REVIEW: Non-photochemical Quenching of Fluorescence in Cyanobacteria

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N. V. Karapetyan

Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, 119071 Moscow, Russia; fax: (495) 954-2732; E-mail: nkarap@inbi.ras.ru

Received May 7, 2007

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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.

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KEY WORDS: allophycocyanin, cyanobacteria, 3´-hydroxyechinenone, light-harvesting complex LHCII, non-photochemical quenching, orange carotenoid-binding protein, phycobilisome

DOI: 10.1134/S0006297907100100

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