Nematicidal and antifeedant activity of ethyl acetate extracts from culture filtrates of Arabidopsis thaliana fungal endophytes

Endophytic fungi produce a diverse range of bioactive secondary metabolites with potential applications in biopesticide development. This study investigates the nematicidal and antifeedant properties of ethyl acetate extracts from endophytic fungi isolated from wild Arabidopsis thaliana populations in Spain. The extracts were tested against the plant-parasitic nematode Meloidogyne javanica, and two common insect pests, Myzus persicae and Spodoptera littoralis. Nine of the 13 extracts demonstrated significant nematicidal and/or antifeedant activity, indicating their potential as biopesticides. The active extracts were derived from six genera: Alternaria (3 isolates), Dydimella (1), Dothiora (1), Pleiochaeta (1), Penicillium (1), and Fusarium (2). Five extracts exhibited nematicidal activity above 90%, with three reducing the total number of M. javanica second-stage juveniles hatched from egg masses by 22–37%. Four extracts showed strong settling inhibition (> 70%) against M. persicae, and three exhibited feeding inhibition against S. littoralis. Chemical analysis by GC-MS and LC-MS revealed a wide array of unique secondary metabolites in the active extracts, reflecting substantial chemical diversity, regardless of the fungal origin. This study highlights the potential of fungal endophytes from A. thaliana as sources of novel biopesticides, paving the way for future research focused on harnessing these fungi for biopesticide development.