Integration of Physiological, Biochemical, and Transcriptomic Analyses Reveals the Multifaceted Toxicity of Tricyclazole in Eriocheir sinensis

Tricyclazole (TRCZ), a widely used fungicide in rice-crab coculture, poses a potential risk to the Chinese mitten crab (Eriocheir sinensis). This study aimed to elucidate its hepatopancreatic toxicity mechanism by integrating physiological, biochemical, and transcriptomic analyses. We determined a 96 h LC50 of 54.28 mg/L and a safe concentration of 22.09 mg/L. The effects of subchronic (28 days) and acute (96 h) exposure were investigated in the E. sinensis. TRCZ exposure induced oxidative stress, immune dysregulation, metabolic disruption, and apoptosis, leading to histopathological damage in the hepatopancreas of E. sinensis. Transcriptomic profiling revealed 4809 differentially expressed genes, with the MAPK signaling pathway being significantly enriched. RNA interference targeting Ras confirmed the pivotal role of the Ras-MAPK cascade in mediating TRCZ-induced injury. Our findings reveal the mechanism of TRCZ toxicity and provide an insight for its risk assessment and safe application in rice-crab coculture systems.