abstract
In this study, the effect of light on the protection of rice against blast caused by Magnaporthe oryzae was
investigated. When rice inoculated with M. oryzae was kept in the dark for 24 h and then exposed to
various light conditions, the formation of a susceptible blast lesion was significantly inhibited under red
light compared with natural or white light. Furthermore, there was greater formation of necrotic spots
under red light compared to natural and white lights. The activity of phenylalanine ammonia-lyase (PAL)
increased significantly after inoculation with M. oryzae spores in red light-treated rice, as compared with
natural or white light-treated rice. This activity reached a maximum at 48 h after inoculation.