Strong seed-specific protein expression from the Vigna radiata storage protein 8SGα promoter in transgenic Arabidopsis seeds

J Biotechnol. 2014 Mar 20;174:49-56. doi: 10.1016/j.jbiotec.2014.01.027. Epub 2014 Feb 3.

Abstract

Vigna radiata (mung bean) is an important crop plant and is a major protein source in developing countries. Mung bean 8S globulins constitute nearly 90% of total seed storage protein and consist of three subunits designated as 8SGα, 8SGα' and 8SGβ. The 5'-flanking sequences of 8SGα' has been reported to confer high expression in transgenic Arabidopsis seeds. In this study, a 472-bp 5'-flanking sequence of 8SGα was identified by genome walking. Computational analysis subsequently revealed the presence of numerous putative seed-specific cis-elements within. The 8SGα promoter was then fused to the gene encoding β-glucuronidase (GUS) to create a reporter construct for Arabidopsis thaliana transformation. The spatial and temporal expression of 8SGα∷GUS, as investigated using GUS histochemical assays, showed GUS expression exclusively in transgenic Arabidopsis seeds. Quantitative GUS assays revealed that the 8SGα promoter showed 2- to 4-fold higher activity than the Cauliflower Mosaic Virus (CaMV) 35S promoter. This study has identified a seed-specific promoter of high promoter strength, which is potentially useful for directing foreign protein expression in seed bioreactors.

Keywords: Genome-walking; Promoter; Seed-specific; Transgenic Arabidopsis; Vigna radiata; β-Glucuronidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Base Sequence
  • Chromosome Walking
  • Fabaceae / genetics
  • Gene Expression Regulation, Plant
  • Genes, Plant*
  • Genome, Plant
  • Glucuronidase / genetics
  • Glucuronidase / metabolism
  • Molecular Sequence Data
  • Plants, Genetically Modified / metabolism*
  • Promoter Regions, Genetic
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Seed Storage Proteins / genetics*
  • Seed Storage Proteins / metabolism
  • Seeds / genetics
  • Seeds / metabolism*
  • Sequence Alignment

Substances

  • Recombinant Fusion Proteins
  • Seed Storage Proteins
  • Glucuronidase