title: Nonphotochemical quenching of chlorophyll fluorescence in Chlamydomonas reinhardtii.
abstract: Unlike plants, Chlamydomonas reinhardtii shows a restricted ability to develop nonphotochemical quenching upon illumination. Most of this limited quenching is due to state transitions instead of DeltapH-driven high-energy state quenching, qE. The latter could only be observed when the ability of the cells to perform photosynthesis was impaired, either by lowering temperature to approximately 0 degrees C or in mutants lacking RubisCO activity. Two main features were identified that account for the low level of qE in Chlamydomonas. On one hand, the electrochemical proton gradient generated upon illumination is apparently not sufficient to promote fluorescence quenching. On the other hand, the capacity to transduce the presence of a DeltapH into a quenching response is also intrinsically decreased in this alga, when compared to plants. The possible mechanism leading to these differences is discussed.
authors.affiliation: Unité Mixte de Recherche 7141 CNRS, Université Paris 6, Institut de Biologie Physico-Chimique, 75005 Paris, France. giovanni.finazzi@ibpc.fr
authors.forename: Giovanni
authors.initials: G
authors.lastname: Finazzi
authors.forename: Giles N
authors.initials: GN
authors.lastname: Johnson
authors.forename: Luca
authors.initials: L
authors.lastname: Dall'Osto
authors.forename: Francesca
authors.initials: F
authors.lastname: Zito
authors.forename: Giulia
authors.initials: G
authors.lastname: Bonente
authors.forename: Roberto
authors.initials: R
authors.lastname: Bassi
authors.forename: Francis-André
authors.initials: FA
authors.lastname: Wollman
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000737:chemistry / Q000528:radiation effects; D016825:Chlamydomonas reinhardtii / Q000737:chemistry* / Q000254:growth & development / Q000528:radiation effects; D002734:Chlorophyll / Q000737:chemistry* / Q000528:radiation effects; D005453:Fluorescence; D008027:Light; D010777:Photochemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D002734:Chlorophyll