Functional characterization of CYP389B1 suggests a role in carotenoid hydroxylation and pigmentation in Tetranychus pueraricola

Abstract

Spider mites are globally important agricultural pests, many of which exhibit red body coloration associated with carotenoid accumulation. Although previous studies have implicated the cytochrome P450 gene CYP389B1 in pigmentation, its biochemical function remains unclear. Here, we functionally characterized CYP389B1 in Tetranychus pueraricola using an integrative approach combining heterologous expression, pigment profiling, and RNA interference. Heterologous expression of CYP389B1 in a ¦Â-carotene-producing Escherichia coli system resulted in increased levels of zeaxanthin, suggesting a role in carotenoid hydroxylation. Developmental expression analysis revealed that CYP389B1 level increased progressively and peaked in adults, coinciding with changes in carotenoid composition. RNAi-mediated knockdown of CYP389B1 led to the accumulation of ¦Â-carotene and a reduction in downstream zeaxanthin, supporting its involvement in carotenoid conversion. In addition, gene silencing was associated with reduced fecundity and survival. Together, these results suggest that CYP389B1 contributes to carotenoid metabolism and pigmentation in T. pueraricola, and may play a role in physiological processes linked to fitness. This study expands our understanding of the potential roles of cytochrome P450 enzymes in carotenoid-based coloration in arthropods, and offers a promising molecular target for RNAi-based pest management strategies.