title: Functional characterization of mutants affected in the carbonic anhydrase domain of the respiratory complex I in Arabidopsis thaliana.
abstract: The NADH-ubiquinone oxidoreductase complex (complex I) (EC 1.6.5.3) is the main entrance site of electrons into the respiratory chain. In a variety of eukaryotic organisms, except animals and fungi (Opisthokonta), it contains an extra domain comprising trimers of putative γ-carbonic anhydrases, named the CA domain, which has been proposed to be essential for assembly of complex I. However, its physiological role in plants is not fully understood. Here, we report that Arabidopsis mutants defective in two CA subunits show an altered photorespiratory phenotype. Mutants grown in ambient air show growth retardation compared to wild-type plants, a feature that is reversed by cultivating plants in a high-CO2 atmosphere. Moreover, under photorespiratory conditions, carbon assimilation is diminished and glycine accumulates, suggesting an imbalance with respect to photorespiration. Additionally, transcript levels of specific CA subunits are reduced in plants grown under non-photorespiratory conditions. Taken together, these results suggest that the CA domain of plant complex I contributes to sustaining efficient photosynthesis under ambient (photorespiratory) conditions.
authors.affiliation: Instituto de Investigaciones Biológicas IIB/CONICET, Universidad Nacional de Mar del Plata, cc 1245, 7600, Mar del Plata, Argentina.
authors.forename: Débora
authors.initials: D
authors.lastname: Soto
authors.affiliation: Instituto de Investigaciones Biológicas IIB/CONICET, Universidad Nacional de Mar del Plata, cc 1245, 7600, Mar del Plata, Argentina.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Córdoba
authors.affiliation: Instituto de Investigaciones Biológicas IIB/CONICET, Universidad Nacional de Mar del Plata, cc 1245, 7600, Mar del Plata, Argentina.
authors.forename: Fernando
authors.initials: F
authors.lastname: Villarreal
authors.affiliation: Instituto de Fisiología Vegetal, Universidad Nacional de La Plata/CONICET La Plata, cc 327, 1900, La Plata, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Bartoli
authors.affiliation: Plant Molecular Physiology and Biotechnology Group, Institute of Developmental and Molecular Biology of Plants, Cluster of Excellence on Plant Sciences, Heinrich Heine Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Schmitz
authors.affiliation: Plant Molecular Physiology and Biotechnology Group, Institute of Developmental and Molecular Biology of Plants, Cluster of Excellence on Plant Sciences, Heinrich Heine Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany.
authors.forename: Veronica G
authors.initials: VG
authors.lastname: Maurino
authors.affiliation: Institute for Plant Genetics, Leibniz Universität Hannover, Herrenhäuserstraße 2, D-30419, Hannover, Germany.
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Braun
authors.affiliation: Instituto de Investigaciones Biológicas IIB/CONICET, Universidad Nacional de Mar del Plata, cc 1245, 7600, Mar del Plata, Argentina.
authors.forename: Gabriela C
authors.initials: GC
authors.lastname: Pagnussat
authors.affiliation: Instituto de Investigaciones Biológicas IIB/CONICET, Universidad Nacional de Mar del Plata, cc 1245, 7600, Mar del Plata, Argentina.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Zabaleta
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000235:genetics / Q000378:metabolism*; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005998:Glycine / Q000378:metabolism; D009154:Mutation; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D017434:Protein Structure, Tertiary; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species; C579792:gammaCAL1 protein, Arabidopsis; C579793:gammaCAL2 protein, Arabidopsis; D002245:Carbon Dioxide; C000608070:CAL1 protein, Arabidopsis; C000608071:CAL2 protein, Arabidopsis; D002256:Carbonic Anhydrases; D042967:Electron Transport Complex I; D010100:Oxygen; D005998:Glycine
keywords: Arabidopsis thaliana; carbon recycling; mitochondria; photorespiration; γ-carbonic anhydrases