A physiological role of cyclic electron transport around photosystem I in sustaining photosynthesis under fluctuating light in rice.
A physiological role of cyclic electron transport around photosystem I in sustaining photosynthesis under fluctuating light in rice.
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DOI：
10.1038/srep20147
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发表时间：
2016-02-02
影响因子：
4.6
通讯作者：
Shikanai T
中科院分区：
文献类型：
--
作者：
Yamori W;Makino A;Shikanai T
植物在一天中经历高度变化的光照环境。为了揭示其对波动光的光合响应的分子机制，我们研究了光系统 I (CEF-PSI) 周围的两个循环电子流（一个依赖于质子梯度调节 5 (PGR5)，一个依赖于 NADH 脱氢酶样复合物 (NDH)）在水稻 (Oryza sativa L.) 波动光下光合调节中的作用。 PGR5依赖性CEF-PSI的损伤会在突然照射后立即抑制光合反应，而NDH依赖性CEF-PSI的损伤则不会。然而，PGR5依赖性或NDH依赖性CEF-PS1的损伤降低了波动光下的光合速率，导致PSI的光抑制并因此导致植物生物量减少。结果强调：（1）PGR5依赖的CEF-PSI是持续高光后波动光条件下对高光强度快速光合反应的关键调节因子； (2)PGR5依赖性和NDH依赖性CEF-PSI在重复光波动下维持水稻光合作用和植物生长方面都具有生理作用。由 CEF-PSI 管理的高度响应的调节系统似乎能够在自然波动的光照条件下优化光合作用和植物生长。
Plants experience a highly variable light environment over the course of the day. To reveal the molecular mechanisms of their photosynthetic response to fluctuating light, we examined the role of two cyclic electron flows around photosystem I (CEF-PSI)—one depending on PROTON GRADIENT REGULATION 5 (PGR5) and one on NADH dehydrogenase-like complex (NDH)—in photosynthetic regulation under fluctuating light in rice (Oryza sativa L.). The impairment of PGR5-dependent CEF-PSI suppressed the photosynthetic response immediately after sudden irradiation, whereas the impairment of NDH-dependent CEF-PSI did not. However, the impairment of either PGR5-dependent or NDH-dependent CEF-PSl reduced the photosynthetic rate under fluctuating light, leading to photoinhibition at PSI and consequently a reduction in plant biomass. The results highlight that (1) PGR5-dependent CEF-PSI is a key regulator of rapid photosynthetic responses to high light intensity under fluctuating light conditions after constant high light; and (2) both PGR5-dependent and NDH-dependent CEF-PSI have physiological roles in sustaining photosynthesis and plant growth in rice under repeated light fluctuations. The highly responsive regulatory system managed by CEF-PSI appears able to optimize photosynthesis and plant growth under naturally fluctuating light conditions.