RNA interference of the ecdysone receptor gene AgEcR in a wolfberry ‐ specialized strain of Aphis gossypii Glover affects its survival and fecundity and confers resistance in transgenic goji ( Lycium barbarum L .)

BACKGROUND: The ecdysone receptor (EcR) is essential for insect molting, metamorphosis and reproduction and has been validated as an effective RNA interference (RNAi) target in multiple insect species. However, its RNAi potential in the wolfberry - specialized strain of Aphis gossypii Glover remains unknown. We aimed to isolate the EcR ortholog from this aphid, screen for effective double - stranded RNA (dsRNA) fragments, and validate plant - mediated RNAi in transgenic goji. RESULTS: AgEcR transcripts were predominantly enriched in the body wall of fourth - instar nymphs. Among five in vitro synthesized AgEcR - dsRNA fragments individually incorporated into artificial diet for feeding assays, dsAgEcR2 exhibited the highest lethal efficacy, achieving >88.15% mortality and >96.06% target gene suppression by day 8. After a 3 - day feeding period, the silencing effect persisted for at least 12 days following transfer to susceptible hosts, during which adult longevity, reproductive period, and offspring production were significantly reduced. Transgenic goji lines expressing dsAgEcR2 under a phloem - specific promoter all caused substantial aphid mortality and reproductive impairment - a level that would severely suppress population growth under laboratory conditions. CONCLUSION: This study establishes AgEcR as a key target for controlling A. gossypii, with dsAgEcR2 targeting the D/E domain junction identified as the most potent silencing trigger. We also provide a complete pipeline from artificial diet-based screening to plant-mediated validation, demonstrating that goji - mediated RNAi effectively suppresses aphid survival and reproduction. This approach offers a practical and environmentally sound strategy for sustainable aphid management.