Expression of flavodiiron protein rescues defects in electron transport around PSI resulting from overproduction of Rubisco activase in rice
Expression of flavodiiron protein rescues defects in electron transport around PSI resulting from overproduction of Rubisco activase in rice
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DOI：
10.1093/jxb/erac035
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发表时间：
2022-02-02
影响因子：
6.9
通讯作者：
Makino, Amane
中科院分区：
文献类型：
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作者：
Suganami, Mao;Konno, So;Makino, Amane
在过量产生Rubisco活化酶（RCA）的转基因水稻中观察到光系统I的脆弱性。在这项研究中，我们研究了RCA过度生产的影响PSI光抑制的敏感性在三个线的植物过度表达RCA（RCA-ox）。在所有RCA-ox植物中，PSI [Y（I）]的量子产率降低，而相反PSI [Y（NA）]的受体侧限制的量子产率增加，特别是在低光条件下。在RCA含量最高的转基因株系（RCA-ox 1）中，PSII [Y（II）]的量子效率和CO2同化在弱光下也有所下降。当叶片暴露于强光（2000 μ mol photon m（-2）s（-1））60 min时，RCA-ox 1中PSI（P-m）的最大活性急剧下降。这些结果表明，过量的RCA干扰PSI电子传递控制，从而增加PSI对光抑制的敏感性。当flavodiiron蛋白（FLV），作为一个大的电子汇下游的PSI，在RCA-ox 1背景（RCA-FLV），PSI和PSII参数，和CO2同化的表达恢复到野生型水平。因此，FLV的表达恢复了RCA-ox植物中PSI的鲁棒性。Rubisco活化酶的过量产生干扰PSI周围的电子传递并增加其对光抑制的敏感性，但这些缺陷被水稻植物中的flavodiiron蛋白的表达所拯救。
Fragility of photosystem I has been observed in transgenic rice plants that overproduce Rubisco activase (RCA). In this study, we examined the effects of RCA overproduction on the sensitivity of PSI to photoinhibition in three lines of plants overexpressing RCA (RCA-ox). In all the RCA-ox plants the quantum yield of PSI [Y(I)] decreased whilst in contrast the quantum yield of acceptor-side limitation of PSI [Y(NA)] increased, especially under low light conditions. In the transgenic line with the highest RCA content (RCA-ox 1), the quantum yield of PSII [Y(II)] and CO2 assimilation also decreased under low light. When leaves were exposed to high light (2000 mu mol photon m(-2) s(-1)) for 60 min, the maximal activity of PSI (P-m) drastically decreased in RCA-ox 1. These results suggested that overproduction of RCA disturbs PSI electron transport control, thus increasing the susceptibility of PSI to photoinhibition. When flavodiiron protein (FLV), which functions as a large electron sink downstream of PSI, was expressed in the RCA-ox 1 background (RCA-FLV), PSI and PSII parameters, and CO2 assimilation were recovered to wild-type levels. Thus, expression of FLV restored the robustness of PSI in RCA-ox plants.Overproduction of Rubisco activase disturbs electron transport around PSI and increases its susceptibility to photoinhibition, but these defects are rescued by expression of the flavodiiron protein in rice plants.