MGOUN3: Evidence for chromatin-mediated regulation of FLC expression

Soazig Guyomarc'h, Moussa Benhamed, Gaëtan Lemonnier, Jean Pierre Renou, Dao Xiu Zhou, Marianne Delarue*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


The MGOUN3(MGO3)/BRUSHY1(BRU1)/TONSOKU(TSK) gene of Arabidopsis thaliana encodes a nuclear leucine-glycine-asparagine (LGN) domain protein that may be implicated in chromatin dynamics and genome maintenance. Mutants with defects in MGO3 display a fasciated stem and disorganized meristem structures. The transition to flowering was examined in mgo3 mutants and it was found that, under short days, the mutants flowered significantly earlier than the wild-type plants. Study of flowering-time associated gene expression showed that the floral transition inhibitor gene FLC was under-expressed in the mutant background. Ectopic expression of the flower-specific genes AGAMOUS (AG), PISTILLATA (PI), and SEPALLATA3 (SEP3) in mgo3 vegetative organs was also detected. Western blot and chromatin immunoprecipitation experiments suggested that histone H3 acetylation may be altered in the mgo3 background. Together, these data suggest that MGO3 is required for the correct transition to flowering and that this may be mediated by histone acetylation and associated changes in FLC expression.

Original languageEnglish (US)
Pages (from-to)2111-2119
Number of pages9
JournalJournal of Experimental Botany
Issue number9
StatePublished - Jun 1 2006


  • Arabidopsis thaliana
  • BRU1
  • Chromatin dynamics
  • FLC
  • Histone modifications
  • MGO3
  • TSK

ASJC Scopus subject areas

  • Physiology
  • Plant Science

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