Damage to the oxygen-evolving complex by superoxide anion, hydrogen peroxide, and hydroxyl radical in photoinhibition of photosystem II.
Under strong illumination of a photosystem II (PSII) membrane, endogenous superoxide anion, hydrogen peroxide, and hydroxyl radical were successively produced. These compounds then cooperatively resulted in a release of manganese from the oxygen-evolving complex (OEC) and an inhibition of oxygen evolution activity. The OEC inactivation was initiated by an acceptor-side generated superoxide anion, and hydrogen peroxide was most probably responsible for the transportation of reactive oxygen species (ROS) across the PSII membrane from the acceptor-side to the donor-side. Besides ROS being generated in the acceptor-side induced manganese loss; there may also be a ROS-independent manganese loss in the OEC of PSII. Both superoxide anion and hydroxyl radical located inside the PSII membrane were directly identified by a spin trapping-electron spin resonance (ESR) method in combination with a lipophilic spin trap, 5-(diethoxyphosphoryl)-5-phenethyl-1-pyrroline N-oxide (DEPPEPO). The endogenous hydrogen peroxide production was examined by oxidation of thiobenzamide.
Song
Yu Guang
YG
State Key laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing, 100080, China.
Liu
Bin
B
Wang
Lan Fen
LF
Li
Mai He
MH
Liu
Yang
Y
D004578:Electron Spin Resonance Spectroscopy; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000494:pharmacology*; D007700:Kinetics; D008027:Light; D010100:Oxygen / Q000378:metabolism*; D045332:Photosystem II Protein Complex / Q000187:drug effects / Q000502:physiology*; D018724:Spinacia oleracea / Q000378:metabolism* / Q000528:radiation effects; D013481:Superoxides / Q000494:pharmacology*
D045332:Photosystem II Protein Complex; D013481:Superoxides; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D010100:Oxygen