Induction of resistance to Xanthomonas oryzae pv. oryzae in rice by benzothiadiazole (BTH)

Systematic acquired resistance induced by benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH) in rice against bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae was studied. Rice plants (IR 50) pre-treated with BTH showed resistance to a challenge infection with Xanthomonas oryzae pv. oryzae. About 50% reduction in disease intensity was observed in plants treated with BTH at 100 μg a.i./ml. Immunoblot analysis using barley chitinase antiserum revealed the induction of a 35 kDa chitinase in rice in response to treatment with BTH. The results indicate that the BLB resistance can be induced even in genetically susceptible cultivar through application of BTH.