Characterization of the Antirrhinum floral homeotic MADS-box gene deficiens: evidence for DNA binding and autoregulation of its persistent expression throughout flower development

EMBO J. 1992 Jan;11(1):251-63.


We have determined the structure of the floral homeotic deficiens (defA) gene whose mutants display sepaloid petals and carpelloid stamens, and have analysed its spatial and temporal expression pattern. In addition, several mutant alleles (morphoalleles) were studied. The results of these analyses define three functional domains of the DEF A protein and identify in the deficiens promoter a possible cis-acting binding site for a transcription factor which specifically upregulates expression of deficiens in petals and stamens. In vitro DNA binding studies show that DEF A binds to specific DNA motifs as a heterodimer, together with the protein product of the floral homeotic globosa gene, thus demonstrating that the protein encoded by deficiens is a DNA binding protein. Furthermore, Northern analysis of a temperature sensitive allele at permissive and non-permissive temperatures provides evidence for autoregulation of the persistent expression of deficiens throughout flower development. A possible mechanism of autoregulation is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • Crosses, Genetic
  • Gene Expression Regulation*
  • Genes, Homeobox*
  • Heterozygote
  • Models, Genetic
  • Molecular Sequence Data
  • Morphogenesis / genetics*
  • Mutation
  • Plants / embryology
  • Plants / genetics*
  • RNA Precursors
  • Regulatory Sequences, Nucleic Acid / genetics
  • Time Factors
  • Tissue Distribution
  • Transcription Factors / genetics
  • Up-Regulation


  • RNA Precursors
  • Transcription Factors

Associated data

  • GENBANK/X62810
  • GENBANK/X62840
  • GENBANK/X62841
  • GENBANK/X66290
  • GENBANK/X66291
  • GENBANK/X66292
  • GENBANK/X66293
  • GENBANK/X66294
  • GENBANK/X67725
  • GENBANK/X67726