HEN1 functions pleiotropically in Arabidopsis development and acts in C function in the flower

Development. 2002 Mar;129(5):1085-94. doi: 10.1242/dev.129.5.1085.


Four classes of floral homeotic MADS domain proteins specify the identities of the four organ types in an Arabidopsis flower. While the activities of the MADS domain proteins are essentially confined to the flower or to the inflorescence, several genes, such as APETALA2, HUA1 and HUA2, also act outside the flower in addition to their organ identity functions inside the flower. We identified a new gene, HUA ENHANCER 1 (HEN1) from a sensitized genetic screen in the hua1-1 hua2-1 background that is compromised in floral homeotic C function. We showed that HEN1, like the C function gene AGAMOUS, acts to specify reproductive organ identities and to repress A function. HEN1 also shares AG's non-homeotic function in controlling floral determinacy. HEN1 may achieve these functions by regulating the expression of AG. hen1 single mutants exhibit pleiotropic phenotypes such as reduced organ size, altered rosette leaf shape and increased number of coflorescences, during most stages of development. Therefore, HEN1, like the A function gene AP2, plays multiple roles in plant development as well as acting in organ identity specification in the flower. HEN1 codes for a novel protein and is expressed throughout the plant.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics*
  • Cloning, Molecular
  • DNA-Binding Proteins*
  • Genes
  • Genes, Plant*
  • Homeodomain Proteins / genetics
  • MADS Domain Proteins
  • Meristem / genetics
  • Meristem / growth & development*
  • Molecular Sequence Data
  • Mutation
  • Nuclear Proteins / genetics
  • Phenotype
  • Plant Proteins / genetics
  • Plant Shoots / genetics
  • Plant Shoots / growth & development*
  • RNA, Messenger / isolation & purification
  • RNA, Plant / isolation & purification
  • RNA-Binding Proteins / genetics
  • Transcription Factors / genetics


  • AP1 protein, Arabidopsis
  • APETALA2 protein, Arabidopsis
  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • HEN1 protein, Arabidopsis
  • HUA1 protein, Arabidopsis
  • HUA2 protein, Arabidopsis
  • Homeodomain Proteins
  • MADS Domain Proteins
  • Nuclear Proteins
  • Plant Proteins
  • RNA, Messenger
  • RNA, Plant
  • RNA-Binding Proteins
  • Transcription Factors