<scp>BarH2</scp> regulates odorant binding protein 6 expression to mediate 2,3‐butanediol recognition in female <i>Callosobruchus chinensis</i>

Abstract BACKGROUND The insect olfactory system plays an important role in guiding chemical‐driven behaviors, such as host selection, oviposition, and mating. Odorant‐binding proteins (OBPs) serve as a bridge for transmitting chemical signals in insects; however, the transcriptional regulation of their expression patterns remains unknown. RESULTS In this study, we demonstrated that CchiBarH2 regulates the expression of CchiOBP6 , mediating the olfactory recognition of female Callosobruchus chinensis for 2,3‐butanediol. CchiBarH2 directly bound to the promoter region of CchiOBP6 and enhanced the transcriptional activity of CchiOBP6 in vitro using a dual‐luciferase reporter system and electrophoretic mobility shift assay (EMSA). RNAi‐mediated silencing of CchiBarH2 significantly decreased the expression level of CchiOBP6 , weakened the electrophysiological responses, and the attraction of C. chinensis females to 2,3‐butanediol disappeared simultaneously. CONCLUSION These results revealed that CchiBarH2 regulated the expression of CchiOBP6 , thereby mediating the EAG and behavioral responses of female C. chinensis to 2,3‐butanediol. These findings also provide potential molecular targets for disrupting olfactory‐driven behaviors in agricultural pest management. © 2026 Society of Chemical Industry.