Glutathione reductase a unique enzyme: molecular cloning, expression and biochemical characterization from the stress adapted C4 plant, Pennisetum glaucum (L.) R. Br

Mol Biol Rep. 2015 May;42(5):947-62. doi: 10.1007/s11033-014-3832-z. Epub 2014 Nov 18.

Abstract

The generation of excess reactive oxygen species (ROS) is one of the most common consequences of abiotic stress on plants. Glutathione reductase (GR, E.C. 1.6.4.2) and allied enzymes of the ascorbate-glutathione cycle play a crucial role to maintain the homeostatic redox balance in the cellular environment. GR plays an essential role in upholding the reduced glutathione pool under stress conditions. In the present study, a full-length GR cDNA and corresponding genomic clone was isolated from Pennisetum glaucum (L.) R. Br. The PgGR cDNA, encodes a 497-amino acid peptide with an estimated molecular mass of ~53.5 kDa. The PgGR peptide exhibits 54-89% sequence homology with GR from other plants and is cytoplasmic in nature. The PgGR enzyme was purified to near homogeneity, the recombinant protein being relatively thermostable and displaying activity in a broad range of temperature, pH and substrate concentrations. The PgGR transcript level was differentially regulated by heat, cold, salinity and methyl viologen-induced oxidative stress. The heterologously expressed PgGR protein in E. coli showed an improved protection against metal- and methyl viologen-induced oxidative stress. Our overall finding underscores the role of PgGR gene that responds to multiple abiotic stresses and provides stress tolerance in the experimental model (E. coli) which can be potentially used for the improvement of crops under abiotic stress conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Genes, Plant
  • Glutathione Reductase / chemistry
  • Glutathione Reductase / genetics*
  • Glutathione Reductase / isolation & purification
  • Glutathione Reductase / metabolism
  • Molecular Sequence Data
  • Oxidative Stress / physiology*
  • Pennisetum / enzymology*
  • Pennisetum / genetics
  • Phylogeny
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism
  • Protein Conformation

Substances

  • Plant Proteins
  • Glutathione Reductase