First Evidence of Bud Feeding-Induced RNAi in a Crop Pest via Exogenous Application of dsRNA

Jonathan Willow*, Liina Soonvald, Silva Sulg, Riina Kaasik, Ana Isabel Silva, Clauvis Nji Tizi Taning, Olivier Christiaens, Guy Smagghe, Eve Veromann*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Web of Science)

Abstract

Simple Summary

An ecologically sustainable strategy for managing the pollen beetle Brassicogethes aeneus, a key pest of oilseed rape (Brassica napus) in Europe, is greatly needed. Gene silencing via RNA interference, through sprayed applications of target-specific double-stranded RNA, represents a potential alternative to conventional insecticides. We used dsRNA designed to target a vital gene in this pollen beetle species and allowed the beetles to feed on dsRNA-coated oilseed rape buds. We observed a significant silencing of the target gene; and this was followed by a significant, albeit delayed, reduction in pollen beetle survival rate. Further experiments are necessary in order to better understand the potential for developing a dsRNA-spray approach to pollen beetle management.

Spray-induced gene silencing (SIGS) is a potential strategy for agricultural pest management, whereby nucleotide sequence-specific double-stranded RNA (dsRNA) can be sprayed onto a crop; the desired effect being a consumption of dsRNA by the target pest, and subsequent gene silencing-induced mortality. Nucleotide sequence-specificity is the basis for dsRNA's perceived biosafety. A biosafe approach to pollen beetle (Brassicogethes aeneus) management in oilseed rape (Brassica napus) agroecosystems is needed. We examined the potential for SIGS in B. aeneus, via bud feeding, a field-relevant dsRNA exposure route. Oilseed rape buds were uniformly treated with dsRNA designed to target alpha COP in B. aeneus. Our model control dsRNA (dsGFP) remained detectable on buds throughout the entire 3 d exposure period. When applied at 5 mu g/mu L, ds alpha COP induced significant alpha COP silencing 3 d after dietary exposure to buds treated with this ds alpha COP concentration. We also observed a trend of increased alpha COP silencing with increasing concentrations of ds alpha COP at both 3 and 6 d. Furthermore, we observed a marginally significant and significant reduction in B. aeneus survival at 10 and 15 d, respectively. Our results suggest potential for developing a SIGS approach to B. aeneus management-though further experiments are needed to more fully understand this potential.

Original languageEnglish
Article number769
Number of pages8
JournalInsects
Volume11
Issue number11
DOIs
Publication statusPublished - Nov 2020

Keywords

  • RNA interference
  • Meligethes aeneus
  • rapeseed
  • biopesticide
  • insecticide
  • Nitidulidae
  • Coleoptera
  • INSECTICIDES

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