Identification and Expression Analysis of Antennal UDP‐Glycosyltransferase Genes Associated With Odorant Degradation in the Asian Citrus Psyllid, <i>Diaphorina citri</i>

Olfactory perception is essential for mating, host location, and oviposition in insects. Odorant degrading enzymes (ODEs), such as antennal UDP-glycosyltransferases (UGTs), clear redundant odorant molecules to recover olfactory capabilities. In this study, four antenna-abundant DcUGT genes (i.e., DcUGT2B14, DcUGT378A1, DcUGT381A1, and DcUGT381A2) were identified in Asian citrus psyllid Diaphorina citri, the main vector of citrus Huanglongbing pathogens. These genes were classified into three separate subclades, where DcUGT381A1 and DcUGT381A2 clustered together. qRT-PCR analyses showed that these DcUGTs exhibited antenna-biased expression profiles in both sexes and were constantly expressed from the first instar nymph to the adult stages. Moreover, they exhibited diverse responses to host plant odorants; specifically, exposure to linalool and myrcene upregulated the expressions of DcUGT2B14 and DcUGT381A2, while citral and myrcene exposure increased the expression levels of DcUGT381A1, suggesting their important roles in odorant processing. Molecular docking analysis predicted the key residues of DcUGTs in degrading odorants, indicating that hydrophobic interactions facilitate the binding affinity of DcUGT2B14, DcUGT381A2, and DcUGT381A1 with myrcene. These results provide the comprehensive expression analysis of antennal UGT genes in D. citri, highlighting their possible role in odorant degradation and potential as targets for pest management.