title: EPR study of light-induced regulation of photosynthetic electron transport in Synechocystis sp. strain PCC 6803.
abstract: The kinetics of the light-induced redox changes of the photosystem 1 (PS 1) primary donor P(700) in whole cells of the cyanobacteria Synechocystis sp. PCC 6803 were studied by the electron paramagnetic resonance method. It was shown that the linear photosynthetic electron transport in cyanobacteria was controlled by two main mechanisms: (i) oxygen-dependent acceleration of electron transfer from PS 1 to NADP(+) due to activation of the Calvin cycle reactions and (ii) retardation of electron flow between two photosystems governed by a transmembrane proton gradient. In addition to the linear photosynthetic electron transport, cyanobacteria were capable of maintaining alternative pathways involving cyclic electron transfer around PS 1 and respiratory chains.
authors.affiliation: Department of Biophysics, Faculty of Physics, M.V. Lomonosov Moscow State University, Russia.
authors.forename: Boris V
authors.initials: BV
authors.lastname: Trubitsin
authors.forename: Mahir D
authors.initials: MD
authors.lastname: Mamedov
authors.forename: Liya A
authors.initials: LA
authors.lastname: Vitukhnovskaya
authors.forename: Alexey Yu
authors.initials: AY
authors.lastname: Semenov
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Tikhonov
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003485:Cyanates / Q000494:pharmacology; D000458:Cyanobacteria / Q000378:metabolism*; D004237:Diuron / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004579:Electron Transport; D006540:Herbicides / Q000494:pharmacology; D007700:Kinetics; D008027:Light; D009249:NADP / Q000378:metabolism; D009550:Nigericin / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D011522:Protons; D013053:Spectrophotometry; D013997:Time Factors; D014466:Ultraviolet Rays; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003485:Cyanates; D006540:Herbicides; D011522:Protons; D014634:Valinomycin; D009249:NADP; D004237:Diuron; C024835:potassium cyanate; D009584:Nitrogen; D009550:Nigericin; D010100:Oxygen