Molecular EntomologyTrehalose promotes the response of CYP genes in Tribolium castaneum (Coleoptera: Tenebrionidae) to high-CO2 stress.

Cytochrome P450 monooxygenases (CYP450) and trehalose play a significant detoxification role under high CO2 stress. Notably, CYP450 significantly affects trehalose metabolism of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), a devastating stored pest. To explore whether trehalose enhances CYP gene responses to CO2 stress, investigations were conducted on the 95% CO2 tolerance in 8th-instar T. castaneum larvae, whose specific CYP genes-TcCYP4BN1, TcCYP9F2, and TcCYP9AB1-were silenced, across different trehalose dietary regimes (50% flour + 50% trehalose or 100% trehalose). The 95% CO2 tolerance response was systematically evaluated through multi-dimensional analysis of gene expression levels, carbohydrate contents, and enzyme activities. Results indicated that compared with the 50% flour + 50% trehalose feeding regimen, trehalose-only diet groups exhibited downregulation of trehalose metabolism-related genes, with the notable exception of the dsCYP9F2 experimental group. As to carbohydrate contents, glucose content increased significantly on 100% trehalose diet by inhibiting the expression of TcCYP9AB1, but it decreased in the other 2 groups, a pattern that also held true for glycogen. Together, these results demonstrate that trehalose does enhance the response of CYP genes to CO2 stress, and that TcCYP9AB1 is more responsible for modulating trehalose metabolism. Future research could investigate the molecular mechanisms underlying these regulatory processes and their practical applications, potentially enhancing biocontrol techniques and advancing pest management solutions.