Institute of Basic Biological Problems RAS, 142290 Pushchino, Moscow Region, Russia
Institute of Basic Biological Problems RAS, 142290 Pushchino, Moscow Region, Russia.
J Exp Bot. 2015 Dec;66(22):7151-64. doi: 10.1093/jxb/erv410. Epub 2015 Aug 31.
Higher plants possess the ability to trigger a long-term acclimatory response to different environmental light conditions through the regulation of the light-harvesting antenna size of photosystem II. The present study provides an insight into the molecular nature of the signal which initiates the high light-mediated response of a reduction in antenna size. Using barley (Hordeum vulgare) plants, it is shown (i) that the light-harvesting antenna size is not reduced in high light with a low hydrogen peroxide content in the leaves; and (ii) that a decrease in the antenna size is observed in low light in the presence of an elevated concentration of hydrogen peroxide in the leaves. In particular, it has been demonstrated that the ability to reduce the antenna size of photosystem II in high light is restricted to photosynthetic apparatus with a reduced level of the plastoquinone pool and with a low hydrogen peroxide content. Conversely, the reduction of antenna size in low light is induced in photosynthetic apparatus possessing elevated hydrogen peroxide even when the reduction level of the plastoquinone pool is low. Hydrogen peroxide affects the relative abundance of the antenna proteins that modulate the antenna size of photosystem II through a down-regulation of the corresponding lhcb mRNA levels. This work shows that hydrogen peroxide contributes to triggering the photosynthetic apparatus response for the reduction of the antenna size of photosystem II by being the molecular signal for the long-term acclimation of plants to high light.
高等植物具有通过调节光系统 II 光捕获天线大小来触发对不同环境光条件的长期适应反应的能力。本研究深入了解了引发天线大小减小的高光介导反应的信号的分子性质。使用大麦（Hordeum vulgare）植物，表明（i）在叶子中过氧化氢含量低的高光下，光捕获天线大小不会减小；（ii）在叶子中过氧化氢浓度升高的情况下，在低光下观察到天线大小减小。特别是，已经证明在高光下减少光系统 II 天线大小的能力仅限于具有降低的质体醌池水平和低过氧化氢含量的光合机构。相反，即使质体醌池的还原水平低，在具有高过氧化氢的光合机构中也会诱导低光下天线大小的减少。过氧化氢通过下调相应的 lhcb mRNA 水平来影响调节光系统 II 天线大小的天线蛋白的相对丰度。这项工作表明，过氧化氢通过作为植物对高光长期适应的分子信号，有助于触发光合机构减少光系统 II 天线大小的反应。
