Abstract
Hypoxia-inducible factor (HIF) is recognized as a key transcription factor via regulating a variety of molecular responses to hypoxia, although the details are still unclear. In this study, based on bioinformatics analysis, the expression of the HIF-1α gene in T. castaneum (TcHIF-1α) under hypoxic treatments was determined. After TcHIF-1α knockdown by injecting dsRNA, larval mortality, the expression levels of oxidative stress-related genes, and enzymatic activities were measured; DNA damage was also evaluated through single cell gel electrophoresis. The result indicated that TcHIF-1α is highly conserved in structure. TcHIF-1α exhibited distinct temporal patterns, with a peak after 72 h of exposure to 2% O(2). Following TcHIF-1α knockdown, a significant increase in larval mortality (17.44 ± 5.91%) and moderate DNA damage level was found. This might be accompanied by ROS accumulation, lipid peroxidation (LPO), and suppression of antioxidant enzymatic activities. The expression of genes involved in ROS synthesis (e.g., NOX) was significantly upregulated, whereas genes responsible for mitigating oxidative stress (e.g., OGG1, XRCC1, PARP1, SOD1a) were markedly downregulated. These findings elucidate the critical role of HIF-1α in insect hypoxia adaptation by regulating the antioxidative stress, highlighting its potential as a promising target for developing novel pest control strategies.