ELECTROPHORETIC ANALYSIS OF TOTAL AND MEMBRANE-PROTEINS OF XANTHOMONAS-CAMPESTRIS PATHOVARS, THE CAUSAL AGENTS OF THE LEAF STREAK OF CEREALS AND GRASSES IN IRAN

Forty-five Iranian isolates of Xanthomonas campestris obtained from wh eat, barley and grasses were compared with reference strains using pol yacrylamide gel electrophoresis (PAGE) of the whole-cell and membrane proteins. The PAGE profiles of the whole-cell and membrane proteins of the Iranian isolates obtained from barley, with the exception of IBLS 11 and IBLS 12, were identical and clearly distinguishable from those of the other isolates. The barley group isolates, which were pathogen ic only to barley, were similar to UPB 458 (NCPPB 2389), the reference strain of pathovar hordei. The isolates obtained from wheat and grass es, as well as IBLS 11 and IBLS 12, which can infect wheat, barley and some wild grasses, had similar banding patterns; only IBLS 40 isolate d from Hordeum sp. displayed the same profile as the barley group. Ref erence strains UPB 443 (NCPPB 2821) and UPB 513, which correspond to p athovars undulosa and translucens, respectively, were related to the w heat group. IBLS45, isolated from Bromus sp., had a banding pattern th at differed from those observed for strains of the barley and wheat gr oups. The results suggest that this method can be useful for discrimin ating different pathovars of X. campestris attacking cereals and grass es, and sodium dodecyl sulphate (SDS)-PAGE of membrane proteins was no t more sensitive than SDS-PAGE of total proteins for differentiating t he isolates.