title: Brahma is required for proper expression of the floral repressor FLC in Arabidopsis.
abstract: BACKGROUND
  BRAHMA (BRM) is a member of a family of ATPases of the SWI/SNF chromatin remodeling complexes from Arabidopsis. BRM has been previously shown to be crucial for vegetative and reproductive development.
  
  
  RESULTS
  Here we carry out a detailed analysis of the flowering phenotype of brm mutant plants which reveals that, in addition to repressing the flowering promoting genes CONSTANS (CO), FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1), BRM also represses expression of the general flowering repressor FLOWERING LOCUS C (FLC). Thus, in brm mutant plants FLC expression is elevated, and FLC chromatin exhibits increased levels of histone H3 lysine 4 tri-methylation and decreased levels of H3 lysine 27 tri-methylation, indicating that BRM imposes a repressive chromatin configuration at the FLC locus. However, brm mutants display a normal vernalization response, indicating that BRM is not involved in vernalization-mediated FLC repression. Analysis of double mutants suggests that BRM is partially redundant with the autonomous pathway. Analysis of genetic interactions between BRM and the histone H2A.Z deposition machinery demonstrates that brm mutations overcome a requirement of H2A.Z for FLC activation suggesting that in the absence of BRM, a constitutively open chromatin conformation renders H2A.Z dispensable.
  
  
  CONCLUSIONS
  BRM is critical for phase transition in Arabidopsis. Thus, BRM represses expression of the flowering promoting genes CO, FT and SOC1 and of the flowering repressor FLC. Our results indicate that BRM controls expression of FLC by creating a repressive chromatin configuration of the locus.
authors: Max Planck Institute for Plant Breeding, Cologne, Germany. farrona@mpipz.mpg.de
authors: Sara
authors: S
authors: Farrona
authors: Lidia
authors: L
authors: Hurtado
authors: Rosana
authors: R
authors: March-Díaz
authors: Robert J
authors: RJ
authors: Schmitz
authors: Francisco J
authors: FJ
authors: Florencio
authors: Franziska
authors: F
authors: Turck
authors: Richard M
authors: RM
authors: Amasino
authors: José C
authors: JC
authors: Reyes
mesh_terms: D000251:Adenosine Triphosphatases / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D047369:Chromatin Immunoprecipitation; D017440:Photoperiod
chemical_list: D029681:Arabidopsis Proteins; D000251:Adenosine Triphosphatases; C514541:BRM protein, Arabidopsis