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小麦叶片的状态转换涉及PSII向PSI激发能满溢的变化

谭新星, 许大全, 沈允钢

中科院上海植物生理研究所. 上海 200032

摘要

小麦叶片照远红光后, 其叶绿素荧光参数Fm/Fo和两个光系统低温荧光产量比值F685/F735升高, 照红光后, 其Fm/Fo和F685/F735降低; 在照远红光或红光过程中, 与F685/F735的变化相比, Fm/Fo的变化幅度在较短的时间内达到最大; NaF预处理的叶片经远红光照射时, 其Fm/Fo和F685/F735不增加; DCMU预处理的叶片经红光照射时,其Fm/Fo和F685/F735降低的幅度比对照小。结果表明,小麦叶片状态转换过程中两个光系统间能量分配的变化至少部分地与激发能满溢变化有关。这种满溢的变化与捕光色素蛋白复合体LHCⅡ的磷酸化相联, 并且, 与光吸收截面变化相比,满溢的变化是对两个光系统不平衡光吸收的较快响应。

关键词： 状态转换; PSⅡ光化学效率; 满溢; MICⅡ磷酸化; 叶绿素荧光; 小麦

The involvement of change in excitation energy spillover from PSII to PSI during state transitions in wheat leaves

Tan Xinxing, Xu Daquan, Shen Yungang

Shanghai Institute of Plant Physiology, The Chinese Academy of Sciences. Shanghai 200032

Abstract

The red light or far red light induced changes in chlorophyll fluorescence parameters and fluorescence spectrum at low temperature were observed in wheat leaves to investigate whether the change in excitation energy distribution between the two photosystems during state transitions involves the change in excitation energy spillover from PSII to PSI.The chlorophyll fluorescence parameter, Fm/Fo, and the ratio of fluorescence yield of the two photosystems at low temperature, F685/F735,increased when leaves were exposured to lightI (far red light), while they decreased when leaves were exposured to lightII (red light). During illumination by lightI or lightII, the change in Fm/Fo attained to a maximum extent in a shorter time as compared with the change in F685/F735. In the leaves fed with NaF through its cut end, Fm/Fo and F685/F735 did not increase on exposure to lightI. The extent of decrease of Fm/Fo and F685/F735 in the leaves fed with DCMU also through the cut end of leaf was less than that in control without feeding of DCMU on exposure to lightII. Based on the results above, the following conclusions are made: a)the change in excitation energy distribution between the two photosystems during state transitions is, at least partly, related to change in excitation energy spillover from PSII to PSI; b) the change in the spillover is associated with phosphorylation of LHC II, and it is a quicker response to the inbalant light absorption of the two photosystems as compared with the change in light absorption cross-section.

Key words: State transition;Photochemical efficiency of PSⅡ;Spillover;LHCⅡphosphorylation;Chlorophyll fluorescence;Wheat

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引用本文：

谭新星, 许大全, 沈允钢. 小麦叶片的状态转换涉及PSII向PSI激发能满溢的变化[J]. 生理学报 1997; 49 (1): .

Tan Xinxing, Xu Daquan, Shen Yungang. The involvement of change in excitation energy spillover from PSII to PSI during state transitions in wheat leaves. Acta Physiol Sin 1997; 49 (1): (in Chinese with English abstract).