Localization of light-inducible and tissue-specific regions of the spinach ribulose bisphosphate carboxylase/oxygenase (rubisco) activase promoter in transgenic tobacco plants

Plant Mol Biol. 1993 Dec;23(6):1129-38. doi: 10.1007/BF00042347.

Abstract

Deletions in the spinach rubisco activase (Rca) promoter in transgenic tobacco were analyzed to define the regions necessary for conferring light-inducible and tissue-specific expression. Transgenic plants were constructed with Bal 31 deletions of the Rca promoter fused to the coding region of the bacterial reporter gene beta-glucuronidase (GUS). Analysis of the Rca deletion mutants localized the region conferring normal expression downstream from -294 relative to the Rca transcription start site. A second set of transgenic plants containing the cauliflower mosaic virus (CaMV) 35S enhancer fused to the 3' end of the Rca/GUS constructs demonstrated the presence of a light-responsive element between -150 and -78 active in leaves. Regions 10 bp long within the light-responsive region, which included putative G box and GT elements, were removed by recombinant polymerase chain reaction. Deletion of the G box element resulted in a loss of gene expression in the leaves of transgenic tobacco, while deletion of the GT motif caused a 10-100-fold increase in expression in roots. However, site-directed mutagenesis of the GT motif resulted in expression patterns identical to the normal promoter. These experiments demonstrated that light-inducible and tissue-specific expression of the Rca promoter involves multiple cis elements proximal to the transcription start site, and that interactions between these elements are essential for regulating expression.

MeSH terms

  • Gene Expression Regulation*
  • Genes, Plant
  • Light
  • Plant Proteins / genetics*
  • Plants, Genetically Modified
  • Plants, Toxic
  • Promoter Regions, Genetic*
  • RNA, Messenger / genetics
  • Ribulose-Bisphosphate Carboxylase / genetics*
  • Ribulose-Bisphosphate Carboxylase / metabolism
  • Sequence Deletion
  • Structure-Activity Relationship
  • Tobacco / genetics
  • Transcription, Genetic
  • Vegetables / genetics*

Substances

  • Plant Proteins
  • RNA, Messenger
  • rca protein, plant
  • Ribulose-Bisphosphate Carboxylase