Benzothiadiazole (BTH) is a well known inducer of systemic acquired resistance in several plants. The ability of this chemical to induce resistance was studied in Brassica juncea to combat Alternaria blight. Benzothiadiazole (10 and 50ppm) treated seeds of B. juncea showed an elevation in the activity of defense related enzymes viz, peroxidase, phenylalanine ammonia lyase and superoxide dismutase in the hypocotyls and cotyledonary leaves sampled from the germinated seedlings. Corresponding change in the phenolic content was also observed. Out of the two concentrations tried, 50ppm of benzothiadiazole showed maximum increase in defense enzymes and phenolics. In addition to this, treatment with both 10 and 50ppm of benzothiadiazole showed increase in number of phenolics bands as compared to water treated control. These results suggest that BTH promotes resistance in B. juncea by increasing the level of defense related compounds and may act as a useful tool to induce resistance in mustard.
Benzothiadiazole, Brassica juncea, induced resistance, systemic acquired resistance, defense enzymes
