The Mechanism of Nonphotochemical Quenching: The End of the Ongoing Debate.
The Mechanism of Nonphotochemical Quenching: The End of the Ongoing Debate.
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非光化学猝灭机制：持续争论的结束。
DOI：
10.1104/pp.19.00538
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发表时间：
2019
期刊：
影响因子：
7.4
通讯作者：
Ruban AV
中科院分区：
文献类型：
--
作者：
Ruban AV
亲爱的编辑，光合作用是我们所知的生物圈所创造的，它允许包括我们自己在内的异养生物蓬勃发展，并支持了数百万年。然而，微妙的含氧光合机制容易受到损害，由于偶尔，定期或持续暴露于强光。过量的光会导致捕光天线吸收太多的光子，并过度激发其色素，这会损害光合膜，特别是释放氧气的PSII的组分。这抑制了植物的生长和生产力。称为非光化学猝灭（NPQ）的光保护的生理机制是在类囊体膜中进行的主要和最快的反应，以无害地耗散过量的光能（Demmig-Adams等人，2014年）。关于NPQ中涉及的蛋白质、色素和动态过程存在两种相反的观点（Ruban等人，2012年）。最近对LHCII小天线突变体的研究揭示了真相，一种观点认为存在特定的光保护色素-蛋白质复合物，它在熄灭捕光天线中多余的光子方面至关重要。这些由CP 24、CP 26和CP 29组成的次要触角复合物被提出携带和激活猝灭色素玉米黄质，其可以从主体触角（LHCII）叶绿素中去除过量的激发能量（Holt等人，2005; Ahn等人，2008年）。另一种观点是，LHCII天线本身具有通过将其构象从光捕获状态改变为光保护状态来保护自身免受过度激发的固有能力（Ruban等人，2012年）。在高等植物的情况下，有人提出PSII天线的主要三聚体LHCII复合物发生聚集，这是由过量光照下光合膜上产生的质子梯度引发的（Ruban，2018）。聚合
Dear Editor, Oxygenic photosynthes is created the Biosphere as we know it. It allowed heterotrophic life, including ourselves, to flourish and supported it for millions of years. However, the delicate oxygenic photosynthetic machinery is susceptible to damage due to occasional, periodic, or constant exposure to intense light. Excess light causes absorption of too many photons by the light-harvesting antenna and overexcitation of its pigments that can damage the photosynthetic membrane, particularly the components of the oxygen-evolving PSII. This inhibits plant development and productivity. A physiological mechanism of photoprotection called nonphotochemical quenching (NPQ) is the major and fastest response carried out in the thylakoid membranes to harmlessly dissipate the excess light energy (Demmig-Adams et al., 2014). Two opposing views existed on the proteins, pigments, and dynamic processes involved in NPQ (Ruban et al., 2012). The recent work on LHCII minor antenna mutants revealed the truth.One view considers the existence of specific photoprotective pigment-protein complexes that are crucial in extinguishing excess photons in the light-harvesting antenna. These minor antenna complexes, composed of CP24, CP26, and CP29, are proposed to carry and activate the quenching pigment zeaxanthin that could remove excess excitation energy from the bulk antenna (LHCII) chlorophylls (Holt et al., 2005; Ahn et al., 2008). The other view is that the LHCII antenna itself possesses an inherent ability to protect itself against overexcitation by changing its conformation from a light-harvesting to a photoprotective state (Ruban et al., 2012). In the case of higher plants, it was proposed that the major trimeric LHCII complex of the PSII antenna undergoes aggregation, which is triggered by the proton gradient generated across the photosynthetic membrane in excess light (Ruban, 2018). The aggregated