Promoter analysis of the auxin-regulated tobacco glutathione S-transferase genes Nt103-1 and Nt103-35

Plant Mol Biol. 1995 Nov;29(3):413-29. doi: 10.1007/BF00020974.

Abstract

We have analysed the promoter regions of two closely related auxin-regulated glutathione S-transferase genes. All active deletion constructs tested showed expression of the reporter gene beta-glucuronidase (gusA) in root tips of young seedlings and newly developing lateral roots. Auxin treatment greatly enhanced the level of expression. The Nt103-1 promoter region -370/-276 was found to be necessary, at least as a quantitative element to confer auxin-responsiveness to a reporter gene, and sequences responsible for the auxin-responsiveness must be located downstream of -370. The region -651/-370 contains sequence information necessary for uninduced expression. The Nt103-35 promoter manifested its auxin-responsiveness within the -504/-310 region. Electrophoretic mobility shift analysis, using nuclear extracts from tobacco leaves and suspension cells, identified a factor binding to a sequence (ap103, TGAGTCT) at position -560 of the Nt103-1 promoter, which shows homology to the mammalian AP-1 site. A second factor was found to bind a sequence (as103, ATAGCTAAGTGCTTACG) with homology to the CaMV 35S promoter as-1 element. The as103 element is present in both promoters and positioned around -360, so within the region determined to be indispensable for the response to auxin. A third factor was found binding to the -276/-190 region of both promoters. Combined, these data point to the relevance of a 90 bp region for auxin-induced activity of both tobacco genes. The ASF-1 like factor binding to the as103 element within this region might be involved in mediating the auxin response.

Publication types

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

MeSH terms

  • Base Sequence
  • Gene Expression Regulation, Enzymologic*
  • Gene Expression Regulation, Plant*
  • Genes, Plant*
  • Genetic Vectors
  • Glucuronidase / biosynthesis
  • Glutathione Transferase / biosynthesis
  • Glutathione Transferase / genetics*
  • Indoleacetic Acids / physiology*
  • Molecular Sequence Data
  • Promoter Regions, Genetic*
  • Recombinant Proteins / biosynthesis
  • Restriction Mapping
  • Rhizobium
  • Sequence Homology, Nucleic Acid
  • TATA Box

Substances

  • Indoleacetic Acids
  • Recombinant Proteins
  • Glutathione Transferase
  • Glucuronidase