PGR5 is involved in cyclic electron flow around photosystem I and is essential for photoprotection in Arabidopsis
PGR5 is involved in cyclic electron flow around photosystem I and is essential for photoprotection in Arabidopsis
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DOI：
10.1016/s0092-8674(02)00867-x
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发表时间：
2002-08-09
期刊：
影响因子：
64.5
通讯作者：
Shikanai, T
中科院分区：
文献类型：
--
作者：
Munekage, Y;Hojo, M;Shikanai, T
在光合作用过程中，植物必须控制光能的利用，以避免光抑制。我们分离出一个拟南芥突变体，pgr5（质子梯度调节），其中下调光系统11的光化学反应，强光受损。PGR 5编码一种新的类囊体膜蛋白，其参与电子从铁氧还蛋白到质体醌的转移。这种替代的电子传递途径，其分子身份长期以来一直不清楚，已知在体内在光系统1周围的循环电子流中起作用。我们提出，PGR 5途径有助于产生一个DeltapH，诱导热耗散时，卡尔文循环活动减少。在这些条件下，PGR 5途径还起到限制光系统1受体侧的过度还原的作用，从而防止光系统I光抑制。
During photosynthesis, plants must control the utilization of light energy in order to avoid photoinhibition. We isolated an Arabidopsis mutant, pgr5 (proton gradient regulation), in which downregulation of photosystem 11 photochemistry in response to intense light was impaired. PGR5 encodes a novel thylakoid membrane protein that is involved in the transfer of electrons from ferredoxin to plastoquinone. This alternative electron transfer pathway, whose molecular identity has long been unclear, is known to function in vivo in cyclic electron flow around photosystern 1. We propose that the PGR5 pathway contributes to the generation of a DeltapH that induces thermal dissipation when Calvin cycle activity is reduced. Under these conditions, the PGR5 pathway also functions to limit the overreduction of the acceptor side of photosystem 1, thus preventing photosystern I photoinhibition.