Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana)
Finger millet is an ancient African-Indian crop that is resistant to many pathogens including the fungus, Fusarium graminearum. We previously reported the first isolation of putative fungal endophytes from finger millet and showed that the crude extracts of four strains had anti-Fusarium activity. H...
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MDPI AG
2016-09-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/21/9/1171 |
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| author | Walaa Kamel Mousa Adrian L. Schwan Manish N. Raizada |
| author_facet | Walaa Kamel Mousa Adrian L. Schwan Manish N. Raizada |
| author_sort | Walaa Kamel Mousa |
| collection | DOAJ |
| description | Finger millet is an ancient African-Indian crop that is resistant to many pathogens including the fungus, Fusarium graminearum. We previously reported the first isolation of putative fungal endophytes from finger millet and showed that the crude extracts of four strains had anti-Fusarium activity. However, active compounds were isolated from only one strain. The objectives of this study were to confirm the endophytic lifestyle of the three remaining anti-Fusarium isolates, to identify the major underlying antifungal compounds, and to initially characterize the mode(s) of action of each compound. Results of confocal microscopy and a plant disease assay were consistent with the three fungal strains behaving as endophytes. Using bio-assay guided fractionation and spectroscopic structural elucidation, three anti-Fusarium secondary metabolites were purified and characterized. These molecules were not previously reported to derive from fungi nor have antifungal activity. The purified antifungal compounds were: 5-hydroxy 2(3H)-benzofuranone, dehydrocostus lactone (guaianolide sesquiterpene lactone), and harpagoside (an iridoide glycoside). Light microscopy and vitality staining were used to visualize the in vitro interactions between each compound and Fusarium; the results suggested a mixed fungicidal/fungistatic mode of action. We conclude that finger millet possesses fungal endophytes that can synthesize anti-fungal compounds not previously reported as bio-fungicides against F. graminearum. |
| first_indexed | 2024-12-14T15:15:56Z |
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| id | doaj.art-5d4c1e41ce734770baf924813a9d8ea5 |
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| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-14T15:15:56Z |
| publishDate | 2016-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-5d4c1e41ce734770baf924813a9d8ea52022-12-21T22:56:19ZengMDPI AGMolecules1420-30492016-09-01219117110.3390/molecules21091171molecules21091171Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana)Walaa Kamel Mousa0Adrian L. Schwan1Manish N. Raizada2Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, CanadaDepartment of Chemistry, University of Guelph, Guelph, ON N1G 2W1, CanadaDepartment of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, CanadaFinger millet is an ancient African-Indian crop that is resistant to many pathogens including the fungus, Fusarium graminearum. We previously reported the first isolation of putative fungal endophytes from finger millet and showed that the crude extracts of four strains had anti-Fusarium activity. However, active compounds were isolated from only one strain. The objectives of this study were to confirm the endophytic lifestyle of the three remaining anti-Fusarium isolates, to identify the major underlying antifungal compounds, and to initially characterize the mode(s) of action of each compound. Results of confocal microscopy and a plant disease assay were consistent with the three fungal strains behaving as endophytes. Using bio-assay guided fractionation and spectroscopic structural elucidation, three anti-Fusarium secondary metabolites were purified and characterized. These molecules were not previously reported to derive from fungi nor have antifungal activity. The purified antifungal compounds were: 5-hydroxy 2(3H)-benzofuranone, dehydrocostus lactone (guaianolide sesquiterpene lactone), and harpagoside (an iridoide glycoside). Light microscopy and vitality staining were used to visualize the in vitro interactions between each compound and Fusarium; the results suggested a mixed fungicidal/fungistatic mode of action. We conclude that finger millet possesses fungal endophytes that can synthesize anti-fungal compounds not previously reported as bio-fungicides against F. graminearum.http://www.mdpi.com/1420-3049/21/9/1171finger milletFusarium sp.endophytefungusPenicillium sp.5-hydroxy 2(3H)-benzofuranonedehydrocostus lactoneharpagoside |
| spellingShingle | Walaa Kamel Mousa Adrian L. Schwan Manish N. Raizada Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana) Molecules finger millet Fusarium sp. endophyte fungus Penicillium sp. 5-hydroxy 2(3H)-benzofuranone dehydrocostus lactone harpagoside |
| title | Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana) |
| title_full | Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana) |
| title_fullStr | Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana) |
| title_full_unstemmed | Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana) |
| title_short | Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana) |
| title_sort | characterization of antifungal natural products isolated from endophytic fungi of finger millet eleusine coracana |
| topic | finger millet Fusarium sp. endophyte fungus Penicillium sp. 5-hydroxy 2(3H)-benzofuranone dehydrocostus lactone harpagoside |
| url | http://www.mdpi.com/1420-3049/21/9/1171 |
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