title: Study of the effect of reducing conditions on the initial chlorophyll fluorescence rise in the green microalgae Chlamydomonas reinhardtii.
abstract: Incubation of Chlamydomonas reinhardtii cells under nutrient deficiency results in the faster initial rise in the light-induced chlorophyll fluorescence kinetic curve. We showed that short-term anaerobic incubation of algal cells altered initial fluorescence in a way similar to nutrient starvation, suggesting an important role of the plastoquinones redox state in the observed effect. Bi-component analysis of highly resolved initial fluorescence rise kinetics in sulfur- or oxygen-depleted C. reinhardtii cells suggested that one of the mechanisms underlying the observed phenomenon involves primary closure (photochemical inactivation via Qa reduction) of β-type PSII as compared to α-PSII. Moreover, results of modeling of the fluorescence curve brought us to the conclusion that accumulation of closed centers in α-PSII supercomplexes may also cause a faster initial fluorescence rise. The observed correlations between nutrient supply rate and initial fluorescence rise pattern in green algae can serve to characterize culture nutritional status in vivo.
authors.affiliation: Faculty of Biology, Moscow State University, Vorobyevi Gory, 119992 Moscow, Russia. taras_an@mail.ru
authors.forename: T K
authors.initials: TK
authors.lastname: Antal
authors.forename: A
authors.initials: A
authors.lastname: Kolacheva
authors.forename: A
authors.initials: A
authors.lastname: Maslakov
authors.forename: G Yu
authors.initials: GY
authors.lastname: Riznichenko
authors.forename: T E
authors.initials: TE
authors.lastname: Krendeleva
authors.forename: A B
authors.initials: AB
authors.lastname: Rubin
mesh_terms: D056804:Biofuels; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism*; D005453:Fluorescence; D007700:Kinetics; D008027:Light; D008954:Models, Biological; D010084:Oxidation-Reduction; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D010971:Plastoquinone / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*
chemical_list: D056804:Biofuels; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D013455:Sulfur; D010971:Plastoquinone