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

False smut caused by <i>Ustilaginoidea virens</i> 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 <i>in vivo</i> synthesis and exogenous application of double-stranded RNA (dsRNA) to manage rice false smut disease. The <i>UvCYP51</i>, <i>UvBI-1</i>, and <i>UvbZIP11</i> 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 <i>U. virens</i> was not observed, <i>in vivo</i> 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.