GC-MS and molecular docking analysis of mustard seed cake-derived compounds: Evaluating their nematotoxic efficacy against Meloidogyne javanica for sustainable agriculture

Meloidogyne javanica, the root-knot nematode, is a serious hazard to field alongside greenhouse crops, resulting in major harm and financial losses. Given the environmental and health risks linked to conventional nematicides, there is an immediate need to create and implement alternative products that are more benign for human health and the ecosystem. The current study aimed to determine mustard seed cake's nematicidal potential against second-stage juvenile (J2s) hatching and mortality. Four concentrations (250, 500, 750, and 1000 ppm) of mustard seed cake extract were applied to J2s and egg masses of M. javanica. At 1000 ppm, the highest J2s mortality (88.75) and J2 hatching inhibition (72.24 %) were seen (p = 0.002), and at 250 ppm minimum effect was observed. The gas chromatography-mass spectroscopy of mustard seed cake was done and revealed ten main bioactive compounds, among which 3-,5′-Dimethoxyacetophenone, Oleic acid, 4-Methylpentyl S-2-(dimethylamino)ethyl propylphosphonothiolate, and Erucic acid were found in higher proportion. Following that, molecular docking experiments were performed to confirm the nematicidal capabilities of mustard seed cake by examining the binding interactions between 3,5′-Dimethoxyacetophenone and erucic acid with the target protein, heat shock protein 90 (Hsp 90), in Meloidogyne javanica. The findings indicated that 3,5′-Dimethoxyacetophenone has a superior binding affinity to Hsp 90 compared to erucic acid. This indicates that mustard seed cakes may be a superior substitute for chemical nematicides in managing root-knot nematodes, enhancing plant development, and mitigating environmental threats.