The different roles of chilling temperatures in the photoinhibition of photosystem I and photosystem II

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作   者：

Kintake Sonoike; 

作者机构：

Tokyo 113-0033;  Department of Biological Sciences;  Hongo;  University of Tokyo;  Graduate School of Science;  Bunkyo-ku;  Japan; 

关键词：

photosystems I and II;  chilling damage;  photosynthesis;  cyclic electron transfer;  photoinhibition;  excitation pressure; 

期刊名称：

Journal of Photochemistry and Photobiology, B. Biology: Official Journal of the European Society for Photobiology

i s s n：

1011-1344

年卷期：

1999 年 48 卷 2/3 期

页   码：

136-141

页   码：

摘   要：

The role of chilling temperatures on photoinhibition of photosystems I and II (PSI and PSII) under weak light has been examined in cucumber, a chilling-sensitive plant. The extent of PSII photoinhibition, determined by pulse-modulated fluorescence in vivo, is closely related to the redox state of the PSII electron acceptor Q_A, measured as a fluorescence parameter, 1-q_p. On the other hand, the extent of PSI photoinhibition, which is only observed in chilling-sensitive plants at chilling temperatures, cannot be related to the redox state of Q_A, suggesting that the underlying mechanism is different from that of PSII photoinhibition. Chilling treatment at low photon flux densities is found to enhance cyclic electron flow around PSI. Both PSI photoinhibition and enhanced cyclic electron flow show similar temperature dependence, with the threshold temperature at 10deg C.