Disruption of paramyosin compromises muscle integrity and alters systemic trehalose metabolism in Helicoverpa armigera.

Trehalose is a principal circulating sugar in insects, maintaining a critical balance between energy supply and storage through systemic insulin signalling. Among different tissues, insect muscle functions as a metabolic hub, coordinating trehalose utilization and glucose uptake to sustain energy homeostasis. In Helicoverpa armigera, we examined whether paramyosin (key muscle gene) silencing influence carbohydrate metabolism. HaPrm silencing led to muscle defects and delayed pupation, indicating a crucial role of HaPrm in development. Transcriptomics revealed dysregulation of genes involved in carbohydrate metabolism and insulin-mTOR signalling. Notably, expression and enzymatic activities of HaTPS/TPP and HaTreh(s) were reduced in HaPrm-silenced insects, accompanied by their altered metabolite intermediate levels. Given that trehalose metabolism fuels both glycolysis and glycogen synthesis, HaPrm silencing also altered the expression of glycolytic, glycogen metabolism and energy-sensing genes. Metabolomics further demonstrated differential accumulation of intermediates from glycolysis, glycogen recycling, the TCA cycle and amino acid metabolism. Moreover, insulin-mTOR signalling genes and the glucose-sensing transcription factor were significantly affected, highlighting the sensitivity of nutrient-sensing mechanisms to HaPrm silencing. Taken together, these results suggest that HaPrm disruption affects muscle integrity and is linked to changes in insulin-mTOR signalling and trehalose metabolism. These data highlight the close relationship between muscle architecture and energy homeostasis in H. armigera.