Benzothiazole kills Meloidogyne incognita quickly by inhibiting GST to trigger ROS bursting

Root-knot nematodes (Meloidogyne incognita) present a significant threat to global agriculture, and the development of multi-drug resistance in these nematodes exacerbates this problem. Benzothiazole, a heterocyclic compound has been reported as a potential nematicide, however, its mode of action is not fully understood. This study aims to elucidate the nematicidal mechanism of benzothiazole against M. incognita. In the toxicity assays, benzothiazole exhibited rapid and effective nematocidal activity, significantly compromising egg masses and inhibiting egg hatching while killing newly hatched second-stage juveniles (J2s) of M. incognita. Microscopic observations revealed that after 48 h of incubation, a marked reduction in protein and carbohydrate levels within the J2s was observed. Notably, benzothiazole at a concentration of 14 mmol/L significantly inhibits glutathione S-transferase (GST) enzyme activity, leading to the accumulation of reactive oxygen species (ROS), ultimately resulting in rapid nematode death. Molecular docking and dynamics simulations demonstrated that benzothiazole forms a stable complex with GST, thereby disrupting its antioxidant function. Furthermore, in pot experiments, benzothiazole effectively reduced the gall formations of M. incognita on tomato roots. Overall, this novel inhibitory mechanism of glutathione S-transferase (GST) differs from that of the neurotoxicant abamectin, which targets glutamate-gated chloride channels (GluCl). This mechanism holds significant promise for the development of environmentally friendly nematicides. It offers a potential solution to the growing problem of multidrug resistance in root-knot nematodes and could help mitigate the substantial economic losses caused by these pests in global agriculture.