PGRL1 and LHCSR3 Compensate for Each Other in Controlling Photosynthesis and Avoiding Photosystem I Photoinhibition during High Light Acclimation of Chlamydomonas Cells

In natural environments, photosynthetic organisms experience frequent changes in the light supply, requiring modulation of light harvesting and electron transfer reactions to avoid mismatch between light conversion and metabolic reactions that may result in the production of harmful reactive oxygen species. They have thus evolved photoprotective regulatory mechanisms including the dissipation of excess energy (or non-photochemical quenching, NPQ), which relies on specific light-harvesting antennae, such as PSBS and Light-Harvesting Complex Stress-Related 3 (LHCSR3) (Peers et al., 2009), and is triggered by low pH in the thylakoid lumen.