Photoinactivation and photoprotection of photosystem II in nature
Photoinactivation and photoprotection of photosystem II in nature
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DOI：
10.1111/j.1399-3054.1997.tb04777.x
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发表时间：
1997-06
影响因子：
6.4
通讯作者：
Jan M. Anderson;Youn-Il Park;W. Chow
中科院分区：
文献类型：
--
作者：
Jan M. Anderson;Youn-Il Park;W. Chow
光系统II不仅在能量传递中起重要作用，而且在监测参与适应环境胁迫的信号转导的分子氧化还原机制中也起重要作用。光系统II（PSII）作为高等植物叶片中光驱动的分子机器，其调控的核心是在10 6 - 10 7个光子传递到叶片后，一个PSII不可避免地发生光失活，尽管光失活行为本身只需要一个光子。PS Ⅱ功能在驯化豌豆叶片显示出的相互作用之间的辐照度和光照时间，表明PS Ⅱ的光失活是一个光剂量效应，取决于吸收的光子数，而不是光子吸收率。因此，PSII光失活将发生在低以及高辐照度。有一个异质性的PSII功能的稳定性，可能与不太稳定的PSII单体位于基粒边缘和更稳定的PSII二聚体贴伏的基粒域。与PSII不可避免的光失活相匹配，绿色植物具有内在的D1蛋白合成能力，以恢复在非常低的光下饱和的PSII功能。PSII在体内的光抑制通常是一种光保护策略而不是一种损伤过程。
Photosystem II plays a central role not only in energy transduction, but also in monitoring the molecular redox mechanisms involved in signal transduction for acclimation to environmental stresses. Central to the regulation of photosystem II (PSII) function as a light-driven molecular machine in higher plant leaves, is an inevitable photoinactivation of one PSII after 10 6 -10 7 photons have been delivered to the leaf, although the act of photoinactivation per se requires only one photon. PSII function in acclimated pea leaves shows a reciprocity between irradiance and the time of illumination, demonstrating that the photoinactivation of PSII is a light dosage effect, depending on the number of photons absorbed rather than the rate of photon absorption. Hence, PSII photoinactivation will occur at low as well as high irradiance. There is a heterogeneity of PSII functional stability, possibly with less stable PSII monomers being located in grana margins and more stable PSII dimers in appressed granal domains. Matching the inevitable photoinactivation of PSII, green plants have an intrinsic capacity for D1 protein synthesis to restore PSII function which is saturated at very low light. Photoinhibition of PSII in vivo is often a photoprotective strategy rather than a damaging process.