title: Non-photochemical quenching of fluorescence in cyanobacteria.
abstract: The pathways of energy dissipation of excessive absorbed energy in cyanobacteria in comparison with that in higher plants are discussed. Two mechanisms of non-photochemical quenching in cyanobacteria are described. In one case this quenching occurs as light-induced decrease of the fluorescence yield of long-wavelength chlorophylls of the photosystem I trimers induced by inactive reaction centers: P700 cation-radical or P700 in triplet state. In the other case, non-photochemical quenching in cyanobacteria takes place with contribution of water-soluble protein OCP (containing 3 -hydroxyechinenone) that induces reversible quenching of allophycocyanin fluorescence in phycobilisomes. The possible evolutionary pathways of the involvement of carotenoid-binding proteins in non-photochemical quenching are discussed comparing the cyanobacterial OCP and plant PsbS protein.
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia. nkarap@inbi.ras.ru
authors.forename: N V
authors.initials: NV
authors.lastname: Karapetyan
mesh_terms: D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll; D000458:Cyanobacteria / Q000378:metabolism*; D019281:Dimerization; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D008954:Models, Biological; D008968:Molecular Conformation; D010100:Oxygen / Q000378:metabolism*; D010777:Photochemistry / Q000379:methods; D010788:Photosynthesis; D045524:Phycobilisomes / Q000378:metabolism; D010798:Phycocyanin / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D046939:Synechocystis / Q000378:metabolism
chemical_list: D045342:Light-Harvesting Protein Complexes; D045524:Phycobilisomes; C002497:allophycocyanin; D010798:Phycocyanin; D002734:Chlorophyll; D002338:Carotenoids; D010100:Oxygen