1. Maximal cyclic electron flow rate is independent of PGRL1 in Chlamydomonas
- Author
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Wojciech J. Nawrocki, F.-A. Wollman, Fabrice Rappaport, Benjamin Bailleul, Pierre Joliot, Pierre Cardol, Physiologie membranaire et moléculaire du chloroplaste (PMMC), Sorbonne Université (SU)-Institut de biologie physico-chimique (IBPC (FR_550)), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Liège, Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF (institution)), Biologie du chloroplaste et perception de la lumière chez les micro-algues, Institut de biologie physico-chimique (IBPC (FR_550)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and European Project: 682580,H2020,ERC-2015-CoG,BEAL(2016)
- Subjects
0106 biological sciences ,0301 basic medicine ,animal structures ,photosystem I ,Biophysics ,Chlamydomonas reinhardtii ,Photosystem I ,Photosynthesis ,01 natural sciences ,Biochemistry ,Redox ,Electron Transport ,03 medical and health sciences ,Oxidoreductase ,[CHIM]Chemical Sciences ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,biology ,Chemistry ,Cytochrome b6f complex ,Chlamydomonas ,Wild type ,Membrane Proteins ,anoxia ,Cell Biology ,biology.organism_classification ,cyclic electron flow ,030104 developmental biology ,embryonic structures ,cytochrome b6f ,Oxidation-Reduction ,010606 plant biology & botany - Abstract
International audience; Cyclic electron flow (CEF) is defined as a return of the reductants from the acceptor side of Photosystem I (PSI) to the pool of its donors via the cytochrome b6f. It is described to be complementary to the linear electron flow and essential for photosynthesis. However, despite many efforts aimed to characterize CEF, its pathway and its regulation modes remain equivocal, and its physiological significance is still not clear. Here we use novel spectroscopic to measure the rate of CEF at the onset of light in the green alga Chlamydomonas reinhardtii. The initial redox state of the photosynthetic chain or the oxygen concentration do not modify the initial maximal rate of CEF (60 electrons per second per PSI) but rather strongly influence its duration. Neither the maximal rate nor the duration of CEF are different in the pgrl1 mutant compared to the wild type, disqualifying PGRL1 as the ferredoxin-plastoquinone reductase involved in the CEF mechanism.
- Published
- 2019