Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
Photosynth Res. 2022 Jun;152(3):275-281. doi: 10.1007/s11120-022-00907-w. Epub 2022 Mar 18.
Photoprotection by non-photochemical quenching is important for optimal growth and development, especially during dynamic changes of the light intensity. The main component responsible for energy dissipation is called qE. It has been proposed that qE involves the reorganization of the photosynthetic complexes and especially of Photosystem II. However, despite a number of studies, there are still contradictory results concerning the structural changes in PSII during qE induction. The main limitation in addressing this point is the very fast nature of the off switch of qE, since the illumination is usually performed in folio and the preparation of the thylakoids requires a dark period. To avoid qE relaxation during thylakoid isolation, in this work quenching was induced directly on isolated and functional thylakoids that were then solubilized in the light. The analysis of the quenched thylakoids in native gel showed only a small decrease in the large PSII supercomplexes (CSM/CSM) which is most likely due to photoinhibition/light acclimation since it does not recover in the dark. This result indicates that qE rise is not accompanied by a structural disassembly of the PSII supercomplexes.
非光化学猝灭的光保护对于最佳的生长和发育非常重要，特别是在光强度的动态变化期间。负责能量耗散的主要成分称为 qE。已经提出 qE 涉及光合作用复合物的重新组织，特别是光系统 II。然而，尽管进行了许多研究，但在 qE 诱导期间 PSII 结构变化方面仍存在相互矛盾的结果。解决这一问题的主要限制是 qE 关闭开关非常快，因为照明通常在叶片上进行，并且制备类囊体需要暗期。为了避免在类囊体分离过程中 qE 松弛，在这项工作中直接在分离和功能正常的类囊体上诱导猝灭，然后在光下溶解它们。在天然凝胶中分析猝灭的类囊体时，仅观察到大 PSII 超复合物（CSM/CSM）略有减少，这很可能是由于光抑制/光驯化所致，因为在黑暗中不会恢复。这一结果表明，qE 的上升并不伴随着 PSII 超复合物的结构解体。
