title: SNOWY COTYLEDON 2 Promotes Chloroplast Development and Has a Role in Leaf Variegation in Both Lotus japonicus and Arabidopsis thaliana.
abstract: Plants contain various factors that transiently interact with subunits or intermediates of the thylakoid multiprotein complexes, promoting their stable association and integration. Hence, assembly factors are essential for chloroplast development and the transition from heterotrophic to phototrophic growth. Snowy cotyledon 2 (SCO2) is a DNAJ-like protein involved in thylakoid membrane biogenesis and interacts with the light-harvesting chlorophyll-binding protein LHCB1. In Arabidopsis thaliana, SCO2 function was previously reported to be restricted to cotyledons. Here we show that disruption of SCO2 in Lotus japonicus results not only in paler cotyledons but also in variegated true leaves. Furthermore, smaller and pale-green true leaves can also be observed in A. thaliana sco2 (atsco2) mutants under short-day conditions. In both species, SCO2 is required for proper accumulation of PSII-LHCII complexes. In contrast to other variegated mutants, inhibition of chloroplastic translation strongly affects L. japonicus sco2 mutant development and fails to suppress their variegated phenotype. Moreover, inactivation of the suppressor of variegation AtClpR1 in the atsco2 background results in an additive double-mutant phenotype with variegated true leaves. Taken together, our results indicate that SCO2 plays a distinct role in PSII assembly or repair and constitutes a novel factor involved in leaf variegation.
authors.affiliation: Plant Molecular Biology, Department of Biology I, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany; Copenhagen Plant Science Center, University of Copenhagen, 1871 Frederiksberg C, Denmark; Research and Innovation Center, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all'Adige, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Zagari
authors.affiliation: Copenhagen Plant Science Center, University of Copenhagen, 1871 Frederiksberg C, Denmark.
authors.forename: Omar
authors.initials: O
authors.lastname: Sandoval-Ibañez
authors.affiliation: Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Sandal
authors.affiliation: Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark.
authors.forename: Junyi
authors.initials: J
authors.lastname: Su
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Rodriguez-Concepcion
authors.affiliation: Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Stougaard
authors.affiliation: Copenhagen Plant Science Center, University of Copenhagen, 1871 Frederiksberg C, Denmark.
authors.forename: Mathias
authors.initials: M
authors.lastname: Pribil
authors.affiliation: Plant Molecular Biology, Department of Biology I, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany; Copenhagen Plant Science Center, University of Copenhagen, 1871 Frederiksberg C, Denmark. Electronic address: leister@lmu.de.
authors.forename: Dario
authors.initials: D
authors.lastname: Leister
authors.affiliation: Plant Molecular Biology, Department of Biology I, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany; Copenhagen Plant Science Center, University of Copenhagen, 1871 Frederiksberg C, Denmark.
authors.forename: Pablo
authors.initials: P
authors.lastname: Pulido
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D002736:Chloroplasts / Q000502:physiology*; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry; D000070116:Lotus / Q000235:genetics / Q000254:growth & development*; D009154:Mutation; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D050956:HSP40 Heat-Shock Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D019704:Protein Disulfide-Isomerases; C000623304:SCO2 protein, Arabidopsis
keywords: DNAJ-like; SCO2; assembly factor; chloroplast development; photosynthesis; variegation