* To whom correspondence should be addressed.
Received November 22, 2013; Revision received December 16, 2013
Photosystem II (PSII) is a pigment–protein complex of thylakoid membrane of higher plants, algae, and cyanobacteria where light energy is used for oxidation of water and reduction of plastoquinone. Light-dependent reactions (generation of excited states of pigments, electron transfer, water oxidation) taking place in PSII can lead to the formation of reactive oxygen species. In this review attention is focused on the problem of interaction of molecular oxygen with the donor site of PSII, where after the removal of manganese from the water-oxidizing complex illumination induces formation of long-lived states (P680+• and TyrZ•) capable of oxidizing surrounding organic molecules to form radicals.
KEY WORDS: photosystem II, reactive oxygen species, manganese, hydroperoxides