{Reference Type}: Journal Article
{Title}: Ex vivo delivery of dsRNA targeting ryanodine receptors for control of Tuta absoluta.
{Author}: Askew WT;Edwards MG;Gatehouse AMR;
{Journal}: Pest Manag Sci
{Volume}: 0
{Issue}: 0
{Year}: 2024 Aug 16
{Factor}: 4.462
{DOI}: 10.1002/ps.8368
{Abstract}: <B>BACKGROUND: </B>RNA interference (RNAi) is an endogenous eukaryote viral defence mechanism representing a unique form of post-transcriptional gene silencing. Owing to its high specificity, this technology is being developed for use in dsRNA-based biopesticides for control of pest insects. Whilst many lepidopteran species are recalcitrant to RNAi, Tuta absoluta, a polyphagous insect responsible for extensive crop damage, is sensitive. Ryanodine receptors (RyRs) are intracellular calcium channels regulating calcium ion (Ca2+) release. The chemical pesticide class of diamides functions agonistically against lepidopteran RyR, resulting in uncontrolled Ca2+ release, feeding cessation and death. Resistance to diamides has emerged in T. absoluta, derived from RyR point mutations.<BR><B>RESULTS: </B>RNAi was used to target RyR transcripts of T. absoluta. Data presented here demonstrate the systemic use of exogenous T. absoluta RyR-specific (TaRy) dsRNA in tomato plants (Solanum lycopersicum) to significantly downregulate expression of the target gene, resulting in significant insect mortality and reduced leaf damage. Using a leaflet delivery system, daily dosing of 3 μg TaRy dsRNA for 72 h resulted in 50% downregulation of the target gene and 50% reduction in tomato leaf damage. Corrected larval mortality and adult emergence were reduced by 38% and 33%, respectively. TaRy dsRNA demonstrated stability in tomato leaves ≤72 h after dosing.<BR><B>CONCLUSIONS: </B>This work identifies TaRy as a promising target for RNAi control of this widespread crop pest. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.