Evaluation of the Reproductive Toxicity of Fluopimomide in Meloidogyne incognita and Caenorhabditis elegans

Abstract

Fluopimomide is a new pesticide that is widely applied in agriculture; however, the effects and molecular mechanisms of fluopimomide in inhibiting nematode reproduction remain unknown. In this study, the effects of fluopimomide on the development and infection of Meloidogyne incognita and the reproductive toxicity in Caenorhabditis elegans were evaluated. Results showed that, in comparison to inoculated control, fluopimomide at 0.33, 0.67, and 1.0 mg/kg soil significantly (p < 0.05) delayed M. incognita development and decreased the reproduction in pot experiments. Fluopimomide notably reduced the galls index with a control effect of 78.6%, 67.9%, and 50.0%, respectively. In addition, a dose–response relationship existed between the brood size and germ cell number of C. elegans and fluopimomide concentrations. Compared with the control group, fluopimomide at 1.0 and 5.0 mg/L notably (p < 0.001) increased the number of cell corpses per gonad in the N2 strain of C. elegans by 8.8- and 14.4-fold, respectively. The number of cell corpses per gonad was similar between the fluopimomide treated worms and the control group in mutants of ced-3, ced-4, and ced-9. Further evidence revealed fluopimomide significantly enhanced the expression of cep-1, egl-1, and clk-2, while no obvious effects were observed in their mutants. Taken together, these results indicated that fluopimomide inflicted DNA damage and induced the core apoptosis pathway caused by germ-cell apoptosis, leading to the reduction of the brood size of C. elegans.