Deficiens, a homeotic gene involved in the control of flower morphogenesis in Antirrhinum majus: the protein shows homology to transcription factors

EMBO J. 1990 Mar;9(3):605-13.


Deficiens (defA+) is a homeotic gene involved in the genetic control of Antirrhinum majus flower development. Mutation of this gene (defA-1) causes homeotic transformation of petals into sepals and of stamina into carpels in flowers displaying the 'globifera' phenotype, as shown by cross sections and scanning electronmicroscopy of developing flowers. A cDNA derived from the wild type defA+ gene has been cloned by differential screening of a subtracted 'flower specific' cDNA library. The identity of this cDNA with the defA+ gene product has been confirmed by utilizing the somatic and germinal instability of defA-1 mutants. According to Northern blot analyses the defA+ gene is expressed in flowers but not in leaves, and its expression is nearly constant during all stages of flower development. The 1.1 kb long mRNA has a 681 bp long open reading frame that can code for a putative protein of 227 amino acids (mol. wt 26.2 kd). At its N-terminus the DEF A protein reveals homology to a conserved domain of the regulatory proteins SRF (activating c-fos) in mammals and GRM/PRTF (regulating mating type) in yeast. We discuss the structure and the possible function of the DEF A protein in the control of floral organogenesis.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • DEFICIENS Protein
  • DNA / genetics
  • Gene Library
  • Genes, Homeobox*
  • Homeodomain Proteins / genetics*
  • Microscopy, Electron, Scanning
  • Molecular Sequence Data
  • Morphogenesis
  • Mutation
  • Phosphorylation
  • Plant Development
  • Plant Proteins / genetics*
  • Plants / genetics*
  • Plants / ultrastructure
  • Protein Biosynthesis
  • Sequence Homology, Nucleic Acid
  • Transcription Factors / genetics*


  • DEFICIENS Protein
  • Homeodomain Proteins
  • Plant Proteins
  • Transcription Factors
  • DNA