A gene family encoding glutathione peroxidase homologues in Hordeum vulgare (barley).

We have isolated and characterised three barley cDNAs encoding glutathione peroxidase (GPX) homologues, designated HVGPH1, HVGPH2 and HVGPH3. HVGPH1 may represent a cytosolic form of GPX. The structure of the HVGPH2 N-terminal domain is typical for a plastid transit peptide. A potential peroxisomal targeting sequence occurs near the N-terminus of HVGPH3. Transcript levels of HVGPH1 and HVGPH2 were increased in leaves undergoing stress. In contrast, HVGPH3 mRNA accumulation showed a negative response to stress. Our data indicate that the barley genome bears a small gene family encoding GPX homologues differing in their function and cellular localisation.