Study Finds Key Defense Strategy in Rice Against Blast Disease

In a study conducted by researchers from Yunnan Agricultural University and partners, they found that overexpressing a fungal effector gene, PWL2, in rice can boost the plant's resistance against blast disease caused by Magnaporthe oryzae. When introduced into rice, PWL2 helped strengthen the plant's immune response and revealed a previously unknown defense mechanism in rice.

The study showed that transgenic rice lines expressing PWL2 developed smaller lesions and lower disease levels compared to non-transgenic plants. During the early stages of infection, salicylic acid (SA), a hormone that triggers plant defense, activated key immune genes, but they were found to become less active as the infection progressed. The study confirmed that SA plays a crucial role in helping rice resist M. oryzae.

The researchers concluded that rice plants use a temporal decoupling of SA-dependent and RNAi-mediated defenses against rice blast disease. Early resistance is controlled by SA-dependent defenses, while defense during the late stage relies on siRNA-mediated defense dominance. The study offers new insight into how rice uses multiple defense systems to fight fungal infections and could help in developing disease-resistant crop varieties in the future.

For more information, read the study from MPDI.