An fmt mutant has elevated sensitivity to hydrogen peroxide, paraquat and MG stress. (a) Representative photograph (from at least six replicates) of disc diffusion assays with WT (CU1065), an fmt mutant (HB21006) and an fmt Pspac(hy)-fmt complemented strain (HB21016) on LB plates. The discs were spotted with hydrogen peroxide (H2O2, 2.4 µmol), paraquat (PQ, 2.5 µmol) or MG (27.5 µmol) as indicated. (b) Sensitivity of WT and various mutant strains to hydrogen peroxide. The results are expressed as the diameter of the inhibition zone (mm) minus the diameter of the filter paper disc (6.5 mm). The mean±se from at least three biological replicates is reported.