REVIEW: Electron Transport in Chloroplasts: Regulation and Alternative Pathways of Electron Transfer

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Alexander N. Tikhonov^a

Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia

Received June 21, 2023; Revised July 9, 2023; Accepted July 9, 2023

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This work represents an overview of electron transport regulation in chloroplasts as considered in the context of structure-function organization of photosynthetic apparatus in plants. Main focus of the article is on bifurcated oxidation of plastoquinol by the cytochrome b₆f complex, which represents the rate-limiting step of electron transfer between photosystems II and I. Electron transport along the chains of non-cyclic, cyclic, and pseudocyclic electron flow, their relationships to generation of the trans-thylakoid difference in electrochemical potentials of protons in chloroplasts, and pH-dependent mechanisms of regulation of the cytochrome b₆f complex are considered. Redox reactions with participation of molecular oxygen and ascorbate, alternative mediators of electron transport in chloroplasts, have also been discussed.

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KEY WORDS: photosynthesis, chloroplasts, electron transport, regulation

DOI: 10.1134/S0006297923100036

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