BENZOTHIADIAZOLE, A NOVEL CLASS OF INDUCERS OF SYSTEMIC ACQUIRED-RESISTANCE, ACTIVATES GENE-EXPRESSION AND DISEASE RESISTANCE IN WHEAT

Systemic acquired resistance is an important component of the disease resistance repertoire of plants. In this study, a novel synthetic chem ical, benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH), was shown to induce acquired resistance in wheat. BTH protected wheat systemically against powdery mildew infection by affecting multiple s teps in the life cycle of the pathogen. The onset of resistance was ac companied by the induction of a number of newly described wheat chemic ally induced (WCl) genes, including genes encoding a lipoxygenase and a sulfur-rich protein. With respect to both timing and effectiveness, a tight correlation existed between the onset of resistance and the in duction of the WCl genes. Compared with other plant activators, such a s 2,6-dichloroisonicotinic acid and salicylic acid, BTH was the most p otent inducer of both resistance and gene induction. BTH is being deve loped commercially as a novel type of plant protection compound that w orks by inducing the plant's inherent disease resistance mechanisms.