Physiological Responses of Rats Fed Loline and Ergot Alkaloids from Endophyte-Infected Tall Fescue

Jackson, James; Varney, D. R.; Petroski, Richard J.; Powell, Richard G.; Bush, Lowell P.; Siegel, Malcolm R.; Hemken, R.W.; Zavos, Panayiotis M.

doi:10.3109/01480549609002198

Cited by 13 publications

(11 citation statements)

References 16 publications

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“…However, an unusual ether bridge between C-2 and C-7, a completely saturated pyrrolizidine ring, and an amino group at C-1 are structural features distinguishing the lolines from the necines (Bush et al, 1993;Schardl et al, 2007). Unlike the necines, which have potent anti-mammalian activities (Hartmann and Witte, 1995;Pelser et al, 2005), notably strong hepatotoxicity and carcinogenicity (Fu et al, 2004), lolines lack significant mammalian toxicity (Jackson et al, 1996). The potent insecticidal activity of the lolines and the lack of anti-mammalian activity have generated interest in these compounds as plant protectants.…”

Section: Introductionmentioning

confidence: 96%

Role of the LolP cytochrome P450 monooxygenase in loline alkaloid biosynthesis

Spiering

Faulkner

Zhang

et al. 2008

Fungal Genetics and Biology

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Section: Introductionmentioning

confidence: 96%

Role of the LolP cytochrome P450 monooxygenase in loline alkaloid biosynthesis

Spiering

Faulkner

Zhang

et al. 2008

Fungal Genetics and Biology

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“…Some studies report negative effects, such as decreases in population density (Coley et al, 1995), increased toxicity-induced mortality (Conover, 1998) and suppression of reproduction and growth (Jackson et al, 1996; Durham and Tannenbaum, 1998; Fortier et al, 2000; Conover, 2003), while others have found no effects at all (Barger and Tannenbaum, 1998; Saari et al, 2010). Thus, the effects of endophytic fungi on herbivores may be dose-dependent and may vary between grass, fungi and herbivore species.…”

Section: Introductionmentioning

confidence: 99%

Silicon, endophytes and secondary metabolites as grass defenses against mammalian herbivores

Huitu¹,

Forbes²,

Helander

et al. 2014

Front. Plant Sci.

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Grasses have been considered to primarily employ tolerance in lieu of defense in mitigating damage caused by herbivory. Yet a number of mechanisms have been identified in grasses, which may deter feeding by grazers. These include enhanced silicon uptake, hosting of toxin-producing endophytic fungi and induction of secondary metabolites. While these mechanisms have been individually studied, their synergistic responses to grazing, as well as their effects on grazers, are poorly known. A field experiment was carried out in 5 × 5 m outdoor enclosures to quantify phytochemical changes of either endophyte-infected (E+) or endophyte-free (E-) meadow fescue (Schedonorus pratensis) in response to medium intensity (corresponding with densities of ca. 1200 voles/ha for 5 weeks during 3 months) or heavy intensity (ca. 1200 voles/ha for 8 weeks during 3 months) grazing by a mammalian herbivore, the field vole (Microtus agrestis). A laboratory experiment was then conducted to evaluate the effects of endophyte infection status and grazing history of the grass diet on vole performance. As predicted, grazing increased foliar silicon content, by up to 13%. Grazing also increased foliar levels of phosphorous and several phenolic compounds, most notably those of the flavonols isorhamnetin-diglycoside and rhamnetin derivative. Silicon concentrations were consistently circa 16% higher in E+ grasses than in E-grasses, at all levels of grazing. Similarly, concentrations of chlorogenic acid derivative were found to be consistently higher in E+ than in E- grasses. Female voles maintained on heavily grazed grasses suffered higher mortality rates in the laboratory than female voles fed ungrazed grass, regardless of endophyte infection status. Our results conclusively demonstrate that, in addition to tolerance, grasses employ multi-tiered, effective defenses against mammalian grazers.

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“…7). The ecological significance of lolines has been linked to their anti-invertebrate and feeding deterrent activities, while they seem to be weakly or nontoxic to mammalian herbivores [53,54]. Yet the production of lolines by the endophytic fungi in plant is likely to be substantial, approaching up to 2% of the plant dry mass [51b].…”

Section: Studies In Natural Products Chemistrymentioning

confidence: 99%