Abstract
Systemic acquired resistance (SAR), one of plant defense systems, is induced by pathogen infection through salicylic acid (SA) accumulation. SAR has been practically utilized in rice fields by exploiting the plant activators capable of inducing of SAR. Benzisothiazole (BIT) is a plant activator that induces SAR in rice, tobacco and arabidopsis. In Arabidopsis, environmental stress responses via abscisic acid (ABA) suppresses the SAR induction by BIT. Because of the economical importance of the stable induction of SAR, we have investigated the effects of environmental stresses on SAR in rice. BIT induced the resistance against rice blast fungus, however, which was suppressed by environmental stress. ABA treatment reduced the BIT-induced disease resistance. These data indicated that environmental stress response suppresses SAR development in rice.
