Biosynthesis of Ergot and Loline Alkaloids

Schardl, Christopher L.; Panaccione, Daniel G.

doi:10.1002/9780470384916.ch2

Cited by 8 publications

(4 citation statements)

References 43 publications

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“…1) but not the spring. Total ergot alkaloids were determined by ELISA, which detects compounds known to be precursors in ergovaline synthesis (Schardl and Panaccione, 2005). The ELISA method may also be detecting derivative products of ergovaline breakdown that could have occurred over the previous winter (Kallenbach et al, 2003).…”

Section: Resultsmentioning

confidence: 99%

Seasonal Fluctuation of Ergovaline and Total Ergot Alkaloid Concentrations in Tall Fescue Regrowth

et al. 2011

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Common cultivars of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort = Lolium arundinaceum (Schreb.) Darbysh.] host a fungal endophyte that produces ergot alkaloids. These alkaloids are linked to fescue toxicosis, a serious livestock disorder in the United States. This study was conducted to determine how ergot alkaloid concentrations fluctuate throughout the growing season in tall fescue regrowth. In 2005, plots were established in pastures of endophyte-infected tall fescue growing in Missouri, Georgia, and South Carolina. Each month of the growing season, plots were clipped and forage allowed to regrow; regrowth was sampled from April through October 2006 and analyzed for ergovaline and total ergot alkaloid concentrations. At all three sites, ergovaline concentration was lowest during the spring, increasing slightly through the summer months and then sharply in the early autumn. This pattern of ergovaline fluctuation did not mimic data published from experiments in which tall fescue was grazed or was allowed to grow without defoliation. Total ergot alkaloid concentration followed a bimodal curve, with highest concentration in the spring and fall and lowest concentration in the summer. We conclude that common cultivars of endophyte-infected tall fescue should be regarded as highly toxic in the autumn and less toxic in the summer, even if pastures are clipped. We also conclude that the toxicity potential of tall fescue regrowth in the spring depends on which ergot alkaloids prove most responsible for fescue toxicosis.

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Section: Resultsmentioning

confidence: 99%

Seasonal Fluctuation of Ergovaline and Total Ergot Alkaloid Concentrations in Tall Fescue Regrowth

et al. 2011

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“…1), but not April. One possible explanation could be that total ergot alkaloid concentrations were determined by ELISA, which detects compounds known to be precursors in ergovaline synthesis (Schardl and Panaccione, 2005). It should be remembered that ergovaline concentration, determined by HPLC, does not always correspond to total ergot alkaloid concentration, determined by ELISA (Roberts et al, 2014).…”

Section: Total Ergot Alkaloids Vs Ergovaline Concentrationsmentioning

confidence: 99%

Vertical Distribution of Ergot Alkaloids in the Vegetative Canopy of Tall Fescue

et al. 2018

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Ergot alkaloids are toxins produced by Epichloë coenophiala (Morgan‐Jones & W. Gams) C.W. Bacon & Schardl, a fungal endophyte that infects tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] and causes fescue toxicosis in livestock. Previous studies have reported the distribution of ergovaline among anatomical parts during reproductive development. This study was conducted to determine the vertical distribution of ergovaline and total ergot alkaloids throughout the vegetative canopy of tall fescue. Between October 2012 and April 2014, whole tillers were harvested four times from a stand of Epichloë‐infected ‘Kentucky 31’ tall fescue near Alton, MO. Harvests occurred in April before boot stage and in October before killing frost. Tillers were sliced into four segments: 0 to 5, 5 to 10, 10 to 15, and >15 cm, where 0 cm was the soil level, and >15 cm was the top of the canopy. Segments were analyzed for ergovaline and total ergot alkaloids. For tillers harvested in April, ergovaline concentration averaged 272 μg kg−1 dry matter (DM) in the 0‐ to 5‐cm segment and decreased linearly upward through the canopy. In October, break‐point regression indicated that ergovaline concentration averaged 1121 μg kg−1 DM in the 0‐ to 5‐cm segment and ≥70% less above 5 cm. Total ergot alkaloid distribution patterns resembled ergovaline distribution in October; total ergot alkaloids averaged 2585 μg kg−1 DM in the 0‐ to 5‐cm segment and >60% less in the upper portion of the canopy. These findings should encourage field advisors to consider variation of toxicity within the canopy of tall fescue when formulating grazing recommendations.

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“…These are converted to dimethylallyl-tryptophan (DMAT) by DMAT synthase, in what is probably the limiting step in ergot alkaloid formation (64). N-methylation and C-oxidation of DMAT leads to formation of a diene, which is then epoxidized, resulting in spontaneous cyclization of the C-ring and release of an α-carboxyl group, yielding chanoclavine I; the first of the clavines (66). The cyclization of the D-ring of chanoclavine I is catalyzed sequentially by chanoclavine I dehydrogenase, a flavine-dependent oxidoreductase, then a reductase, to produce the tetracyclic clavine alkaloid, agroclavine (67).…”

Section: Synthesis and Structurementioning

confidence: 99%

Endophyte Infected Tall Fescue: Plant Symbiosis to Animal Toxicosis

2021

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Endophyte-infected fescue is a major cool season forage used for livestock production in the United States and through other areas of the world. A unique aspect of this forage resource is the symbiotic relationship with an endophytic fungus (Epichloë coenophiala) that has detrimental impact on herbivores due to toxic ergot alkaloids. Research over the past 50 years has unveiled details regarding this symbiotic relationship. This review focuses on the origin of tall fescue in the United States and the consequences of its wide-spread utilization as a livestock forage, along with the discovery and toxicodynamics of ergot alkaloids produced by E. coenophiala. The majority of past ergot alkaloid research has focused on observing phenotypic changes that occur in livestock affected by ergot alkaloids, but recent investigation of the metabolome, transcriptome, and proteome have shown that fescue toxicity-related illnesses are much more complex than previous research suggests.

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Biosynthesis of Ergot and Loline Alkaloids

Cited by 8 publications

References 43 publications

Seasonal Fluctuation of Ergovaline and Total Ergot Alkaloid Concentrations in Tall Fescue Regrowth

Seasonal Fluctuation of Ergovaline and Total Ergot Alkaloid Concentrations in Tall Fescue Regrowth

Vertical Distribution of Ergot Alkaloids in the Vegetative Canopy of Tall Fescue

Endophyte Infected Tall Fescue: Plant Symbiosis to Animal Toxicosis

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