Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
Sci Rep. 2021 Apr 1;11(1):7415. doi: 10.1038/s41598-021-86975-9.
Photosynthesis is tightly regulated in order to withstand dynamic light environments. Under high light intensities, a mechanism known as non-photochemical quenching (NPQ) dissipates excess excitation energy, protecting the photosynthetic machinery from damage. An obstacle that lies in the way of understanding the molecular mechanism of NPQ is the large gap between in vitro and in vivo studies. On the one hand, the complexity of the photosynthetic membrane makes it challenging to obtain molecular information from in vivo experiments. On the other hand, a suitable in vitro system for the study of quenching is not available. Here we have developed a minimal NPQ system using proteoliposomes. With this, we demonstrate that the combination of low pH and PsbS is both necessary and sufficient to induce quenching in LHCII, the main antenna complex of plants. This proteoliposome system can be further exploited to gain more insight into how PsbS and other factors (e.g. zeaxanthin) influence the quenching mechanism observed in LHCII.
光合作用受到严格调控，以适应动态的光照环境。在高光强下，一种被称为非光化学猝灭（NPQ）的机制可以耗散多余的激发能，从而保护光合作用机器免受损伤。阻碍人们理解 NPQ 分子机制的一个障碍是体外和体内研究之间存在很大差距。一方面，光合膜的复杂性使得从体内实验中获取分子信息具有挑战性。另一方面，也没有合适的体外系统来研究猝灭。在这里，我们使用脂质体开发了一个最小的 NPQ 系统。通过这个系统，我们证明了低 pH 值和 PsbS 的结合对于诱导 LHCII 中的猝灭是必要且充分的，LHCII 是植物的主要天线复合物。这个脂质体系统可以进一步被利用，以深入了解 PsbS 和其他因素（如玉米黄质）如何影响 LHCII 中观察到的猝灭机制。
