Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, Fogg Building, Mile End Road, London E1 4NS, UK.
Plant Cell Physiol. 2021 Oct 29;62(7):1063-1072. doi: 10.1093/pcp/pcaa155.
Non-photochemical chlorophyll fluorescence quenching (NPQ) remains one of the most studied topics of the 21st century in photosynthesis research. Over the past 30 years, profound knowledge has been obtained on the molecular mechanism of NPQ in higher plants. First, the largely overlooked significance of NPQ in protecting the reaction center of photosystem II (RCII) against damage, and the ways to assess its effectiveness are highlighted. Then, the key in vivo signals that can monitor the life of the major NPQ component, qE, are presented. Finally, recent knowledge on the site of qE and the possible molecular events that transmit ΔpH into the conformational change in the major LHCII [the major trimeric light harvesting complex of photosystem II (PSII)] antenna complex are discussed. Recently, number of reports on Arabidopsis mutants lacking various antenna components of PSII confirmed that the in vivo site of qE rests within the major trimeric LHCII complex. Experiments on biochemistry, spectroscopy, microscopy and molecular modeling suggest an interplay between thylakoid membrane geometry and the dynamics of LHCII, the PsbS (PSII subunit S) protein and thylakoid lipids. The molecular basis for the qE-related conformational change in the thylakoid membrane, including the possible onset of a hydrophobic mismatch between LHCII and lipids, potentiated by PsbS protein, begins to unfold.
非光化学猝灭（NPQ）仍然是 21 世纪光合作用研究中最受关注的课题之一。在过去的 30 年里，人们对高等植物 NPQ 的分子机制有了深刻的认识。首先，强调了 NPQ 在保护光系统 II（RCII）反应中心免受损伤方面的重要性，以及评估其有效性的方法。然后，介绍了可以监测主要 NPQ 组分 qE 生命的关键体内信号。最后，讨论了最近关于 qE 位点和可能的分子事件的知识，这些事件将 ΔpH 传递到主要捕光复合物 II（PSII）天线复合物中构象变化的位置。最近，许多关于拟南芥突变体缺乏 PSII 各种天线组分的报告证实，qE 的体内位置位于主要三聚体 LHCII 复合物内。生物化学、光谱学、显微镜和分子建模实验表明，类囊体膜几何形状与 LHCII、PsbS（PSII 亚基 S）蛋白和类囊体脂质的动力学之间存在相互作用。包括 PsbS 蛋白促进的 LHCII 与脂质之间可能发生疏水性失配在内的与 qE 相关的类囊体膜构象变化的分子基础开始显现。
