Spinosad‐associated modulation of select cytochrome P450s and glutathione S‐transferases in the Colorado potato beetle, Leptinotarsa decemlineata. Issue 3 (22nd December 2022)

• Record Type: Journal Article
• Authors: Bastarache, Pierre; Bouafoura, Raed; Omakele, Enock; Moffat, Chandra E.; Vickruck, Jess L.; Morin, Pier Jr
• Is Part Of: Archives of insect biochemistry and physiology. Volume 112:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-22
• Subjects: Colorado potato beetles -- cytochrome P450s -- glutathione S‐transferases -- insecticide response -- RNA interference -- spinosad; Insects -- Physiology -- Periodicals; Insect biochemistry -- Periodicals; 595.701572
• DOI: 10.1002/arch.21993
• Languages: English
• ISSNs: 0739-4462

Abstract

Abstract: The Colorado potato beetle ( Leptinotarsa decemlineata (Say)) is an insect pest that threatens potato crops. Multiple options exist to limit the impact of this pest even though insecticides remain a primary option for its control. Insecticide resistance has been reported in Colorado potato beetles and a better understanding of the molecular players underlying such process is of utmost importance to optimize the tools used to mitigate the impact of this insect. Resistance against the insecticide spinosad has been reported in this insect and this work thus aims at exploring the expression of targets previously associated with insecticide response in Colorado potato beetles exposed to this compound. Amplification and quantification of transcripts coding for cytochrome P450s and glutathione S‐transferases were conducted via qRT‐PCR in insects treated with varying doses of spinosad and for different time duration. This approach notably revealed differential expression of CYP6a23 and CYP12a5 in insects exposed to low doses of spinosad for 4 h as well as modulation of CYP6a13, CYP6d4, GST, GST1, and GST1‐Like in insects treated with high doses of spinosad for the same duration. RNAi‐based targeting of CYP4g15 and CYP6a23 was associated with marked reduction of transcript expression 7 days following dsRNA injection and reduction of the former had a marked impact on insect viability. In general, results presented here provide novel information regarding the expression of transcripts relevant to spinosad response in Colorado potato beetles and reveal a novel target to consider in the development of RNAi‐based strategies aimed at this potato pest. Research highlights: qRT‐PCR approach performed in spinosad‐treated Leptinotarsa decemlineata . Variation of cytochrome P450s and glutathione S‐transferases in spinosad‐exposed insects. RNAi‐based reduction of CYP4g15 levels associated with increased insect mortality. Abstract : This study explores the expression status of multiple transcripts coding for cytochrome P450s and glutathione S‐transferases in the Colorado potato beetle Leptinotarsa decemlineata exposed to spinosad using qRT‐PCR. It subsequently investigates the impact of RNAi‐based downregulation of select transcript targets expression on spinosad response in this potato pest and identifies CYP4g15 as a target of interest given that its modulation correlates with greater insect lethality.