Mutation of either G box or I box sequences profoundly affects expression from the Arabidopsis rbcS-1A promoter

EMBO J. 1990 Jun;9(6):1717-26.

Abstract

A deletion analysis of the Arabidopsis thaliana rbcS-1A promoter defined a 196 bp region (-320 to -125) sufficient to confer light-regulated expression on a heterologous Arabidopsis alcohol dehydrogenase (Adh) reporter gene in transgenic Nicotiana tabacum (tobacco) leaves. This region, which contains DNA sequences I, G and GT boxes, with homology to other ribulose-1,5-bisphosphate carboxylase small subunit (RBCS) gene promoter sequences, directed expression independent of orientation and relative position in the Adh promoter. Site-specific mutagenesis of these conserved sequences and subsequent expression analysis in transgenic tobacco showed that both G box and I box mutations in the context of the full (-1700 to +21) rbcS-1A promoter substantially reduced the expression of Adh and beta-glucuronidase (GUS) reporter genes. The G box has previously been shown to specifically bind in vitro a factor isolated from nuclear extracts of tomato and Arabidopsis. This factor (GBF) is distinct from the factor GT-1 which binds to adjacent GT boxes in the pea rbcS-3A promoter. Multiple mutations in putative Arabidopsis rbcS-1A promoter GT boxes had no pronounced affect on expression, possibly due to a redundancy of these sites. Experiments in which rbcS-1A promoter fragments were fused to truncated 35S CaMV (cauliflower mosaic virus) promoter--GUS reporter constructs showed that cis-acting CaMV promoter elements could partially restore expression to G-box-mutated rbcS-1A sequences.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alcohol Dehydrogenase / genetics
  • Base Sequence
  • DNA / genetics*
  • Drug Synergism
  • Glucuronidase / genetics
  • Light
  • Molecular Sequence Data
  • Mosaic Viruses / genetics
  • Mutation
  • Plants / genetics*
  • Promoter Regions, Genetic*
  • Ribulose-Bisphosphate Carboxylase / genetics*

Substances

  • DNA
  • Alcohol Dehydrogenase
  • Glucuronidase
  • Ribulose-Bisphosphate Carboxylase