Targeting the potassium ion channel genes SK and SH as a novel approach for control of insect pests: efficacy and biosafety. Issue 9 (29th July 2019)

• Record Type: Journal Article
• Authors: Alshukri, Baida; Astarita, Federica; Al‐Esawy, Mushtaq; El Halim, Hesham Mohamed El Sayed Abd; Pennacchio, Francesco; Gatehouse, Angharad Margaret Roscoe; Edwards, Martin Gethin
• Is Part Of: Pest management science. Volume 75:Issue 9(2019)
• Page Start: 2505
• Page End: 2516
• Publication Date: 2019-07-29
• Subjects: insect control -- RNAi -- potassium ion channels -- biosafety -- Tribolium castaneum -- Apis mellifera; Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.5516
• Languages: English
• ISSNs: 1526-498X

Abstract

Abstract: BACKGROUND: Potassium ion channels play a critical role in the generation of electrical signals and thus provide potential targets for control of insect pests by RNA interference. RESULTS: Genes encoding the small conductance calcium‐activated potassium channel ( SK ) and the voltage‐gated potassium channel ( SH ) were knocked down in Tribolium castaneum by injection and oral delivery of dsRNA (dsTcSK and dsTcSH, respectively). Irrespective of the delivery mechanism a dose‐dependent effect was observed for knockdown (KD) of gene expression and insect mortality for both genes. Larvae fed a 400 ng dsRNA mg –1 diet showed significant gene ( P < 0.05) knockdown (98% and 83%) for SK and SH, respectively, with corresponding mortalities of 100% and 98% after 7 days. When injected (248.4 ng larva –1 ), gene KD was 99% and 98% for SK and SH, causing 100% and 73.4% mortality, respectively. All developmental stages tested (larvae, early‐ and late‐stage pupae and adults) showed an RNAi‐sensitive response for both genes. LC50 values were lower for SK than SH, irrespective of delivery method, demonstrating that the knockdown of SK had a greater effect on larval mortality. Biosafety studies using adult honeybee Apis mellifera showed that there were no significant differences either in expression levels or mortality of honeybees orally dosed with dsTcSK and dsTcSH compared to control‐fed bees. Similarly, there was no significant difference in the titre of deformed wing virus, used as a measure of immune suppression, between experimental and control bees. CONCLUSION: This study demonstrates the potential of using RNAi targeting neural receptors as a technology for the control of T. castaneum . © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Abstract : Potassium ion channels of the central nervous system are essential for insect survival, thus providing effective targets for control. We demonstrate the use of dsRNA molecules targeting these ion channels as potential biopesticides.