtures. Maize-wheat fusion products, however, failed to divide.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 53 (1978), S. 49-55 
    ISSN: 1432-2242
    Keywords: Density gradient ; Nicotiana ; Protoplasts ; Selection ; Somatic hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Buoyant density differences between different types of protoplasts were used in an iso-osmotic density gradient system to enrich protoplast fusion mixtures for heterokaryocytes. Protoplasts of maize stem and wheat mesophyll, as well as epidermis, stem parenchyma and mesophyll protoplasts of two amphihaploid, light sensitive tobacco mutants were fused with polyethylene glycol using conventional methods and a new rolling tube technique. The protoplast combinations used for fusion involved protoplast types with considerably different buoyant densities. Enriched fractions of maize-wheat heterokaryocytes of intermediate density were recovered which contained up to 31% mostly binucleate heterokaryocytes (a 2–7 fold relative enrichment). Tobacco heterokaryocytes recovered analogously from enriched intermediate fractions readily divided and gave rise to an increased number of light resistant calluses when compared with cultures from non-fractionated fusion mixtures. Maize-wheat fusion products, however, failed to divide.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 129 (1978), S. 177-183 
    ISSN: 1615-6110
    Keywords: Solanaceae ; Nicotiana ; Fraction I protein ; interspecific hybrids ; allopolyploids ; serotaxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The serological reactions of Fraction I proteins from interspecific hybrids in the genusNicotiana have been examined by immunodiffusion in agar gels using antisera to crystalline Fraction I proteins fromN. glutinosa, N. gossei, andN. tabacum. The serological reactions of the proteins from the hybrids resembled the reactions of the proteins from the maternal parent species but not from the paternal species. Changes in ploidy level did not affect the serological reactions of Fraction I proteins from hybrids. It is suggested that serological examination of Fraction I proteins from polyploid species and their known progenitors can indicate the direction of the cross giving rise to the polyploid species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1573-5060
    Keywords: Somatic hybridization ; intergeneric cross ; Nicotiana ; Petunia.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Extensive pollinations were made in attempts to produce selected intergeneric or interspecific hybrids using Nicotiana and Petunia species that exhibit potential for somatic hybridization. Pollination between pairs of species was done by standard and bud-pollination methods. Nicotiana alata or N. tabacum when pollinated reciprocally with selected Petunia species failed to produce hybrids. Likewise, no interspecific hybrids were obtained between Petunia parviflora and 4 Petunia species or P. hybrida. The type of incongruity existing between these species is discussed in relation to the production of hybrids by standard In vitro techniques as compared to somatic hybridization.
    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...