Cooperation of photosystem I with the plastoquinone pool in oxygen reduction in higher plant chloroplasts

The possible functions of a light-induced electron transfer to oxygen in the photosynthetic electron transport chain of higher plant chloroplasts are considered. The thermodynamic preconditions, as well as the experimental data about the participations of ferredoxin, the components of photosystems I...

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Bibliographic Details
Published in:Biochemistry (Moscow) 2008-01, Vol.73 (1), p.112
Main Author: Ivanov, B N
Format: Article
Language:English
Subjects:
Biochemistry
Botany
Chloroplasts
Hydrogen peroxide
Membranes
Oxygen
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Summary:The possible functions of a light-induced electron transfer to oxygen in the photosynthetic electron transport chain of higher plant chloroplasts are considered. The thermodynamic preconditions, as well as the experimental data about the participations of ferredoxin, the components of photosystems I and II, and plastoquinone in oxygen reduction are examined. It is concluded that, even in the presence of ferredoxin and ferredoxin + NADP^sup +^, oxygen reduction is carried out mainly by the membrane-bound carriers of the photosynthetic electron transport chain. The hypothesis is put forward that most superoxides, which are produced by reduction of O^sub 2^ molecules by the intramembrane components of the acceptor side of photosystem I, are reduced within the membrane by the plastohydroquinone molecules to the hydrogen peroxide. It is assumed that the H^sub 2^O^sub 2^ molecules that originate as the result of this process serve for signaling about the redox state of the plastoquinone pool. [PUBLICATION ABSTRACT]
ISSN:0006-2979
1608-3040
DOI:10.1007/s10541-008-1017-x