HvGER4 and HvGER5 possess SOD activity that is destroyed by mutation of one conserved His residue. A, SOD in-gel assay with protein extracts from one selected Arabidopsis T0 line expressing either wild-type (wt) or mutant (M) GLP. H, Protein extract from Bgh-attacked barley leaves; A, protein extract from Arabidopsis wild-type leaves; SOD, commercial SOD from horseradish (Sigma-Aldrich). B, Same protein extracts as shown in A were subjected to western blotting.