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An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products.

Mousa WK, Schwan A, Davidson J, Strange P, Liu H, Zhou T, Auzanneau FI, Raizada MN - Front Microbiol (2015)

Bottom Line: We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products.This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products.Application of these natural chemicals to solve real world problems will require further validation.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Agriculture, University of Guelph Guelph, ON, Canada ; Department of Pharmacognosy, Mansoura University Mansoura, Egypt.

ABSTRACT
Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.

No MeSH data available.


Related in: MedlinePlus

Testing the pathogenicity of the putative endophyte WF4 on finger millet. (A) Representative pictures showing the effect of the known pathogen Alternaria alternata on finger millet seedlings (negative control). (B) Representative pictures showing the effect of buffer on finger millet seedlings (positive control). (C) Representative pictures showing the effect of the fungus WF4 on finger millet seedlings.
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Figure 2: Testing the pathogenicity of the putative endophyte WF4 on finger millet. (A) Representative pictures showing the effect of the known pathogen Alternaria alternata on finger millet seedlings (negative control). (B) Representative pictures showing the effect of buffer on finger millet seedlings (positive control). (C) Representative pictures showing the effect of the fungus WF4 on finger millet seedlings.

Mentions: Finger millet seedlings were incubated with WF4 or with Alternaria alternata, a known pathogen of finger millet (Kumar, 2010). The seedlings incubated with A. alternata developed characteristic disease symptoms including reduction in plant length, black roots and leaf spots (Figure 2A), compared to the healthy buffer control (Figure 2B). In comparison, there were no disease symptoms observed in the seedlings challenged with WF4 (Figure 2C).


An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products.

Mousa WK, Schwan A, Davidson J, Strange P, Liu H, Zhou T, Auzanneau FI, Raizada MN - Front Microbiol (2015)

Testing the pathogenicity of the putative endophyte WF4 on finger millet. (A) Representative pictures showing the effect of the known pathogen Alternaria alternata on finger millet seedlings (negative control). (B) Representative pictures showing the effect of buffer on finger millet seedlings (positive control). (C) Representative pictures showing the effect of the fungus WF4 on finger millet seedlings.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4612689&req=5

Figure 2: Testing the pathogenicity of the putative endophyte WF4 on finger millet. (A) Representative pictures showing the effect of the known pathogen Alternaria alternata on finger millet seedlings (negative control). (B) Representative pictures showing the effect of buffer on finger millet seedlings (positive control). (C) Representative pictures showing the effect of the fungus WF4 on finger millet seedlings.
Mentions: Finger millet seedlings were incubated with WF4 or with Alternaria alternata, a known pathogen of finger millet (Kumar, 2010). The seedlings incubated with A. alternata developed characteristic disease symptoms including reduction in plant length, black roots and leaf spots (Figure 2A), compared to the healthy buffer control (Figure 2B). In comparison, there were no disease symptoms observed in the seedlings challenged with WF4 (Figure 2C).

Bottom Line: We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products.This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products.Application of these natural chemicals to solve real world problems will require further validation.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Agriculture, University of Guelph Guelph, ON, Canada ; Department of Pharmacognosy, Mansoura University Mansoura, Egypt.

ABSTRACT
Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.

No MeSH data available.


Related in: MedlinePlus