AUXIN RESPONSE FACTOR 3 integrates the functions of AGAMOUS and APETALA2 in floral meristem determinacy

Plant J. 2014 Nov;80(4):629-41. doi: 10.1111/tpj.12658. Epub 2014 Oct 1.

Abstract

In Arabidopsis, AUXIN RESPONSE FACTOR 3 (ARF3) belongs to the auxin response factor (ARF) family that regulates the expression of auxin-responsive genes. ARF3 is known to function in leaf polarity specification and gynoecium patterning. In this study, we discovered a previously unknown role for ARF3 in floral meristem (FM) determinacy through the isolation and characterization of a mutant of ARF3 that enhanced the FM determinacy defects of agamous (ag)-10, a weak ag allele. Central players in FM determinacy include WUSCHEL (WUS), a gene critical for FM maintenance, and AG and APETALA2 (AP2), which regulate FM determinacy by repression and promotion of WUS expression, respectively. We showed that ARF3 confers FM determinacy through repression of WUS expression, and associates with the WUS locus in part in an AG-dependent manner. We demonstrated that ARF3 is a direct target of AP2 and partially mediates AP2's function in FM determinacy. ARF3 exhibits dynamic and complex expression patterns in floral organ primordia; altering the patterns spatially compromised FM determinacy. This study uncovered a role for ARF3 in FM determinacy and revealed relationships among genes in the genetic network governing FM determinacy.

Keywords: AGAMOUS; APETALA2; AUXIN RESPONSE FACTOR 3; Arabidopsis; WUSCHEL; floral determinacy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AGAMOUS Protein, Arabidopsis / genetics
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Flowers / genetics
  • Flowers / metabolism
  • Gene Expression Regulation, Plant
  • Gene Regulatory Networks
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Meristem / genetics
  • Meristem / metabolism*
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Plants, Genetically Modified

Substances

  • AGAMOUS Protein, Arabidopsis
  • APETALA2 protein, Arabidopsis
  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • ETT protein, Arabidopsis
  • Homeodomain Proteins
  • Nuclear Proteins
  • WUSCHEL protein, Arabidopsis