Antagonistic roles of SEPALLATA3, FT and FLC genes as targets of the polycomb group gene CURLY LEAF

PLoS One. 2012;7(2):e30715. doi: 10.1371/journal.pone.0030715. Epub 2012 Feb 17.


In Arabidopsis, mutations in the Pc-G gene CURLY LEAF (CLF) give early flowering plants with curled leaves. This phenotype is caused by mis-expression of the floral homeotic gene AGAMOUS (AG) in leaves, so that ag mutations largely suppress the clf phenotype. Here, we identify three mutations that suppress clf despite maintaining high AG expression. We show that the suppressors correspond to mutations in FPA and FT, two genes promoting flowering, and in SEPALLATA3 (SEP3) which encodes a co-factor for AG protein. The suppression of the clf phenotype is correlated with low SEP3 expression in all case and reveals that SEP3 has a role in promoting flowering in addition to its role in controlling floral organ identity. Genetic analysis of clf ft mutants indicates that CLF promotes flowering by reducing expression of FLC, a repressor of flowering. We conclude that SEP3 is the key target mediating the clf phenotype, and that the antagonistic effects of CLF target genes masks a role for CLF in promoting flowering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Flowers / genetics
  • Flowers / physiology
  • Gene Expression Regulation, Plant
  • Genes, Plant / genetics*
  • Genetic Testing
  • Histones / metabolism
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • MADS Domain Proteins / genetics
  • MADS Domain Proteins / metabolism
  • Methylation
  • Mutation / genetics
  • Phenotype
  • Polycomb-Group Proteins
  • Repressor Proteins / genetics*
  • Suppression, Genetic
  • Time Factors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism


  • Arabidopsis Proteins
  • CURLY LEAF protein, Arabidopsis
  • FLF protein, Arabidopsis
  • FT protein, Arabidopsis
  • Histones
  • Homeodomain Proteins
  • MADS Domain Proteins
  • Polycomb-Group Proteins
  • Repressor Proteins
  • SEP3 protein, Arabidopsis
  • Transcription Factors