Isolation of jasmonate-induced sesquiterpene synthase of rice: Product of which has an antifungal activity against Magnaporthe oryzae

Rice is one of the most important crops worldwide, and it is a model for molecular studies of monocotyledonous species, particularly for understanding the molecular mechanisms of plant disease resistance. Jasmonic acid (JA) is an important plant hormone involved in rice–pathogen interactions. In addition, JA-induced volatiles are known to be involved in the rice defense system regulated by JA signaling. In this study, we isolated a JA-induced terpene synthase from rice, and found that it produces two sesquiterpenes; β-elemene and β-bisabolene. Furthermore, β-elemene exhibited significant antifungal activity against Magnaporthe oryzae; however it did not exhibited any antibacterial activity against Xanthomonas oryzae pv. oryzae. JA-induced accumulation of β-elemene was regulated by OsJAZ8, a rice jasmonate ZIM-domain (JAZ) protein that is involved in the JA signaling pathway, suggesting that β-elemene plays an important role in JA-induced resistance, and that it functions as an antifungal compound in rice.