Interaction of LEAFY, AGAMOUS and TERMINAL FLOWER1 in Maintaining Floral Meristem Identity in Arabidopsis

Development. 2002 May;129(10):2519-27.

Abstract

The Arabidopsis transcription factor LEAFY acts upstream of homeotic genes such as AGAMOUS to confer floral identity on meristems that arise after the transition to reproductive development. Compared to the genetic circuitry regulating the establishment of floral meristem identity, little is known about its maintenance. Previous experiments with leafy heterozygous plants and agamous mutants grown in conditions that reduce the floral inductive stimulus have shown that both genes are required to prevent reversion of floral to inflorescence meristems. Here, we present evidence that LEAFY maintains floral meristem identity independently of AGAMOUS, and that the primary role of LEAFY is either direct repression of shoot identity genes or repression of an intermediate factor that activates shoot identity genes. The latter conclusions were deduced from the phenotypes conferred by a gain-of-function transgene, LEAFY:VP16, that appears to act as a dominant negative, or antimorphic, allele during maintenance of floral meristem identity. These observations contrast with previous findings that LEAFY acts as a direct activator of floral homeotic genes, supporting the hypothesis that the transcriptional activity of LEAFY is dependent on specific co-regulators.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AGAMOUS Protein, Arabidopsis / genetics*
  • AGAMOUS Protein, Arabidopsis / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis Proteins*
  • Biomarkers
  • Gene Expression Regulation, Plant
  • Herpes Simplex Virus Protein Vmw65 / genetics
  • Meristem / physiology*
  • Mutation
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transcription Factors*
  • Transcription, Genetic

Substances

  • AGAMOUS Protein, Arabidopsis
  • Arabidopsis Proteins
  • Biomarkers
  • Herpes Simplex Virus Protein Vmw65
  • LFY protein, Arabidopsis
  • Plant Proteins
  • Recombinant Fusion Proteins
  • TFL1 protein, Arabidopsis
  • Transcription Factors