The Bacteria-Derived dsRNA Was Used for Spray-Induced Gene Silencing for Rice False Smut Control

False smut caused by Ustilaginoidea virens is one of the most destructive diseases in rice. The disease is primarily controlled with fungicides, leading to the development of fungicide resistance. Although spray-induced gene silencing (SIGS) has been utilized for disease management, it has not been applied to control rice false smut. In this study, we introduce a novel approach involving the in vivo synthesis and exogenous application of double-stranded RNA (dsRNA) to manage rice false smut disease. The UvCYP51, UvBI-1, and UvbZIP11 genes were selected as target genes and highly efficient fragments for gene silencing were identified through screening of silencing transformants. Although direct dsRNA uptake by U. virens was not observed, in vivo synthesis and application of dsRNA to rice effectively reduced the expression of target genes. Treatment with dsRNA targeting the genes resulted in a decrease in smut balls, providing a promising disease management strategy against rice false smut.