Characterization and Expression Analysis of a Glutathione Reductase Gene from Antarctic Moss Pohlia nutans

Glutathione reductase (GR) is a flavoprotein oxidoreductase and plays an important role in response to oxidative stresses in plants. A cDNA-encoding cytosolic GR [GenBank accession number GACA01029426, designated as Pohlia nutans glutathione reductase gene (PnGR)] was successfully cloned from Antarctic moss P. nutans. The full-length PnGR cDNA has 1,654 bp nucleotides with an open reading frame of 1,494 bp, encoding 497 amino acid residues. The deduced amino acid sequence of PnGR had 87.0 % identity with GR in Physcomitrella patens subsp. patens. The phylogenetic analysis showed that PnGR is clustered together with known cytosolic GR in other plants. In addition, the subcellular localization analysis by observing the transient expression of PnGR-green fluorescent protein fusion protein in Arabidopsis thaliana mesophyll protoplasts also revealed PnGR targeting to cytosol in plant cells. The expression patterns of PnGR under different abiotic stresses were determined by real-time PCR. Compared to the normal condition, the maximal mRNA accumulation of PnGR increased 3.82-fold at 4 A degrees C, 2.92-fold at 10 A degrees C, 4.14-fold with 200 mM NaCl, and 3.17-fold with drought stress, respectively. Together, our results suggested that the inducible PnGR might play an important role in Antarctic moss P. nutans acclimatizing to polar environment.