Shrimp dihydrodiol dehydrogenase modulates ROS via the P450 pathway to resist Vibrio parahaemolyticus-induced AHPND

Dihydrodiol dehydrogenase (DHDH) participates in the cytochrome P450 pathway and ROS regulation in mammals, but its role in shrimp immunity remains unclear. Here, we characterized PvDHDH in Penaeus vannamei and explored its function in ROS homeostasis and anti AHPND causing Vibrio parahaemolyticus (V.p_AHPND) infection. Sequence analysis revealed PvDHDH contains a conserved GFO_IDH_MocA domain, with high homology to crustacean and vertebrate DHDH, and is predominantly expressed in the hepatopancreas. Under physiological conditions, PvDHDH knockdown dysregulated cytochrome P450 pathway genes (upregulating PvCYP1A, PvCYP3A4, and PvCBR1; downregulating PvUGT) and increased total ROS. Under V.p_AHPND stress, PvDHDH expression was specifically upregulated, and its knockdown further perturbed P450 pathway genes, elevated ROS/H₂O₂, and increased V.p_AHPND abundance. These results indicate PvDHDH modulates ROS via affecting cytochrome P450 pathway genes to contributes to resist V.p_AHPND, providing novel insights into shrimp innate immunity.