| Summary: | The Colorado potato beetle (<i>Leptinotarsa decemlineata</i> (Say)) can cause extensive damage to agricultural crops worldwide and is a significant insect pest. This insect is notorious for its ability to evade various strategies deployed to control its spread and is known for its relative ease in developing resistance against different insecticides. Various molecular levers are leveraged by <i>L. decemlineata</i> for this resistance to occur, and a complete picture of the genes involved in this process is lacking. While small non-coding RNAs, including miRNAs, are differentially expressed in insects exposed to insecticides, levels of transcript coding for proteins underlying their synthesis remain to be characterized fully. The overarching objective of this work aims to fill that gap by assessing the expression of such targets in <i>L. decemlineata</i> exposed to cyantraniliprole and thiamethoxam. The expression status of <i>Ago1</i>, <i>Ago2</i>, <i>Ago3</i>, <i>Dcr2a</i>, <i>Dcr2b</i>, <i>Expo-5</i>, <i>Siwi-1</i> and <i>Siwi-2</i> transcripts were quantified via qRT-PCR in adult <i>L. decemlineata</i> treated with low and high doses of these compounds for different lengths of time. Variation in <i>Ago1</i> and <i>Dcr2b</i> expression was notably observed in <i>L. decemlineata</i> exposed to cyantraniliprole, while thiamethoxam exposure was associated with the modulation of <i>Dcr2a</i> and <i>Siwi-1</i> transcript levels. The down-regulation of <i>Ago1</i> expression in <i>L. decemlineata</i> using dsRNA, followed by cyantraniliprole treatment, was associated with a reduction in the survival of insects with reduced <i>Ago1</i> transcript expression. Overall, this work presents the insecticide-mediated modulation of transcripts associated with small non-coding RNA processing and showcases <i>Ago1</i> as a target to further investigate its relevance in cyantraniliprole response.
|
|---|