Two Cis-Acting Regulatory Elements Are Involved in the Sucrose-Inducible Expression of the Sporamin Gene Promoter From Sweet Potato in Transgenic Tobacco

Mol Genet Genomics. 2005 Feb;272(6):690-9. doi: 10.1007/s00438-004-1100-y. Epub 2005 Jan 15.

Abstract

In this study, we generated transgenic tobacco plants that express the beta-glucuronidase (GUS) gene under the control of the 305-bp 5'-upstream region of a gene coding for sporamin A of sweet potato. Expression of GUS in excised tobacco leaves was induced by sucrose, mimicking the sugar-inducible expression of the endogenous sporamin genes in sweet potato. Deletion of the sequences extending from position -305 (relative to the transcription start site) to -283 and from -146 to -87 resulted in an approximately 40-fold enhancement in GUS reporter expression. Furthermore, the sequence from -282 to -165 conferred sucrose-inducibility on the -89 core promoter of the Cauliflower Mosaic Virus 35S RNA gene. Analysis of internal deletions, linker scanning and the introduction of base substitutions in the sequence between positions -282 and -165 indicated that sucrose-responsiveness conferred by this region was dependent on the presence of two cis-acting elements, termed CMSREs (carbohydrate metabolite signal responsive elements) 1 and 2, which are separated by a spacer. A sequence similar or identical to the core of CMSRE-1 (TGGACGG) is also present in the promoters of several other sugar-inducible genes, and sequences encopassing the TGGACGG-related motifs from two of these could functionally replace the CMSRE-1 in the truncated sporamin A promoter. These results suggest that the TGGACGG element plays an important role in the sucrose-inducible expression of a group of plant genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Caulimovirus / genetics
  • Gene Expression / drug effects
  • Gene Expression Regulation, Plant*
  • Genes, Plant
  • Glucuronidase / genetics
  • Glucuronidase / metabolism
  • Molecular Sequence Data
  • Plant Proteins / genetics*
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism*
  • Promoter Regions, Genetic / genetics
  • Response Elements / genetics*
  • Sequence Deletion
  • Sucrose / pharmacology*
  • Tobacco / genetics*
  • Tobacco / metabolism

Substances

  • Plant Proteins
  • sporamin A protein, Ipomoea batatas
  • Sucrose
  • Glucuronidase