D3093: Developing an RNAi-based functional genomics tool in beet leafhopper for targeted vector control

Beet curly top virus (BCTV) is one of the most serious viral diseases and poses a significant threat to crops, particularly sugar beets, tomatoes, peppers, spinach, cucurbits, and beans. Transmitted by the beet leafhopper (Circulifer tenellus), the virus circulates through the insect's body without replication. Rapid acquisition of the virus by leafhoppers, coupled with their ability to retain and spread it for extended periods, necessitates innovative control strategies. This study centers on the development of an RNAi-based functional genomics tool in the beet leafhopper to address the challenge posed by BCTV.  We recently analyzed the transcriptome of BCTV-infected and healthy leafhoppers and identified a suite of genes that are differentially regulated by virus infection. Four candidate genes selected from the top 10 most differentially expressed genes (DEGs) were prioritized to pursue functionally in this project. These include genes encoding proteins that are involved in oogenesis (ovum development), insect performance (feeding, development, and defense), muscle contraction, and DNA repair. The methodology involves conducting RNA interference experiments in age-synchronized adult female leafhoppers, specifically 5-day-old adults. 80 nL of double-stranded RNA (dsRNA)  at a concentration of 500 ng/μl are injected, followed by a five-day feeding period on sugar beet plants. Quantitative Reverse transcription polymerase chain reaction (qRT-PCR) analysis assessed the reduction in gene expression. Initial results showed RNAi successfully silenced genes in beet leafhoppers, suggesting RNAi-based vector control potential. This represents the first evidence of RNAi in beet leafhopper and demonstrates the potential for translational research in vector and disease control.