The high chlorophyll fluorescence 244 (HCF244) Is potentially involved in glutathione peroxidase 7-regulated high light stress in Arabidopsis thaliana

Glutathione peroxidases (GPXs) are key enzymes of the antioxidant network in plants. In this study, we show that mutations in the Arabidopsis thaliana GPX7 gene result in increased photo-bleaching under high light (HL) condition compared to wild type (WT) plants. Moreover, GPX7 possesses peroxidase activity and GPX7-deficient mutants are hypersensitive to hydrogen peroxide. GPX7 protein is located in the chloroplast stroma and thylakoid membrane and GPX7 expression is strongly induced by HL. Yeast two-hybrid screening identified a member of the atypical short-chain dehydrogenase/reductase superfamily, high chlorophyll fluorescence phenotype 244 (HCF244), a protein involved in photosystem II biogenesis, as a putative GPX7 interactor. Moreover, the photosynthetic efficiency and the accumulation of HCF244 and D1 proteins, the key component of photosystem II reaction center, are decreased in gpx7–1 comparing with WT plants under HL treatment. These results suggest that HCF244 might play roles in GPX7-mediated HL-induced photo-oxidation repair system.