Photoinhibition of photosystem I at chilling temperature and subsequent recovery in Arabidopsis thaliana
Photoinhibition of photosystem I at chilling temperature and subsequent recovery in Arabidopsis thaliana
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DOI：
10.1093/pcp/pch180
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发表时间：
2004-11-01
影响因子：
4.9
通讯作者：
Scheller, HV
中科院分区：
文献类型：
--
作者：
Zhang, SP;Scheller, HV
在暴露于真空冷却（VC）和150 μmol光子 m⁻² s⁻¹的拟南芥中，研究了低温诱导的光抑制及随后的恢复。光系统II（PSII）显示出渐进性损伤，暴露8小时后量子产率降低了14%。相比之下，光系统I（PSI）的损伤在8小时后趋于平稳，体外NADP⁺光还原活性降低了约32%。体内P700测量表明，光抑制处理降低了天线效率。对P700的测量和免疫印迹分析表明，在8小时的光 - 低温处理过程中，受损的PSI没有降解，但在20℃恢复12小时后，类囊体中不再有受损的PSI。因此，受损PSI的降解是恢复过程中的一个步骤，而不是光损伤的直接结果。与光损伤的PSII不同，PSI核心复合物不是被修复，而是完全降解。相比之下，捕光复合物I蛋白的周转缓慢。转移到20℃后，PSII在8小时内完全恢复，而PSI活性恢复非常缓慢，即使在20℃下1周后，基于叶面积的PSI含量仍然较低。结果表明，在拟南芥中，损伤、蛋白质周转和恢复是完全分离的过程。
Chilling-induced photoinhibition and subsequent recovery was studied in Arabidopsis thaliana exposed to VC and 150 mumol photons m(-2) s(-1). PSII showed progressive damage with a 14% decrease in quantum yield after 8 h exposure. In contrast, the damage to PSI leveled off after 8 h with a decrease in in vitro NADP(+) photoreduction activity of around 32%. In vivo P700 measurements demonstrated that antenna efficiency was decreased by the photoinhibitory treatment. Measurements of P700 and immunoblotting demonstrated that the damaged PSI was not degraded during the 8 h light-chilling treatment, but after 12 h recovery at 20degreesC, no damaged PSI remained in the thylakoids. Thus, degradation of damaged PSI is a step in the recovery and not a direct result of photodamage. Unlike photodamaged PSII, the PSI core complex is not repaired but completely degraded. In contrast, light harvesting complex I proteins have a slow turnover. PSII recovered completely within 8 h after transfer to 20degreesC whereas PSI activity recovered very slowly, and the amount of PSI on a leaf area basis remained low even after 1 week at 20degreesC. The results show that damage, protein turnover and recovery are well separated processes in Arabidopsis.