ACGT-containing abscisic acid response element (ABRE) and coupling element 3 (CE3) are functionally equivalent

Plant J. 1999 Sep;19(6):679-89. doi: 10.1046/j.1365-313x.1999.00565.x.


ACGT-containing ABA response elements (ABREs) have been functionally identified in the promoters of various genes. In addition, single copies of ABRE have been found to require a cis-acting, coupling element to achieve ABA induction. A coupling element 3 (CE3) sequence, originally identified as such in the barley HVA1 promoter, is found approximately 30 bp downstream of motif A (ACGT-containing ABRE) in the promoter of the Osem gene. The relationship between these two elements was further defined by linker-scan analyses of a 55 bp fragment of the Osem promoter, which is sufficient for ABA-responsiveness and VP1 activation. The analyses revealed that both motif A and CE3 sequence were required not only for ABA-responsiveness but also for VP1 activation. Since the sequences of motif A and CE3 were found to be similar, motif-exchange experiments were carried out. The experiments demonstrated that motif A and CE3 were interchangeable by each other with respect to both ABA and VP1 regulation. In addition, both sequences were shown to be recognized by a VP1-interacting, ABA-responsive bZIP factor TRAB1. These results indicate that ACGT-containing ABREs and CE3 are functionally equivalent cis-acting elements. Furthermore, TRAB1 was shown to bind two other non-ACGT ABREs. Based on these results, all these ABREs including CE3 are proposed to be categorized into a single class of cis-acting elements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology*
  • Base Sequence
  • Basic-Leucine Zipper Transcription Factors
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Plant*
  • Molecular Sequence Data
  • Plant Proteins / genetics*
  • Protein Binding
  • Response Elements*
  • Trans-Activators
  • Transcription Factors / metabolism*


  • Basic-Leucine Zipper Transcription Factors
  • DNA-Binding Proteins
  • Osem protein, Oryza sativa
  • Plant Proteins
  • TRAB1 protein, plant
  • Trans-Activators
  • Transcription Factors
  • Abscisic Acid