XVI International Botanical Congess

It was known that methionine(Met)-treatment reduced rice blast disease. But there is less information on a defense mechanism by Met. We reported here that Met elicited the production of rice phytoalexins, sakuranetin and momilactone A. Droplets of a test solution were applied to press injured spots on rice leaves. After incubation, phytoalexins extracted with 70% MeOH and quantitated with LC/MS/MS. Met treatment induced the accumulation of sakuranetin and momilactone A. Ethylene is understood to play an important role in activating self-defencive systems. The Met induced phytoalexin production was reduced by ethylene biosynthesis inhibitor. This result suggests that ethylene might play an important role for phytoalexin production in Met treate.