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 m ay represent a cytosolic form of GPX, The structure of the HVGPH2 N-termina l 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 contras t, HVGPH3 mRNA accumulation showed a negative response to stress. Our data indicate that the barley genome bears a small gene family encoding GPX homo logues differing in their function and cellular localisation. (C) 1999 Fede ration of European Biochemical Societies.