Different patterns of host genes are induced in rice by Pseudomonas syringae, a biological inducer of resistance, and the chemical inducer benzothiadiazole (BTH)

Rice seedlings treated with the synthetic compound benzo(1,2,3)thiadiazole- 7-carbothioic acid S-methyl ester (BTH) acquired resistance to subsequent a ttack by the rice blast fungus Magnaporthe grisea (Hebert) Barr. BTH (trade name Bion (TM)) has been released to the market as a plant protecting agen t for rice. Here, we analysed the pattern of expressed genes in rice plants treated with BTH, and compared this pattern with those induced by the form erly discovered resistance inducer 2,6-dichloroisonicotinic acid (INA) and by Pseudomonas syringae pv. syringae, a non-host pathogen inducing a hypers ensitive response. Both INA and BTH induced similar patterns of genes, sugg esting that these compounds are functional analogues. In contrast, the patt erns induced by the chemical inducers and by P. syringae were clearly dissi milar.