Effects of ecotoxicity of penoxsulam single and co-exposure with AgNPs on Eisenia fetida

Penoxsulam (PNX) and silver nanoparticles (AgNPs) are likely to coexist in soils due to continuous use. However, the ecotoxicity of PNX in earthworms and the effect of AgNPs on PNX toxicity are unknown. Therefore, the toxicity of PNX (0.05, 0.5, and 2.5 mg/kg) single and co-exposure with AgNPs (10 mg/kg) after 28 and 56 days on Eisenia fetida (E. fetida) was investigated from biochemical, genetic, histopathological, and transcriptomic aspects. The results showed that the low concentration of PNX (0.05PNX) had almost no effect on the biochemical level of E. fetida. However, the addition of AgNPs resulted in 0.05PNX causing E. fetida to produce excessive reactive oxygen species, and the activity of antioxidant and detoxification enzymes were interfered, resulting in lipid peroxidation and DNA damage. From the genetic level, even the lowest concentration of PNX can significantly interfere with the expression of functional genes, thus inducing oxidative stress and apoptosis and inhibited reproductive behavior in E. fetida. The integrated biomarker response results at the biochemical and genetic levels showed that the comprehensive toxicity of PNX and PNX + AgNPs on E. fetida was PNX dosedependent. And the toxicity of all co-exposure groups was greater than that of the PNX only exposure groups. Furthermore, the addition of AgNPs significantly increased the damage of PNX on E. fetida intestinal tissue. Meanwhile, transcriptomic analysis showed that PNX + AgNPs had a greater effect on E. fetida than PNX single, and multiple pathways related to oxidative stress, inflammation, and cellular process regulation were disturbed. These results provide a basis for comprehensive evaluation of the ecotoxicity of PNX and confirm that the AgNPs does increase the ecotoxicity of PNX in soil environment.

Automated summary

This study investigated the ecotoxicity of Penoxsulam (PNX) and silver nanoparticles (AgNPs) on Eisenia fetida (E. fetida). The results showed that low concentrations of PNX had little effect on E. fetida at the biochemical level, but the addition of AgNPs increased the production of reactive oxygen species and disrupted antioxidant and detoxification enzymes, resulting in lipid peroxidation and DNA damage. Furthermore, even the lowest concentration of PNX significantly affected the expression of functional genes, inducing oxidative stress and apoptosis and inhibiting reproductive behavior in E. fetida. The addition of AgNPs further increased the damage of PNX on E. fetida's intestinal tissue. Transcriptomic analysis revealed that PNX + AgNPs had a greater impact on E. fetida than PNX alone, affecting multiple pathways related to oxidative stress, inflammation, and cellular processes.