REVIEW: Superoxide Anion Radical Generation in Photosynthetic Electron Transport Chain

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Marina A. Kozuleva^1,a* and Boris N. Ivanov¹

¹Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia

^* To whom correspondence should be addressed.

Received May 9, 2023; Revised June 16, 2023; Accepted June 18, 2023

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This review analyzes data available in the literature on the rates, characteristics, and mechanisms of oxygen reduction to a superoxide anion radical at the sites of photosynthetic electron transport chain where this reduction has been established. The existing assumptions about the role of the components of these sites in this process are critically examined using thermodynamic approaches and results of the recent studies. The process of O₂ reduction at the acceptor side of PSI, which is considered the main site of this process taking place in the photosynthetic chain, is described in detail. Evolution of photosynthetic apparatus in the context of controlling the leakage of electrons to O₂ is explored. The reasons limiting application of the results obtained with the isolated segments of the photosynthetic chain to estimate the rates of O₂ reduction at the corresponding sites in the intact thylakoid membrane are discussed.

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KEY WORDS: photosynthesis, photosynthetic electron transport chain, oxygen reduction, superoxide radical

DOI: 10.1134/S0006297923080011

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