Discovery of target genes for insecticidal RNAi against fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae).

• Grant number: 19/19808-4
• Support type: Scholarships abroad - Research
• Effective date (Start): January 01, 2020
• Effective date (End): August 31, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal researcher: Sergio Antonio de Bortoli
• Grantee: Sergio Antonio de Bortoli
• Host: Juan Luis Jurat-Fuentes
• Home Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Research place: University of Tennessee (UT), United States

Abstract

The research will be performed using transcriptome data of Spodoptera frugiperda (Lep.: Noctuidae), fall armyworm. We will find homologues for ten genes that have been reported in the literature to be effective for insecticidal gene silencing. Regions of all target genes (~200 bp) will be selected based on the literature and cloned into a plasmid with terminal T7 promoter regions at both ends. In vitro transcription will yield double stranded RNA (dsRNA) targeting each gene. Since dsRNA displays low activity by feeding in fall armyworm, injection will be used to test for insecticidal activity of the ten prepared dsRNAs. The dsRNAs will be injected in 3rd instar larvae, and mortality recorded until pupation and adult emergence. The two most active dsRNAs will be selected for feeding bioassays. Bioassays will be performed against fall armyworm larvae using surface contamination of diet with the two most active dsRNAs from the injection assays. dsRNA uptake will be enhanced to increase toxicity using enhancers such as liposomes and nanoparticles encapsulating the dsRNA.