title: The absence of chlorophyll b affects lateral mobility of photosynthetic complexes and lipids in grana membranes of Arabidopsis and barley chlorina mutants.
abstract: The lateral mobility of integral components of thylakoid membranes, such as plastoquinone, xanthophylls, and pigment-protein complexes, is critical for the maintenance of efficient light harvesting, high rates of linear electron transport, and successful repair of damaged photosystem II (PSII). The packaging of the photosynthetic pigment-protein complexes in the membrane depends on their size and stereometric parameters which in turn depend on the composition of the complexes. Chlorophyll b (Chlb) is an important regulator of antenna size and composition. In this study, the lateral mobility (the mobile fraction size) of pigment-protein complexes and lipids in grana membranes was analyzed in chlorina mutants of Arabidopsis and barley lacking Chlb. In the Arabidopsis ch1-3 mutant, diffusion of membrane lipids decreased as compared to wild-type plants, but the diffusion of photosynthetic complexes was not affected. In the barley chlorina f2 3613 mutant, the diffusion of pigment-protein complexes significantly decreased, while the diffusion of lipids increased, as compared to wild-type plants. We propose that the size of the mobile fractions of pigment-protein complexes in grana membranes in vivo is higher than reported previously. The data are discussed in the context of the protein composition of antennae, characteristics of the plastoquinone pool, and production of reactive oxygen species in leaves of chlorina mutants.
authors.affiliation: Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376, Saint-Petersburg, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Tyutereva
authors.affiliation: Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376, Saint-Petersburg, Russia.
authors.forename: Anastasiia I
authors.initials: AI
authors.lastname: Evkaikina
authors.affiliation: Laboratory of Plant Anatomy and Morphology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376, Saint-Petersburg, Russia.
authors.forename: Alexandra N
authors.initials: AN
authors.lastname: Ivanova
authors.affiliation: Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376, Saint-Petersburg, Russia. ovoitse@binran.ru.
authors.forename: Olga V
authors.identifier: http://orcid.org/0000-0003-0966-1270
authors.initials: OV
authors.lastname: Voitsekhovskaja
mesh_terms: D017360:Arabidopsis / Q000378:metabolism* / Q000528:radiation effects; D002734:Chlorophyll / Q000378:metabolism*; D005453:Fluorescence; D036681:Fluorescence Recovery After Photobleaching; D001467:Hordeum / Q000378:metabolism* / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism; D008055:Lipids / Q000737:chemistry*; D009154:Mutation / Q000235:genetics*; D010105:Oxygenases / Q000378:metabolism; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects; D010971:Plastoquinone / Q000378:metabolism; D020524:Thylakoids / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D045342:Light-Harvesting Protein Complexes; D008055:Lipids; D002734:Chlorophyll; C037184:chlorophyll b; D010105:Oxygenases; C115272:chlorophyll a oxygenase; D010971:Plastoquinone
keywords: Chlorina mutants; Chlorophyll b; FRAP; Hordeum vulgare; Lateral mobility; Plastoquinone