No abstract

Background: PSII is a protein complex that captures sunlight to drive water oxidation. Results: Cyanidioschyzon merolae PSII is protected by reversible reaction center-based non-photochemical quenching. Conclusion: C. merolae PSII employs reaction center non-photochemical quenching as the main photoprotective mechanism. Significance: We provide the first direct evidence of the PSII reaction center as the primary locus of non-photochemical quenching in the extremophilic red algae.