Multiple interactions amongst floral homeotic MADS box proteins

EMBO J. 1996 Aug 15;15(16):4330-43.


Most known floral homeotic genes belong to the MADS box family and their products act in combination to specify floral organ identity by an unknown mechanism. We have used a yeast two-hybrid system to investigate the network of interactions between the Antirrhinum organ identity gene products. Selective heterodimerization is observed between MADS box factors. Exclusive interactions are detected between two factors, DEFICIENS (DEF) and GLOBOSA (GLO), previously known to heterodimerize and control development of petals and stamens. In contrast, a third factor, PLENA (PLE), which is required for reproductive organ development, can interact with the products of MADS box genes expressed at early, intermediate and late stages. We also demonstrate that heterodimerization of DEF and GLO requires the K box, a domain not found in non-plant MADS box factors, indicating that the plant MADS box factors may have different criteria for interaction. The association of PLENA and the temporally intermediate MADS box factors suggests that part of their function in mediating between the meristem and organ identity genes is accomplished through direct interaction. These data reveal an unexpectedly complex network of interactions between the factors controlling flower development and have implications for the determination of organ identity.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • DEFICIENS Protein
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Dimerization
  • Gene Expression Regulation, Developmental*
  • Gene Expression Regulation, Plant*
  • Genes, Homeobox
  • Genes, Plant
  • Homeodomain Proteins / chemistry
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • MADS Domain Proteins
  • Macromolecular Substances
  • Molecular Sequence Data
  • Plant Development*
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants / genetics
  • Regulatory Sequences, Nucleic Acid*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • DEFICIENS Protein
  • DNA-Binding Proteins
  • GLOBOSA protein, plant
  • Homeodomain Proteins
  • MADS Domain Proteins
  • Macromolecular Substances
  • PLE protein, Antirrhinum majus
  • Plant Proteins
  • Transcription Factors
  • SQUA protein, Antirrhinum majus

Associated data

  • GENBANK/X95467
  • GENBANK/X95468
  • GENBANK/X95469