miR156-regulated SPL transcription factors define an endogenous flowering pathway in Arabidopsis thaliana

Cell. 2009 Aug 21;138(4):738-49. doi: 10.1016/j.cell.2009.06.014.


The FT gene integrates several external and endogenous cues controlling flowering, including information on day length. A complex of the mobile FT protein and the bZIP transcription factor FD in turn has a central role in activating genes that execute the switch from vegetative to reproductive development. Here we reveal that microRNA156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes not only act downstream of FT/FD, but also define a separate endogenous flowering pathway. High levels of miR156 in young plants prevent precocious flowering. A subsequent day length-independent decline in miR156 abundance provides a permissive environment for flowering and is paralleled by a rise in SPL levels. At the shoot apex, FT/FD and SPLs converge on an overlapping set of targets, with SPLs directly activating flower-promoting MADS box genes, providing a molecular substrate for both the redundant activities and the feed-forward action of the miR156/SPL and FT/FD modules in flowering control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Flowers / genetics
  • Flowers / growth & development
  • Flowers / metabolism
  • Gene Expression Regulation, Plant*
  • Green Fluorescent Proteins / metabolism
  • Meristem / growth & development
  • MicroRNAs / metabolism*
  • Signal Transduction
  • Trans-Activators
  • Transcription Factors / metabolism*


  • Arabidopsis Proteins
  • FD protein, Arabidopsis
  • FT protein, Arabidopsis
  • MicroRNAs
  • SPL9 protein, Arabidopsis
  • Trans-Activators
  • Transcription Factors
  • Green Fluorescent Proteins