Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Life and Medical Sciences  (2)
  • Stem elongation  (2)
  • gibberellins  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Ontogenetic variation in levels of gibberellin A1 in Pisum (1992)
    Springer
    Planta 186 (1992), S. 166-171 
    Details
    ISSN: 1432-2048
    Keywords: Elongation (stem) ; Gibberellin A1 ; Internode length ; Pisum (gibberellins) ; Stem elongation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The levels of the biologically active gibberellin (GA), GA1, and of its precursor, GA20, were monitored at several stages during ontogeny in the apical portions of isogenic tall (Le) and dwarf (le) peas (Pisum sativum L.) using deuterated internal standards and gas chromatography-selected ion monitoring. The levels of both GAs were relatively low on emergence and on impending apical arrest. At these early and late stages of development the internodes were substantially shorter than at intermediate stages, but were capable of large responses to applied GA3. Tall plants generally contained 10–18 times more GA1 and possessed internodes 2–3 times longer than dwarf plants. Further, dwarf plants contained 3–5 times more GA20 than tall plants. No conclusive evidence for the presence of GA3 or GA5 could be obtained, even with the aid of [2H2]GA3 and [2H2]GA5 internal standards. If GA3 and GA5 were present in tall plants, their levels were less than 0.5% and 1.4% of the level of GA1, respectively. Comparison of the effects of gene le on GA1 levels and internode length with the effects of ontogeny on these variables shows that the ontogenetic variation in GA1 content was sufficient to account for much of the observed variation in internode length within the wild-type. However, evidence was also obtained for substantial differences in the potential length of different internodes even when saturating levels of exogenous GA3 were present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00196245
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Gibberellins and phytochrome regulation of stem elongation in pea (1994)
    Springer
    Planta 192 (1994), S. 489-496 
    Details
    ISSN: 1432-2048
    Keywords: Gibberellin (levels, response) ; Light (phytochrome B) ; Mutant (photomorphogenic, gibberellin) ; Pisum (mutants) ; Stem elongation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In garden pea (Pisum sativum L.) neither etiolation nor the phytochrome B (phyB)-response mutation lv substantially alters the level of the major active endogenous gibberellin, GA1 in the apical portion of young seedlings. The phyB-controlled responses to continuous red light and end-of-day far-red light are retained even in a GA-overproducing mutant (sln). Comparison of the effects of the lv mutation and GA1 application on seedling development shows important differences in rate of node development, cell extension and division, and leaf development. These results suggest that in pea the control of stem elongation by light in general and phyB in particular is not mediated by changes in GA1 content. Instead, the increased elongation of dark-grown and lv plants appears to result from increased responsiveness of the plant to its endogenous levels of GA1. Three GA1-deficient mutants, na, ls and le have been used to investigate these changes in responsiveness, and study of these and the double mutants na lv, ls lv and le lv has demonstrated that the relative magnitude of the change in responsiveness is dependent on GA1 level. The difference in pleiotropic effects of GA1 application and the lv mutation suggest that light and GA1 interact late in their respective transduction pathways. A model for the relationship between light, GA1 level and elongation in pea is presented and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203586
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Recent advances in the study of gibberellin mutants (1994)
    Springer
    Plant growth regulation 15 (1994), S. 193-206 
    Details
    ISSN: 1573-5087
    Keywords: elongated ; gibberellins ; mutants ; response ; synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Recent advances in the study of GA mutants are reviewed. Endogenous GAs in the vast majority of GA synthesis and response mutants have now been quantified by physicochemical means, and the implications of the results are discussed. In recent papers the effects of synthesis mutations on processes other than stem elongation have received increased attention, as has the advent of mutants with reportedly elevated GA levels. The ‘feedback theory’ has been formulated, explaining paradoxical observations on endogenous GA levels in certain response mutants. In a significant breakthrough, a GA biosynthesis gene has been cloned, paving the way for a combined approach to future GA research, involving GA mutants, physicochemical analyses, and molecular techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029892
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Identification of gibberellin A4 in Pisum sativum L. and the effects of applied gibberellins A9, A4, A5 and A3 on the le mutant (1995)
    Springer
    Plant growth regulation 16 (1995), S. 257-262 
    Details
    ISSN: 1573-5087
    Keywords: elongation ; gibberellins ; A4, A9, A5 and A3 ; le mutant ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Gibberellin A4 (GA4) was identified for the first time in the garden pea (Pisum sativum) L.), by gas chromatography-mass spectrometry. However, in wild-type shoots the level of GA4 was only about 6% of the level of GA1, and it is therefore unlikely that GA4 plays a major role per se in the control of pea stem elongation. In shoots of the le mutant, GA4 was not detected, while the level of GA9 was approximately twice that found in the wild-type. The le mutation also markedly reduced the elongation response to applied GA9. It appears, therefore, that in Pisum the le mutation blocks the 3β-hydroxylation of GA9 to GA4, in addition to the 3β-hydroxylation of GA20 to GA1. In contrast, the le mutation did not reduce the response to applied GA5, suggesting the step GA5 to GA3 is not catalysed by the enzyme controlled by the Le gene. The step GA5 to GA3 was confirmed in peas by metabolite analysis after treatment with deuterated GA5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00024783
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Viability of human diploid cells as a function of in vitro ageThis investigation was supported in part by U. S. Public Health Service Contract PH43-62-157 from the Viral Carcinogenesis Branch of the National Cancer Institute, and by Public Health Service Research Grant 5-RO1-CA 04534-09 from the National Cancer Institute. (1969)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 74 (1969), S. 219-221 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The fraction of cell capable of division was determined for (1) population of the human diploid cell strains, WI38 after different numbers of subcultivations in vitro and (2) a single population of WI38 cells at intervals throughout its entire in vitro lifespan. In both cases the percentage of cells capable of division decreased with increasing age in tissue culture. The rate and the magnitude of the decrease is sufficient to account for the limited in vitro lifespan reported by other investigators. Furthermore, the decrease in the fraction of cells capable of division in similar in some respects of senescence among human populations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040740302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Clone size variation in the human diploid cell strain, wi-38Supported in part by U.S.P.H.S. Research contract PH43-62-157 from the Viral Carcinogenesis Branch, National Cancer Institute, and grant 5-R01-CA04534 from the National Cancer Institute. (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 82 (1973), S. 75-80 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: By mapping the location of isolated single cells; and then counting the number of cells at each location as a function of time. it was possible to accumulate data on the growth history for each of a large group of clones. The clone size distribution, its mean and standard deviation were computed for each day in culture. Variations in schedule of medium change and time of exposure to trypsin, did not measurably affect variation in clone size. Neither could clone size variation be accounted for on the basis of (1) occurrence of nondividing cells nor (2) presence of heritable growth rate variants in the population. It is probable that clone size variation under our conditions is primarily a consequence of a highly variable interdivision time among the constituent cells.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040820109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...