Systematic assessment of cyflumetofen toxicity in soil-earthworm (Eisenia fetida) microcosms

Cyflumetofen was widely applied in agriculture with its excellent acaricidal effect. However, the impact of cyflumetofen on the soil non-target organism earthworm (Eisenia fetida) is unclear. This study aimed to elucidate the bioaccumulation of cyflumetofen in soil-earthworm systems and the ecotoxicity of earthworms. The highest concentration of cyflumetofen enriched by earthworms was found on the 7th day. Long-term exposure of earthworms to the cyflumetofen (10 mg/kg) could suppress protein content and increases Malondialdehyde content leading to severe peroxidation. Transcriptome sequencing analysis demonstrated that catalase and superoxide-dismutase activities were significantly activated while genes involved in related signaling pathways were significantly upregulated. In terms of detoxification metabolic pathways, high concentrations of cyflumetofen stimulated the number of Differentially-Expressed-Genes involved in the detoxification pathway of the metabolism of glutathione. Identification of three detoxification genes (LOC100376457, LOC114329378, and JGIBGZA-33J12) had synergistic detoxification. Additionally, cyflumetofen promoted disease-related signaling pathways leading to higher disease risk, affecting the transmembrane capacity and cell membrane composition, ultimately causing cytotoxicity. Superoxide-Dismutase in oxidative stress enzyme activity contributed more todetoxification. Carboxylesterase and glutathione-S-transferase activation play a major detoxification role in high -concentration treatment. Altogether, these results contribute to a better understanding of toxicity and defense mechanisms involved in long-term cyflumetofen exposure in earthworms.

Automated summary

Cyflumetofen has been widely used in agriculture due to its strong acaricidal effect. However, its impact on non-target organisms like earthworms remains unclear. This study aimed to investigate the bioaccumulation of cyflumetofen in soil-earthworm systems and the resulting ecotoxicity. The findings showed that the highest concentration of cyflumetofen accumulated by earthworms was observed on the 7th day. Long-term exposure to cyflumetofen suppressed protein content and increased Malondialdehyde content in earthworms, leading to severe peroxidation. Transcriptome sequencing analysis revealed significant activation of catalase and superoxide-dismutase activities, as well as upregulation of genes involved in related signaling pathways. Moreover, high concentrations of cyflumetofen stimulated the detoxification pathway of the metabolism of glutathione. The study also identified three detoxification genes with synergistic detoxification effects. Additionally, cyflumetofen promoted disease-related signaling pathways, affecting the transmembrane capacity and cell membrane composition, ultimately causing cytotoxicity. Superoxide-Dismutase played a significant role in detoxification through oxidative stress enzyme activity. Carboxylesterase and glutathione-S-transferase activation were also important in high-concentration treatment. These results enhance our understanding of the toxicity and defense mechanisms associated with long-term cyflumetofen exposure in earthworms.