Rubber Research Institute, Chinese Academy of Tropical Agricultural Science, Danzhou, Hainan, China.
School of Life Science and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong.
Plant Cell Environ. 2019 Apr;42(4):1302-1317. doi: 10.1111/pce.13482. Epub 2019 Jan 11.
Light is essential for the plant establishment. Arabidopsis seedlings germinated in the dark cannot grow leaf and only have closed cotyledons. However, exogenous application of H O can induce leaves (establishment) in the dark. Comparative transcriptomic analysis revealed that light-responsive genes were activated by H O treatment. These genes are functionally correlated with photosynthesis, photorespiration, and components of photosystem, such as antenna proteins and light-harvesting chlorophyll proteins. We further found that application of H O facilitates cell cycle by accelerating G -M checkpoint transition in shoot apical meristem. Phytochrome-mediated light signalling pathway was also involved in the H O -facilitated establishment process. The constitutive photomorphogenesis 1 and phytochrome interacting factor 3 proteins were shown to be down-regulated by H O treatment and accordingly removed their inhibitory effects on photomorphogenesis in the dark. The crosstalk between oxidation and light signal pathways explains the mechanism that H O regulates plant dark establishment. The endogenous photorespiratory H O production was mimicked by overexpression of glycolate oxidase genes and supplement of substrate glycolate. As expected, seedling establishment was also induced by the endogenously produced H O under dark condition. These findings also suggest that photorespiratory H O production is at least partially involved in postgermination establishment.
光是植物发育所必需的。在黑暗中萌发的拟南芥幼苗无法生长叶片，只有闭合的子叶。然而，外源施加 H O 可以诱导黑暗中的叶片（发育）。比较转录组分析显示，H O 处理激活了光响应基因。这些基因与光合作用、光呼吸以及光系统的组成部分（如天线蛋白和光捕获叶绿素蛋白）功能相关。我们进一步发现，H O 通过加速茎尖分生组织中 G 1 -M 检验点的转变来促进细胞周期。光敏色素介导的光信号通路也参与了 H O 促进发育的过程。组成型光形态建成 1 和光敏色素相互作用因子 3 蛋白被 H O 处理下调，因此它们对黑暗中光形态建成的抑制作用被解除。氧化和光信号通路之间的串扰解释了 H O 调节植物暗发育的机制。过表达乙醛酸氧化酶基因和补充底物乙醛酸可以模拟内源性光呼吸 H O 的产生。不出所料，黑暗条件下内源性产生的 H O 也能诱导幼苗发育。这些发现还表明，光呼吸 H O 的产生至少部分参与了萌发后的发育。
