Pyraclostrobin-induced reproductive and intergenerational developmental toxicity in zebrafish: Modulatory effects of microplastics

Quinone outside inhibitor (QoI) fungicides are widely applied in agriculture for their high efficacy and broad-spectrum activity, raising ecological concerns. The reproductive and intergenerational toxicities of pyraclostrobin (PYR), a representative QoI fungicide, particularly when coexisting with emerging contaminants such as microplastics (MPs), remain inadequately characterized. In this study, adult zebrafish (Danio rerio) were employed to assess the reproductive toxicity and maternal transfer potential of PYR under single and combined exposure with polyethylene microplastics (PE-MPs). PYR exhibited tissue-specific bioaccumulation, with the highest concentrations detected in intestinal and hepatic tissues, followed by gills, brain, gonads, and muscle. Notably, co-exposure with PE-MPs altered PYR distribution by enhancing its accumulation in the intestine and gills, and reducing levels in the liver, brain, and gonads in a concentration-dependent manner. Both PYR and its combination with PE-MPs significantly impaired reproductive performance and intergenerational fitness, with effects extending to the F1 generation. Interestingly, combined exposure to PYR and PE-MPs attenuated some of these impairments observed with PYR alone, and aged PE-MPs (1.0 mg/L) induced less pronounced transcriptional disturbances than virgin MPs. This comprehensive analysis provides critical insights into the ecological risk assessment of QoI fungicides and their interaction with microplastic pollutants in aquatic ecosystems.