AINTEGUMENTA and AINTEGUMENTA-LIKE6 act redundantly to regulate Arabidopsis floral growth and patterning

Plant Physiol. 2009 Aug;150(4):1916-29. doi: 10.1104/pp.109.141119. Epub 2009 Jun 19.


An Arabidopsis (Arabidopsis thaliana) flower consists of four types of organs arranged in a stereotypical pattern. This complex floral structure is elaborated from a small number of floral meristem cells partitioned from the shoot apical meristem during reproductive development. The positioning of floral primordia within the periphery of the shoot apical meristem depends on transport of the phytohormone auxin with floral anlagen arising at sites of auxin maxima. An early marker of lateral organ fate is the AP2/ERF-type transcription factor AINTEGUMENTA (ANT), which has been proposed to act downstream of auxin in organogenic growth. Here, I show that the related, AINTEGUMENTA-LIKE6 (AIL6)/PLETHORA3 gene acts redundantly with ANT during flower development. ant ail6 double mutants show defects in floral organ positioning, identity, and growth. These floral defects are correlated with changes in the expression levels and patterns of two floral organ identity genes, APETALA3 and AGAMOUS. ant ail6 flowers also display altered expression of an auxin-responsive reporter, suggesting that auxin accumulation and/or responses are not normal. Furthermore, I show that ANT expression in incipient and young floral primordia depends on auxin transport within the inflorescence meristem. These results show that ANT and AIL6 are important regulators of floral growth and patterning and that they may act downstream of auxin in these processes.

Publication types

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

MeSH terms

  • AGAMOUS Protein, Arabidopsis / genetics
  • AGAMOUS Protein, Arabidopsis / metabolism
  • Arabidopsis / drug effects
  • Arabidopsis / embryology*
  • Arabidopsis / genetics
  • Arabidopsis / ultrastructure
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Biological Transport / drug effects
  • Body Patterning* / drug effects
  • Cell Proliferation / drug effects
  • Flowers / cytology
  • Flowers / genetics
  • Flowers / growth & development*
  • Flowers / ultrastructure
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Reporter
  • Glucuronidase / metabolism
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Indoleacetic Acids / metabolism
  • Indoleacetic Acids / pharmacology
  • MADS Domain Proteins / genetics
  • MADS Domain Proteins / metabolism
  • Meristem / cytology
  • Meristem / drug effects
  • Meristem / growth & development
  • Meristem / ultrastructure
  • Models, Biological
  • Mutation / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • AGAMOUS Protein, Arabidopsis
  • AINTEGUMENTA protein, Arabidopsis
  • APETALA 3 protein, Arabidopsis
  • Arabidopsis Proteins
  • Homeodomain Proteins
  • Indoleacetic Acids
  • LFY protein, Arabidopsis
  • MADS Domain Proteins
  • PLT3 protein, Arabidopsis
  • Transcription Factors
  • WUSCHEL protein, Arabidopsis
  • Glucuronidase