Katterinne Prentice1,2,3, Olivier Christiaens1, Ine Pertry4, Ana Bailey5, Chuck Niblett5, Marc Ghislain3, Godelieve Gheysen2, Guy Smagghe1. 1. Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium. 2. Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium. 3. International Potato Centre (CIP), Genomics and Biotechnology Programme, Nairobi, Kenya. 4. International Plant Biotechnology Outreach, VIB, Ghent, Belgium. 5. Venganza Inc., St Augustine, FL, USA.
Abstract
BACKGROUND: RNA interference (RNAi) technology can potentially serve as a suitable strategy to control the African sweet potato weevil Cylas puncticollis (SPW), which is a critical pest in sub-Saharan Africa. Important prerequisites are required to use RNAi in pest control, such as the presence of an efficient RNAi response and the identification of suitable target genes. RESULTS: Here we evaluated the toxicity of dsRNAs targeting essential genes by injection and oral feeding in SPW. In injection assays, 12 of 24 dsRNAs were as toxic as the one targeting Snf7, a gene used commercially against Diabrotica virgifera virgifera. Three dsRNAs with high insecticidal activity were then chosen for oral feeding experiments. The data confirmed that oral delivery can elicit a significant toxicity, albeit lower compared with injection. Subsequently, ex vivo assays revealed that dsRNA is affected by degradation in the SPW digestive system, possibly explaining the lower RNAi effect by oral ingestion. CONCLUSION: We conclude that the full potential of RNAi in SPW is affected by the presence of nucleases. Therefore, for future application in crop protection, it is necessary constantly to provide new dsRNA and/or protect it against possible degradation in order to obtain a higher RNAi efficacy.
BACKGROUND: RNA interference (RNAi) technology can potentially serve as a suitable strategy to control the African sweet potato weevilCylas puncticollis (SPW), which is a critical pest in sub-Saharan Africa. Important prerequisites are required to use RNAi in pest control, such as the presence of an efficient RNAi response and the identification of suitable target genes. RESULTS: Here we evaluated the toxicity of dsRNAs targeting essential genes by injection and oral feeding in SPW. In injection assays, 12 of 24 dsRNAs were as toxic as the one targeting Snf7, a gene used commercially against Diabrotica virgifera virgifera. Three dsRNAs with high insecticidal activity were then chosen for oral feeding experiments. The data confirmed that oral delivery can elicit a significant toxicity, albeit lower compared with injection. Subsequently, ex vivo assays revealed that dsRNA is affected by degradation in the SPW digestive system, possibly explaining the lower RNAi effect by oral ingestion. CONCLUSION: We conclude that the full potential of RNAi in SPW is affected by the presence of nucleases. Therefore, for future application in crop protection, it is necessary constantly to provide new dsRNA and/or protect it against possible degradation in order to obtain a higher RNAi efficacy.
Authors: Baida Alshukri; Federica Astarita; Mushtaq Al-Esawy; Hesham Mohamed El Sayed Abd El Halim; Francesco Pennacchio; Angharad Margaret Roscoe Gatehouse; Martin Gethin Edwards Journal: Pest Manag Sci Date: 2019-07-29 Impact factor: 4.845
Authors: Kalynka G do Livramento; Natália C Freitas; Wesley P F Máximo; Ronald Zanetti; Luciano V Paiva Journal: Insects Date: 2018-02-08 Impact factor: 2.769