Combined transcriptome and metabolome analysis reveals the toxic effects of antimony on the earthworm

Antimony (Sb) poses a significant ecological threat. This study combines biochemical, pathological, transcriptome, and metabolome analyses to assess the short-term (14-day) toxic impact of two Sb levels (25 mg/kg and 125 mg/kg) on earthworms (Eisenia fetida). Higher Sb concentration caused severe intestinal damage, elevated metallothionein (MT) levels, and reduced antioxidant capacity. Metabolome analysis identifies 404 and 1698 significantly differential metabolites in the two groups. Metabolites such as S(-)-cathinone, N-phenyl-1-naphthylamine, serotonin, 4-hydroxymandelonitrile, and 5-fluoropentylindole contributed to the metabolic responses to Sb stress. Transcriptome analysis shows increased chitin synthesis as a protective response, impacting amino sugar and nucleotide sugar metabolism for cell wall synthesis and damage repair. Integrated analysis indicated that 5 metabolite-gene pairs were found in two Sb levels and 11 enriched pathways were related to signal transduction, carbohydrate metabolism, immune system, amino acid metabolism, digestive system, and nervous system. Therefore, the integration of multiomics approaches enhanced our comprehension of the molecular mechanisms underlying the toxicity of Sb in E. fetida.