Transcriptomic analysis reveals decreased expression of detoxification genes in Caenorhabditis elegans exposed to mepanipyrim and cyprodinil: Implications for multigenerational exposure effects

The broad-spectrum fungicides mepanipyrim (Mep) and cyprodinil (Cyp) have been reported to be used worldwide to control gray mold of fruit crops. Consequently, they are often detected in the water and food items. However, the impacts and potential mechanisms of these two pesticides on environmental organisms remain unclear. Utilizing Caenorhabditis elegans (C. elegans) as the model, the toxic effects and mechanisms were analyzed after Mep and Cyp exposure over four generations (P₀-F₃). The results showed that Mep and Cyp at concentrations over 0.1 µg/L affected the motility behavior, while 1.0 µg/L dosage and above inhibited the growth of C. elegans. In addition, multigenerational exposure could significantly impair both locomotion and development of C. elegans even at 0.01 µg/L dosage. Notably, constant exposure resulted in the function abnormalities of cholinergic, dopaminergic and GABAergic neurons, as well as the accumulation of ROS. Further transcriptome analysis showed reduced expression of 14 genes and 26 genes in xenobiotic metabolic pathway following Mep and Cyp exposure, respectively. The buildup of Mep/Cyp and ROS might have led to nerve impairment and behavioral abnormality. These findings enhanced understanding of the toxic effects of Mep and Cyp and provided insights into their eco-toxicological evaluation.