title: Mutations in the Arabidopsis SWC6 gene, encoding a component of the SWR1 chromatin remodelling complex, accelerate flowering time and alter leaf and flower development.
abstract: Mutations affecting the Arabidopsis SWC6 gene encoding a putative orthologue of a component of the SWR1 chromatin remodelling complex in plants have been characterized. swc6 mutations cause early flowering, shortened inflorescence internodes, and altered leaf and flower development. These phenotypic defects resemble those of the photoperiod independent early flowering 1 (pie1) and early in short days 1 (esd1) mutants, also affected in homologues of the SWR1 complex subunits. SWC6 is a ubiquitously expressed nuclear HIT-Zn finger-containing protein, with the highest levels found in pollen. Double mutant analyses suggest that swc6 abolishes the FLC-mediated late-flowering phenotype of plants carrying active alleles of FRI and of mutants of the autonomous pathway. It was found that SWC6 is required for the expression of the FLC repressor to levels that inhibit flowering. However, the effect of swc6 in an flc null background and the down-regulation of other FLC-like/MAF genes in swc6 mutants suggest that flowering inhibition mediated by SWC6 occurs through both FLC- and FLC-like gene-dependent pathways. Both genetic and physical interactions between SWC6 and ESD1 have been demonstrated, suggesting that both proteins act in the same complex. Using chromatin immunoprecipitation, it has been determined that SWC6, as previously shown for ESD1, is required for both histone H3 acetylation and H3K4 trimethylation of the FLC chromatin. Altogether, these results suggest that SWC6 and ESD1 are part of an Arabidopsis SWR1 chromatin remodelling complex involved in the regulation of diverse aspects of plant development, including floral repression through the activation of FLC and FLC-like genes.
authors.affiliation: Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Centro de Biotecnologia y Genómica de Plantas (INIA-UAU), Ctra. de A Coruña, Km 7,5, Madrid 28040, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Lázaro
authors.forename: Angeles
authors.initials: A
authors.lastname: Gómez-Zambrano
authors.forename: Leticia
authors.initials: L
authors.lastname: López-González
authors.forename: Manuel
authors.initials: M
authors.lastname: Piñeiro
authors.forename: Jose A
authors.initials: JA
authors.lastname: Jarillo
mesh_terms: D000107:Acetylation; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000254:growth & development*; D051548:Histone Acetyltransferases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D026161:MADS Domain Proteins / Q000378:metabolism*; D008745:Methylation; D008840:Microfilament Proteins / Q000378:metabolism*; D009154:Mutation; D018515:Plant Leaves / Q000254:growth & development*
chemical_list: C507995:ARP6 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C418902:At5g10140 protein, Arabidopsis; C414613:FRI protein, Arabidopsis; D006657:Histones; D026161:MADS Domain Proteins; D008840:Microfilament Proteins; C529050:SWC6 protein, Arabidopsis; D051548:Histone Acetyltransferases