An increase in the “inhibitor-β” content of detached wheat leaves following a period of wilting
Tóm tắt
Wheat seedlings were grown under a 14-hour photoperiod and the first leaves excised at the end of the eighth dark period. The effect of treatments causing wilting on the “inhibitor-β” content of such leaves was studied. When leaves were rapidly wilted (i.e. to a 6% fresh weight loss) and extracted immediately, the amount of “inhibitor-β” per leaf was found to be the same as in fresh turgid leaves. However, when the leaves were maintained in a wilted condition in darkness for a period of 110 minutes, there was a marked increase in “inhibitor-β” content. The greater the degree of wilting (i.e. up to about a 9% loss in fresh weight) the greater the eventual “inhibitor-β” content. Moreover, the increment in “inhibitor-β” was shown to be temperature dependent. The time lapse requirement and the temperature dependency of the “inhibitor-β” formation suggest an enzymic conversion from a precursor. If a similar phenomenon occurs during the wilting of intact plants then the increase in this growth inhibitor might play a role in some of the physiological changes which accompany water stress.
Tài liệu tham khảo
Bayer, M.: Über die Aktivierung des Hemmstoffsystems von Helianthus durch kurzfristige Belichtung. Planta (Berl.) 57, 258–265 (1961).
Bennet-Clark, T. A., and N. P. Kefford: Chromatography of the growth substances in plant extracts. Nature (Lond.) 171, 645–648 (1953).
— M. S. Tambiah, and N. P. Kefford: Estimation of plant growth substances by partition chromatography. Nature (Lond.) 169, 452–453 (1952).
Koshimizu, K., M. Inui, H. Fukui, and T. Mitsui: Isolation of (+)-abscisyl-β-D-glucopyranoside from immature fruit of Lupinus luteus. Agr. Biol. Chem. (Tokyo) 32, 789–791 (1968).
Luckwill, L. C.: Application of paper chromatography to the separation and identification of auxins and growth-inhibitors. Nature (Lond.) 169, 375 (1952).
Masuda, Y.: Effect of light on a growth, inhibitor in wheat roots. Physiol. Plant. 15, 780–790 (1962).
Milborrow, B. V.: The identification of (+)-Abscisin II [(+)-Dormin] in plants and measurements of its concentration. Planta (Berl.) 76, 93–113 (1967).
Pegg, G. F.: An analysis of the effects of Verticillium albo-atrum on the tomato plant. Ph. D. thesis, Univ. of London 1959.
Taylor, H. F.: Carotenoids as possible precursors of abscisic acid in plants. Plant growth regulators. Society of Chemical Industry Monograph, 31, p. 22–35. London 1968.
—, and T. A. Smith: Production of plant growth inhibitors from xanthophylls; a possible source of dormin. Nature (Lond.) 215, 1513–1514 (1967).
Wright, S. T. C.: A chromatographic study of auxins in relation to fruit morphogenesis and fruit drop in blackcurrant (Ribes nigrum). Ph. D. thesis, Univ. of Bristol 1954.
—: Studies on fruit development in relation to plant hormones. III. Auxins in relation to fruit morphogenesis and fruit drop in the blackcurrant (Ribes nigrum). J. Hort. Sci. 31, 196–211 (1956).
Wright, S. T. C.: Multiple and sequential roles of plant growth regulators. VIth Internat. Conference on Plant Growth Substances, Carleton University, Runge Press, p. 521–542 (1968).