Novel Mechanisms of Fumigant Action: Multi-Omics Analysis Reveals Dimethyl Disulfide Disrupts Chitin Biosynthesis and Metabolic Homeostasis to Exert Ovicidal Activity Against Meloidogyne incognita eggs

Eggs of the root-knot nematode Meloidogyne incognita are critical targets for the management of soilborne diseases. This study aimed to elucidate the ovicidal mechanism of the fumigant dimethyl disulfide (DMDS). The results demonstrated that DMDS efficiently inhibited egg hatching (>97%). Mechanistically, DMDS suppressed chitin biosynthesis and the expression of related genes (e.g., Minc_7846, Minc_6401), leading to severe disruption of eggshell ultrastructure. Multi-omics analyses further revealed that DMDS not only triggered intense oxidative stress and detoxification responses but also interfered with glycosylation and energy metabolism, thereby disturbing cellular homeostasis. In conclusion, DMDS synergistically blocks embryonic development and egg hatching by directly compromising eggshell integrity and inducing systemic metabolic imbalance, highlighting chitin metabolism as a central ovicidal target.