Molecular chaperone heat shock protein 70 mediates thermotolerance and insecticide resistance in Aphis glycines Matsumura (Hemiptera: Aphididae)

Abstract

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major agricultural pest that causes substantial yield losses in soybean production. Heat shock proteins (Hsps) are evolutionarily conserved molecular chaperones that play critical roles in regulating cellular responses to abiotic and biotic stresses. In this study, we identified an Hsp70 gene (AglyHsp70) from the soybean aphid genome and investigated its expression profile and role in stress tolerance under thermal and insecticide challenges. Sequence alignment and phylogenetic analysis revealed that AglyHsp70 shares strong homology with Hsp70 proteins from other insect species. Developmental expression analysis showed that AglyHsp70 was most abundantly expressed in first-instar nymphs. Under heat stress, AglyHsp70 expression was strongly induced but rapidly returned to baseline levels after recovery from both heat and cold shocks. Exposure to imidacloprid significantly upregulated AglyHsp70 expression in a concentration- and time-dependent manner. Moreover, RNAi-mediated knockdown of AglyHsp70 markedly increased soybean aphid mortality under heat stress and at specific concentrations of imidacloprid. Collectively, these findings demonstrate that AglyHsp70 plays an essential role in stress tolerance against both thermal and chemical stressors in A. glycines. This study provides novel insights into the molecular mechanisms of stress adaptation in soybean aphids and highlights potential molecular targets for sustainable pest management strategies.