3-Furoic Acid from Sea-Derived Aspergillus luchuensis Hy-6 as a Valuable Lead Compound against Plant-Parasitic Nematodes in Cucumber

Root-knot nematodes pose a significant threat to crop growth and yield, thereby impacting global food security. Here, the sea-derived Aspergillus luchuensis hy-6 was identified as a producer of 3-furoic acid by liquid chromatography–mass spectrometry. Low doses of 3-furoic acid, an acidic compound with strong nematicidal activity, can reduce the motility, lifespan, and egg hatchability of nematodes in a dose-dependent manner. Additionally, 3-furoic acid was found to affect the chemotaxis of Meloidogyne incognita toward cucumber by decreasing the root’s attractive activity to the nematodes. Metabolomic analyses indicated that the functional abnormalities in lipid metabolism may represent a critical molecular mechanism underlying severe metabolic dysfunction. Importantly, a significant enhancement in control efficacy was achieved through a simple structural modification, particularly with pent-4-en-1-yl furan-3-carboxylate (A1), which was superior to that of 3-furoic acid. These findings validated the potential of 3-furoic acid as a promising lead in the development of eco-friendly nematicides.