Antifeedant, antifungal and nematicidal compounds from the endophyte Stemphylium solani isolated from wormwood
The continuous search for natural product-based biopesticides from fungi isolated from untapped sources is an efective tool. In this study, we studied a pre-selected fungal endophyte, isolate Aa22, from the medicinal plant Artemisia absinthium, along with the antifungal, insect antifeedant and nemat...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de La Laguna (ULL) |
| Repositorio: | RIULL. Repositorio Institucional de la Universidad de La Laguna |
| OAI Identifier: | oai:riull.ull.es:915/41455 |
| Acceso en línea: | http://riull.ull.es/xmlui/handle/915/41455 |
| Access Level: | acceso abierto |
| Palabra clave: | Antifeedant antifungal nematicidal compounds endophyte Stemphylium solani |
| Sumario: | The continuous search for natural product-based biopesticides from fungi isolated from untapped sources is an efective tool. In this study, we studied a pre-selected fungal endophyte, isolate Aa22, from the medicinal plant Artemisia absinthium, along with the antifungal, insect antifeedant and nematicidal compounds present in the extract. The endophyte Aa22 was identifed as Stemphylium solani by molecular analysis. The antifungal activity was tested by broth microdilution against Fusarium solani, F. oxysporum, F. moniliforme and Botrytis cinerea, the insect antifeedant by choice bioassays against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi and the in vitro mortality against the root-knot nematode Meloiydogyne javanica. The structures of bioactive compounds were determined on the basis of 1D and 2D NMR spectroscopy and mass spectrometry. The ethyl acetate extract obtained from the solid rice fermentation showed mycelial growth inhibition of fungal pathogens (EC50 0.08–0.31 mg/mL), was antifeedant to M. persicae (99%) and nematicidal (68% mortality). A bioguided fractionation led to the isolation of the new compound stempholone A (1), and the known stempholone B (2) and stemphol (3). These compounds exhibited antifeedant (EC50 0.50 mg/mL), antifungal (EC50 0.02–0.43 mg/L) and nematicidal (MLD 0.5 mg/mL) activities. The extract activities can be explained by 3 (antifungal), 1–3 (antifeedant) and 1 (nematicidal). Phytotoxicity tests on Lolium perenne and Lactuca sativa showed that the extract and 1 increased L. sativa root growth (121–130%) and 1 reduced L. perenne growth (48–49%). These results highlight the potential of the endophytic fungi Aa22 as biotechnological source of natural product-based biopesticides. |
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