GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 20 (1967), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A comparative study of tryptophan conversion in different regions of the sunflower seedling indicates that the regions most active in converting tryptophan on a pathway to auxin are the root apical segments and young leaves; next highest in activity is the cotyledonary tissue. The stem apex proper with leaf primordia is less active than the above regions in converting the auxin precursor. Hypocotyl tissue was observed to be least active. Pre-treatment of the apical bud region of the stem with gibberellic acid (GA) gives rise to tryptophan conversion rates which are 2.1 times those in untreated seedlings. The enhanced tryptophan conversion in the apical bud is followed by an increased elongation rate of the 1st internode which is 2.2 times that in the 1st internode of untreated seedlings. Treatment of the seedlings with Cycocel [(2-chloroethyl)trimethylamnionium chloride] does not reduce tryptophan conversion in the apical bud region of the seedling although elongation of the stem is greatly retarded.Indoleacetic acid (IAA) destruction in cell free preparations as well as in whole sections of the elongating region of the seedling stem was studied. IAA-1-14C destruction rates with the release of 14CO2 in whole sections of 1st internode tissue were approximately 3 times those in cell free preparations of the same region. No significant changes in IAA destruction rates in seedlings pre-treated with GA or Cycocel were observed.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 227 (1970), S. 372-373 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] It seems reasonable that the new form of water will have some general features in common with ice and the normal liquid, and so we may expect it to be an electrically neutral association of water molecules weakly bound together. Spectroscopic and theoretical results4 show that hydrogen bonding in ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 196 (1962), S. 663-664 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Examples of spectra for which the method is applicable include high-resolution electron spin resonance, spin-spin coupling in nuclear magnetic resonance, and X-ray crystallography. In the third case the Patterson map can be treated as a centro-symmetric three-dimensional spectrum and the methods we ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 20 (1967), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Chloramphenicol, actinomycin D, and other inhibitors of protein synthesis promote abscission in several plant genera. Abscission is accelerated in species where an abscission layer is present, as well as in tissue where no abscission layer develops prior to abscission. The inhibitors promote abscission in species where cell division is reported to precede the separation processes as well as in tissues where no cell division is associated with the initiation of abscission. Indoleacetic acid (IAA) or auxin precursors, when applied with chloramphenicol and aclinomycin D, overcome the promotive effects of the inhibitors on abscission. These inhibitors apparently do not promote abscission through their effects on auxin precursor conversion, IAA transport, and IAA destruction in the petiole. IAA increases the incorporation of leucine-1-14C into a trichloroacetic acid precipitable fraction of the abscission zone under conditions where abscission is retarded. A low concentration of IAA which accelerates abscission, decreases incorporation of leucine into protein. Other promoters of abscission — chloramphenicol, d-aspartic acid, and gibberellic acid —also decrease the incorporation of leucine into the protein of the abscission zone. The data indicate that enzymes required for the degradative processes associated with abscission are already present in the abscission zone whereas a continuous synthesis of protein is required for the retention of the leaf.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 20 (1967), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Application of gibberellic acid (GA) to the apical region of the stem enhances 14CO2 release from tryptophan-l-14C in cell free preparations of the apical region. Although GA when applied to the apical region markedly accelerates abscission rates of debladed petioles at the 4th node, the enhancement effect on tryptophan metabolism appears to be restricted to the apical bud region. The increased levels of diffusible auxin in Coleus stems, observed earlier by Muir and Valdovinos (1965), appear to be due to the GA effect on auxin precursor conversion rather than to an altered rate of auxin destruction. GA pre-treatment does not significantly alter destruction rates of auxin in the stem tissue. This is demonstrated by the release of 14CO2 from IAA-1-14C by sections of internode tissue.While a multiple deblading pattern retards abscission of debladed petioles considerably, application of GA to debladed petioles at the basal region of the stem restores the normal rates of abscission at debladed distal nodes. No significant change in the abscission rates at treated nodes is observed. The GA effect on abscission at distal nodes is attributed to the effect of the growth substance on auxin precursor conversion in the apical region. In these experiments, as in the case of plants treated in the apical region with GA, auxin destruction rates in the stem are not altered significantly.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 197 (1963), S. 897-897 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] It is also important to understand XeF4 in terms of approximate solutions to Schrodinger's equation, and an explanation based primarily on our knowledge of the electronic structure of isolated atoms and ions has been given3. The xenon nuoride bond is attributed to the atomic distortion4 produced by ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 233 (1971), S. 550-551 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The original structure model which provided a scheme for rationalizing the many diverse properties of polywater consisted of stacked layers built from hexagonal units, composed of symmetrical hydrogen bonds as proposed on qualitative grounds by Lippincott et al.2. The resulting three-dimensional ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...