Short-term high-intensity UV-B exposure alters glycogen and protein metabolism through insulin signaling gene modulation in Myzus persicae.

UV-B radiation is a crucial environmental stressor that affects insect growth, development, and reproduction. Insulin genes in insects coordinate nutrient availability with growth, development, and stress responses. However, studies related to the role of insulin genes affecting these parameters in aphids under UV-B stress are limited. Therefore, we intended to define the molecular mechanisms employed by Myzus persicae to resist UV-B exposure. Our study focused on three crucial insulin signaling pathway genes: Glycogen synthase kinase 3 (GSK3), Ribosomal protein S6 kinase (S6K) and Target of rapamycin (TOR). For these analyses, M. persicae was irradiated with UV-B for different exposure times (0 (as control), 20, 40, 60, and 80 min), and mRNA expression levels of target genes were monitored using quantitative reverse transcription polymerase chain reaction (qRT-PCR) following irradiation. The results revealed that insulin signaling genes were significantly upregulated across different UV-B exposure times and aided in stress tolerance. Knocking down these genes showed a significant reduction in adult body weight, survival rates, fecundity, as well as reduced glycogen and protein levels in M. persicae. Results indicate that M. persicae utilizes the insulin signaling pathway during metabolic regulation, homeostasis, and stress responses. This research expands our understanding of insect stress physiology and provides insights that may contribute to pest management strategies in changing environmental conditions.