Glutathione reductase 2 maintains the function of photosystem II in Arabidopsis under excess light
Glutathione reductase 2 maintains the function of photosystem II in Arabidopsis under excess light
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DOI：
10.1016/j.bbabio.2016.02.011
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发表时间：
2016-06-01
影响因子：
4.3
通讯作者：
Lu, Congming
中科院分区：
文献类型：
--
作者：
Ding, Shunhua;Jiang, Rui;Lu, Congming
谷胱甘肽还原酶在通过抗坏血酸-谷胱甘肽循环清除过氧化氢分子中起着至关重要的作用。在这项研究中，我们使用了谷胱甘肽还原酶2(GR2)水平降低的转基因拟南芥植物来研究这种GR2活性是否保护了过量光照下的光合作用机制。转基因植株对过量光照和积累高水平的H_2O_2高度敏感。光系统II(PSII)活性在转基因植株中显著降低。闪光诱导的荧光驰豫和热释光检测表明，在转基因植物中，Q(A)和Q(B)之间的电子传递受到抑制，Q(B)的氧化还原电位降低。免疫印迹和蓝色天然凝胶分析表明，转基因植株中PSII蛋白和PSII复合体的表达水平降低。光损伤PSII的修复和类囊体膜蛋白的体内脉冲标记分析表明，在转基因植物中，光损伤的PSII的修复受到抑制，这是由于抑制了D1蛋白的从头合成。综上所述，我们的结果表明，在强光条件下，GR2在维持PSII受体侧的功能和通过防止H_2O_2积累来修复光损伤的PSII方面发挥着重要作用。此外，我们的结果提供了过氧化氢在植物体内积累在光抑制中的作用的详细信息。(C)2016爱思唯尔B.V.保留所有权利。
Glutathione reductase plays a crucial role in the elimination of H2O2 molecules via the ascorbate-glutathione cycle. In this study, we used transgenic Arabidopsis plants with decreased glutathione reductase 2 (GR2) levels to investigate whether this GR2 activity protects the photosynthetic machinery under excess light. The transgenic plants were highly sensitive to excess light and accumulated high levels of H2O2. Photosystem II (PSII) activity was significantly decreased in transgenic plants. Flash-induced fluorescence relaxation and thermoluminescence measurements demonstrated inhibition of electron transfer between Q(A) and Q(B) and decreased redox potential of Q(B) in transgenic plants. Immunoblot and blue native gel analysis showed that the levels of PSII proteins and PSII complexes were decreased in transgenic plants. Analyses of the repair of photodamaged PSII and in vivo pulse labeling of thylakoid proteins showed that the repair of photodamaged PSII is inhibited due to the inhibition of the synthesis of the D1 protein de novo in transgenic plants. Taken together, our results suggest that under excess light conditions, GR2 plays an important role in maintaining both the function of the acceptor side of PSII and the repair of photodamaged PSII by preventing the accumulation of H2O2. In addition, our results provide details of the role of H2O2 in vivo accumulation in photoinhibition in plants. (C) 2016 Elsevier B.V. All rights reserved.