叶绿体PSⅡ光能耗散机制的研究进展  

The Progress on the Mechanisms of Dissipating Excess Light Energy in Chloroplast PS Ⅱ

作　　者：李晓萍[1] 陈贻竹[1] 郭俊彦[1] 

机构地区：[1]中国科学院华南植物研究所

出　　处：《生物化学与生物物理进展》1996年第2期145-149,共5页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金

摘　　要：植物的光合作用包括光能固定和过剩光能的耗散两个方面，在光能耗散方面，除了人们以前所认识的光呼吸、Ｍｅｈｌｅｒ反应等生化机制外，近几年人们发现在光合系统Ⅱ（ＰＳⅡ）复合体内还存在三种光能耗散方式：ａ．围绕ＰＳⅡ的电子循环；ｂ．与类囊体膜的能量化和叶黄素循环有关的热耗散；ｃ与ＰＳⅡ反应中心异质化及Ｄ１蛋白修复循环有关的能量耗散机制．Photosynthetic process should include both the process of light energy utilization and the process of light energy dissipation. In the latter process, besides the biochemical mechanisms of photorespiration and Mehler reaction,there are also some biophysical processes. These processes can be summarized into follwing three aspects: (1) Energy dissipation through electric cycle around PS Ⅱ. This cycle includes PS Ⅱreaction center, plastoquinone, and cytochrome b-559. This mechanism can recombine with the charge separated PS Ⅱ center, so that prevent the oxidation of chlorophyll induced by the longer existence of oxidative P680+. (2) Heat dissipation correlated with the thylakoid membrane energization and xanthophyll cycle. This mechanism exists in LHC Ⅱ, and responses quickly at relatively lower excess light stress.(3) Heat dissipation via photosystem Ⅱ heterogeneity and the turnover of D1 protein. This mechanism bases on the hypothesis that there are two kinds of photosystem Ⅱ. One is photosynthetic active with higher linear electron transport and higher fluorescence emission but lower heat dissipation. The other is photosynthetic inactive with lower linear electron transport, lower fluorescence emission and higher heat dissipation.The latter is called dissipative PS Ⅱ. This dissipative PS Ⅱ can be reactive directly without protein synthesis or indirectly through D1 protein turnover process.

关 键 词：叶绿体 光合系统 光能耗散 PSII 

分 类 号：Q732[生物学—分子生物学]