Toxic effects of antimony on photosystem II of Synechocystis sp. as probed by in vivo chlorophyll fluorescence

摘要

It has been demonstrated that antimony (Sb) at concentrations ranging from 1.0 to 10.0 mg L−1 inhibits O₂ evolution. Deeper insight into the influence of Sb on PSII was obtained with measurements of in vivo chlorophyll fluorescence. The donor and the acceptor sides of PSII were shown to be the target of Sb. Sb treatment induces inhibition of electron transport from Q_A− to Q_B/Q_B− and accumulation of P₆₈₀+. S₂(Q_AQ_B)− charge recombination and oxidation by PQ9 molecules became more important in Q_A− reoxidation as the electron transfer in PSII was inhibited. Sb exposure caused a steady increase in the proportion of PSII_X and PSII_β. These changes resulted in increased fluxes of dissipated energy and decreased index of photosynthesis performance, of maximum quantum yield, and of the overall photosynthetic driving force of PSII.