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Biochim Biophys Acta. 2014 Jun;1837(6):825-34. doi: 10.1016/j.bbabio.2014.01.024. Epub 2014 Feb 4.

Redox and ATP control of photosynthetic cyclic electron flow in Chlamydomonas reinhardtii: (II) involvement of the PGR5-PGRL1 pathway under anaerobic conditions.

Author information

1
UMR 7141, CNRS et Université Pierre et Marie Curie (Paris VI), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France. Electronic address: jean.alric@cea.fr.

Abstract

In oxygenic photosynthesis, cyclic electron flow around photosystem I denotes the recycling of electrons from stromal electron carriers (reduced nicotinamide adenine dinucleotide phosphate, NADPH, ferredoxin) towards the plastoquinone pool. Whether or not cyclic electron flow operates similarly in Chlamydomonas and plants has been a matter of debate. Here we would like to emphasize that despite the regulatory or metabolic differences that may exist between green algae and plants, the general mechanism of cyclic electron flow seems conserved across species. The most accurate way to describe cyclic electron flow remains to be a redox equilibration model, while the supramolecular reorganization of the thylakoid membrane (state transitions) has little impact on the maximal rate of cyclic electron flow. The maximum capacity of the cyclic pathways is shown to be around 60 electrons transferred per photosystem per second, which is in Chlamydomonas cells treated with 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and placed under anoxic conditions. Part I of this work (aerobic conditions) was published in a previous issue of BBA-Bioenergetics (vol. 1797, pp. 44-51) (Alric et al., 2010).

KEYWORDS:

Chlamydomonas reinhardtii; Cytochrome b(6)f; Electron transfer; Green algae; Photosystem I

PMID:
24508216
DOI:
10.1016/j.bbabio.2014.01.024
[Indexed for MEDLINE]
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