Summary
In extracts of Coleus rehneltianus shoots abscisic acid was identified by thin layer chromatography and by spectropolarimetry.
Diffusates from the petiole of isolated leaves were tested in an abscission test. According to previous results (Part I) these experiments allow conclusions concerning the hormonal flux from the lamina.
The next step was to separate the diffusates by paper chromatography. The relative amounts of IAA and ABA were estimated on the basis of a biological assay. Young leaves yield ten times as much IAA to an agar receptor as green adult leaves and twenty times as much as yellow senescent leaves. On the other hand young leaves do not transmit detectable amounts of ABA to the receptor. Diffusates from adult leaves contain only a small amount of ABA, whereas those of senescent leaves contain a considerable amount.
Evidently the induction of leaf abscission is not effected by a strong decrease of the IAA content during the development of a young leaf into an adult leaf. One is lead to assume that the rapid increase of the ABA flux during senescence is responsible for the induction of the abscission process.
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Literatur
Addicott, F. T., Lynch, R. S., Carns, H. R.: Auxin gradient theory of abscision regulation. Science 121, 644–645 (1955).
Jacobs, W. P., Shield, J. A. Jr., Osborne, D. J.: Senescence factor and abscision of Coleus leaves. Plant Physiol. 37, 104–106 (1962).
Milborrow, B.V.: The identification of (+)-abscisin II ((+)-dormin) in plants and measurements of its concentrations Plata (Berl.) 76, 93–113 (1967).
—: The metabolism of abscisic acid. J. exp. Botany, 21, 17–29 (1970).
Osborne, D. J.: Acceleration of abscission by a factor produced in senescent leaves. Nature (Lond.) 176, 1161–1163 (1955).
Scott, T. K., Jacobs, W. P.: Critical assessment of techniques for identifying the physiologically significant auxins in plants. Régulateurs Naturels de la Croissance Végétale, S. 457–474, Hrsg. J. P. Nitsch. Paris: CNRS 1964.
Vendrig, J. C.: On the abscission of debladed petioles in Coleus rhenaltianus especially in relation to the effect of gravity. Wentia 3, 1–96 (1960).
Wetmore, R. H., Jacobs, W. P.: Studies on abscission: the inhibiting effect of auxin. Amer. J. Botany 40, 272–276 (1953).
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Zweiter Teil einer Dissertation des Fachbereiches Biologie der Universität Hamburg
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Böttger, M. Die hormonale Regulation des Blattfalls bei Coleus rehneltianus Berger. Planta 93, 205–213 (1970). https://doi.org/10.1007/BF00387641
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DOI: https://doi.org/10.1007/BF00387641