Qualitative LC-MS-based Protein Profiling of Helicoverpa armigera (Hübner, 1808) Larval Midgut under Emamectin Benzoate Stress

Abstract

Helicoverpa armigera is a major polyphagous pest with an immense potential to develop resistance to conventional insecticides. Emamectin benzoate (EMB), a compound derived from abamectin, is widely used for its efficacy against lepidopteran larvae. Despite several studies revealing its toxic and growth regulatory effects, information regarding its effects on midgut protein composition remains limited. In this study, we examined the midgut protein profile of H. armigera larvae following exposure to dietary EMB. Midgut proteins were separated by SDS-PAGE and differentially obtained bands were identified using liquid chromatography-mass spectrometry (LC-MS). The EMB-treated larvae showed a total of 39 differential proteins, among which 35 proteins were differentially deleted while just 4 proteins were differentially detected. The chief differentially absent proteins were found to be associated with metabolism, protein processing, signal transduction and stress response, while the differentially detected proteins were related to glycolysis and signal transduction. The differential absence/presence of these proteins indicated their plausible role in causing the disrupted metabolic and physiological processes in EMB-treated H. armigera larvae. This study provides qualitative molecular insights into the midgut-level responses of H. armigera to EMB exposure. However, further quantitative estimation of the altered levels of proteins can help formulation of an effective management strategy.