title: A voltage-dependent chloride channel fine-tunes photosynthesis in plants.
abstract: In natural habitats, plants frequently experience rapid changes in the intensity of sunlight. To cope with these changes and maximize growth, plants adjust photosynthetic light utilization in electron transport and photoprotective mechanisms. This involves a proton motive force (PMF) across the thylakoid membrane, postulated to be affected by unknown anion (Cl(-)) channels. Here we report that a bestrophin-like protein from Arabidopsis thaliana functions as a voltage-dependent Cl(-) channel in electrophysiological experiments. AtVCCN1 localizes to the thylakoid membrane, and fine-tunes PMF by anion influx into the lumen during illumination, adjusting electron transport and the photoprotective mechanisms. The activity of AtVCCN1 accelerates the activation of photoprotective mechanisms on sudden shifts to high light. Our results reveal that AtVCCN1, a member of a conserved anion channel family, acts as an early component in the rapid adjustment of photosynthesis in variable light environments.
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Andrei
authors.initials: A
authors.lastname: Herdean
authors.affiliation: Department of Biology, University of Padova, Padova 35121, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Teardo
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Anders K
authors.initials: AK
authors.lastname: Nilsson
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Bernard E
authors.initials: BE
authors.lastname: Pfeil
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Oskar N
authors.initials: ON
authors.lastname: Johansson
authors.affiliation: Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen 5232, Switzerland.|Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest 1121, Hungary.
authors.forename: Renáta
authors.initials: R
authors.lastname: Ünnep
authors.affiliation: Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen 5232, Switzerland.|Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest 1121, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Nagy
authors.affiliation: Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged 6701, Hungary.
authors.forename: Ottó
authors.initials: O
authors.lastname: Zsiros
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Somnath
authors.initials: S
authors.lastname: Dana
authors.affiliation: Department of Plant Anatomy, Eötvös Loránd University, Budapest 1117, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Solymosi
authors.affiliation: Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged 6701, Hungary.
authors.forename: Győző
authors.initials: G
authors.lastname: Garab
authors.affiliation: Department of Biology, University of Padova, Padova 35121, Italy.|CNR Neuroscience Institute, Padova 35121, Italy.
authors.forename: Ildikó
authors.initials: I
authors.lastname: Szabó
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Spetea
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Lundin
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018118:Chloride Channels / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D004579:Electron Transport / Q000502:physiology; D055724:Electrophysiological Phenomena; D008027:Light; D046529:Microscopy, Electron, Transmission; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010788:Photosynthesis / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000502:physiology; D018892:Proton-Motive Force / Q000502:physiology; D000072260:RNA Splicing Factors / Q000235:genetics / Q000378:metabolism*; D020524:Thylakoids / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D029681:Arabidopsis Proteins; D018118:Chloride Channels; D002712:Chlorides; D024101:Mitochondrial Proteins; D000072260:RNA Splicing Factors; C000605230:SLO3 protein, Arabidopsis