Regulation and identity of florigen: FLOWERING LOCUS T moves center stage

Annu Rev Plant Biol. 2008;59:573-94. doi: 10.1146/annurev.arplant.59.032607.092755.


The transition from vegetative to reproductive growth is controlled by day length in many plant species. Day length is perceived in leaves and induces a systemic signal, called florigen, that moves through the phloem to the shoot apex. At the shoot apical meristem (SAM), florigen causes changes in gene expression that reprogram the SAM to form flowers instead of leaves. Analysis of flowering of Arabidopsis thaliana placed the CONSTANS/FLOWERING LOCUS T (CO/FT) module at the core of a pathway that promotes flowering in response to changes in day length. We describe progress in defining the molecular mechanisms that activate this module in response to changing day length and the increasing evidence that FT protein is a major component of florigen. Finally, we discuss conservation of FT function in other species and how variation in its regulation could generate different flowering behaviors.

Publication types

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

MeSH terms

  • Arabidopsis / physiology*
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology*
  • Arabidopsis Proteins / radiation effects
  • Flowers / physiology*
  • Gene Expression Regulation, Plant
  • Genetic Variation
  • MADS Domain Proteins / physiology*
  • MADS Domain Proteins / radiation effects
  • Photoperiod
  • Plant Leaves / physiology
  • Signal Transduction


  • Arabidopsis Proteins
  • FLF protein, Arabidopsis
  • MADS Domain Proteins