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Drozdova I. S. Pustovoitova T. N. Dzhibladze T. G. Barabanshchikova N. S. Zhdanova N. E. Maevskaya S. N. Bukhov N. G. 《Russian Journal of Plant Physiology》2004,51(5):668-675
Photosynthetic activities and the redox states of photosystem I (PSI) and photosystem II (PSII) in intact leaves of cucumber plants (Cucumis sativus L.), as well as the sucrose and starch contents were examined under conditions of ongoing soil water deficit imposed by the cessation of watering. As the soil drought progressed, the maximum rate of photosynthetic CO2 fixation was shown to decrease. These changes in the maximum photosynthetic rate occurred synchronously with changes in the maximum quantum yield of photosynthesis. Under soil water deficit, the reduced form of PSII primary acceptor Q
A was accumulated only at photon flux densities of about 100 mol/(m2 s). At such photon flux densities, the changes in nonphotochemical quenching (qN) induced by soil water deficit were opposite to changes in photochemical quenching parameter (1 – qP). Irrespective of the duration of soil drought, the relationship between steady-state concentrations of photochemically inactive reaction centers of PSI and PSII (the fractions of P700 and Q
A in the oxidized and reduced state, respectively) was almost linear, which provides evidence for the concerted operation of both photosystems. The conditions of soil water deficit promoted sucrose accumulation in the source leaf, which was paralleled by a substantial decrease in the amount of starch in the same leaf. The highest content of sucrose in the leaf after a 7-day drought was correlated with the largest decrease in photosynthetic activity. It is concluded that the progressive drought triggers an endogenous mechanism that regulates photosynthesis through feedback relations, namely, the inhibition of photosynthesis by its end products. 相似文献
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Leaf Growth,Photosynthetic Rate,and Phytohormone Contents in Cucumis sativus Plants under Progressive Soil Drought 总被引:1,自引:0,他引:1
Pustovoitova T. N. Drozdova I. S. Zhdanova N. E. Zholkevich V. N. 《Russian Journal of Plant Physiology》2003,50(4):441-443
Effects of progressive soil drought on leaf growth, the rate of photosynthesis, and phytohormone contents were followed in the experiments with cucumber (Cucumis sativus L.) plants. Suppression of photosynthesis by drought did not immediately cause growth retardation, because the latter was observed one day earlier than the inhibition of photosynthesis. In the meantime, growth retardation could be caused by a decline in IAA and cytokinin contents, rather than ABA accumulation, because ABA accumulated when the growth has been already suppressed. 相似文献
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Tamara Pustovoitova 《Biologia Plantarum》1987,29(5):338-341
Effect of abscisic acid on cell permeability in leaves ofIresine u allisi hort. and roots ofBeta vulgaris L. were examined. An increase of betacyanin leakage from leaf cells was shown by ABA at 10−4, 10−7 or 10−9 M concentrations in water solution at 25 °C. The efflux of batacyanin from tissues did not change during the joint action
of ABA and PEG 1000. ABA could lower the betacyanin leakage fromIresine leaves and beet-root slices under severe osmotic stress, as was found by deplasmolysis. The results suggest that ABA elicits
some alteration in density of tonoplast membranes under dehydration.
Presented at the International Symposium “Plant Growth Regulators” held on June 18–22, 1984 at Liblice, Czechoslovakia. 相似文献
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Changes in the Levels of IAA and ABA in Cucumber Leaves under Progressive Soil Drought 总被引:1,自引:0,他引:1
Pustovoitova T. N. Zhdanova N. E. Zholkevich V. N. 《Russian Journal of Plant Physiology》2004,51(4):513-517
Changes in the IAA and ABA contents in cucumber (Cucumis sativus L.) leaves during adaptation to drought were studied. An increase in the water-retaining capacity and heat resistance of leaves indicating the onset of adaptation occurred when the leaf growth has been already suppressed. There was a transient increase in the ABA content during the initial stage of adaptation. An increased IAA content was maintained for a longer period, throughout about two-third of the adaptation period. A second increase in the ABA content was observed before the onset of leaf permanent wilting, when IAA content already decreased. Our data suggest that not only ABA, but also IAA are involved in the development of defense responses during the adaptation to drought. 相似文献
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Effect of Phytohormone Biosynthesis Genes (ipt and iaaM + iaaH) on the Sexual Reproduction of Transgenic Tobacco Plants 总被引:1,自引:0,他引:1
Bavrina T. V. Milyaeva E. L. Machácčková I. Pustovoitova T. N. Gurko N. A. Kasumova I. V. Zhdanova N. E. 《Russian Journal of Plant Physiology》2002,49(4):484-491
Transformation of Nicotiana silvestris Spegar et Comes plants by the ipt or iaaM + iaaH genes changed the hormonal status of plant reproductive organs. The total content of cytokinins and ABA increased, whereas IAA content in the pistils and anthers of the ipt-plants did not change. Reduced fertility of the ipt plants correlated with an elevated cytokinin and ABA contents of their reproductive organs. Pollen tubes of these plants showed defective growth in pistils in situ, and ovaries manifested a low metabolic activity. The transgenic (iaaM + iaaH)-plants were characterized by an elevated IAA content and reduced ABA content, whereas the total content of cytokinins did not change. The fertility of these plants did not differ from that in the wild type. 相似文献
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