<i>Neotyphodium</i>Research and Application in Australia

Reed, K. F. M.; Scrivener, CJ; Rainsford, K. A.; Walker, L. V.

doi:10.1002/9780470384916.ch1d

Cited by 8 publications

(9 citation statements)

References 5 publications

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“…In contrast to perennial ryegrass, tall fescue sold for pastures in Australia has largely been free of endophyte (N. coenophialum) (Easton et al 1994;Reed et al 2005b), although this has changed in recent years with the development of selected endophytes. Endophyte-infected tall fescue can be found naturalised in Australia.…”

Section: Endophyte and Tall Fescuementioning

confidence: 99%

“…Symptoms include ill health (ryegrass staggers, heat stress), loss of productivity, and mortality. In some years, there are widespread outbreaks of severe perennial ryegrass toxicosis (Reed et al 2005b(Reed et al , 2011. For example, in 2002, almost 100 000 livestock died, mainly sheep, with an estimated similar loss in winter because of the summer-autumn event.…”

Section: Introductionmentioning

confidence: 99%

“…These major events are sporadic, with three such epidemics since 1985. Ryegrass staggers in sheep can be observed every year in some regions (Reed et al 2005b), while subclinical losses are also likely in most years and are widespread (Valentine et al 1993b;Foot et al 1994;Lean 2001;Reed et al 2005a). In an economic analysis in 2006, Sackett and Francis (2006) conservatively estimated that perennial ryegrass toxicosis was causing financial losses of AU $72 million year -1 for Australian sheep and beef producers, with a more recent assessment in 2012 placing this at $100 million year -1 (J. Webb Ware, unpubl.…”

Section: Introductionmentioning

confidence: 99%

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Agronomic advantages conferred by endophyte infection of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) in Australia

Hume

Sewell²

2014

Crop Pasture Sci.

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Perennial ryegrass and tall fescue are key grasses of sown pastures in the high-rainfall zone of south-eastern Australia. Ryegrass in naturalised pastures, and in sown seed, is widely infected with Neotyphodium fungal endophytes, with toxic endophyte strains occasionally causing toxicosis in livestock. Endophyte infection is also beneficial in sown grasslands, assisting ryegrass hosts to overcome biotic stresses, and tall fescue hosts to overcome biotic and abiotic stresses. We review the literature for Australia and present new data, to examine the agronomic effects of endophyte. Frequency of endophyte infection in old, perennial ryegrass pastures and ecotype-based cultivars is high and, in all pastures, increases with time, providing evidence for endophyte-infected plants having an agronomic advantage over endophytefree plants. Within a cultivar, agronomic field experiments have compared endophyte-infected with endophyte-free swards. Endophyte significantly improved ryegrass establishment in seven of 19 measurements taken from 12 trials. In mature ryegrass pastures, over half of the experiments found advantages to endophyte infection. Tall fescues infected with a selected endophyte ('AR542') had improved agronomic performance relative to endophyte-free in a majority of experiments, and on occasions, the endophyte was essential for tall fescue persistence. Cultivar Â endophyte interactions occurred but were inconsistent. In high-stress environments, endophyte was more important for agronomic performance than difference between cultivars. The relative importance of cultivar and endophyte is discussed, with elite cultivars that are adapted to the region and are infected with elite endophytes being the best avenue to capture the benefits and minimise detrimental endophyte effects on livestock. The major drivers are likely to be insect pests and drought, but evidence is limited.

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Section: Endophyte and Tall Fescuementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Agronomic advantages conferred by endophyte infection of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) in Australia

Hume

Sewell²

2014

Crop Pasture Sci.

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“…The impaired motor coordination produced by lolitrem B results in major animal production and management problems as well as significant livestock losses. In 2002, a major outbreak of ryegrass staggers in Australia resulted in the death of tens of thousands of sheep and hundreds of cattle (Reed et al, 2005), and this disease has been estimated to cost NZ$100 million per annum in lost animal production. The molecular target for lolitrem B in producing ryegrass staggers is unknown.…”

mentioning

confidence: 99%

The Molecular Mechanism of “Ryegrass Staggers,” a Neurological Disorder of K⁺ Channels

Imlach

Finch

Dunlop

et al. 2008

J Pharmacol Exp Ther

103

115

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"Ryegrass staggers" is a neurological condition of unknown mechanism that impairs motor function in livestock. It is caused by infection of perennial ryegrass pastures by an endophytic fungus that produces neurotoxins, predominantly the indolediterpenoid compound lolitrem B. Animals grazing on such pastures develop uncontrollable tremors and become uncoordinated in their movement. Lolitrem B and the structurally related tremor inducer paxilline both act as potent large conductance calcium-activated potassium (BK) channel inhibitors. Using patch clamping, we show that their different apparent affinities correlate with their toxicity in vivo. To investigate whether the motor function deficits produced by lolitrem B and paxilline are due to inhibition of BK ion channels, their ability to induce tremor and ataxia in mice deficient in this ion channel (Kcnma1 Ϫ/Ϫ ) was examined. Our results show that mice lacking Kcnma1 are unaffected by these neurotoxins. Furthermore, doses of these substances known to be lethal to wild-type mice had no effect on Kcnma1 Ϫ/Ϫ mice. These studies reveal the BK channel as the molecular target for the major components of the motor impairments induced by ryegrass neurotoxins. Unexpectedly, when the response to lolitrem B was examined in mice lacking the ␤4 BK channel accessory subunit (Kcnmb4 Ϫ/Ϫ ), only low-level ataxia was observed. Our study therefore reveals a new role for the accessory BK ␤4 subunit in motor control. The ␤4 subunit could be considered as a potential target for treatment of ataxic conditions in animals and in humans.

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“…This is a low proportion, even given the difficult nutritional conditions and low BW of ewes, which were below the optimum 6 . An increased proportion of non‐pregnant ewes has been reported during severe outbreaks of perennial ryegrass toxicosis, and so the severe ryegrass staggers that occurred during and after mating may explain this observation 7,8 . Significantly more ewes in group 2 were pregnant compared with the ewes in groups 1 and 3 (both P < 0.01).…”

mentioning

confidence: 97%

Long‐acting moxidectin for the control of trichostrongylid infections of sheep in south‐eastern Australia

Larsen

Anderson

Preshaw³

2009

Aust Veterinary J

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NeotyphodiumResearch and Application in Australia

Cited by 8 publications

References 5 publications

Agronomic advantages conferred by endophyte infection of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) in Australia

Agronomic advantages conferred by endophyte infection of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) in Australia

The Molecular Mechanism of “Ryegrass Staggers,” a Neurological Disorder of K⁺ Channels

Long‐acting moxidectin for the control of trichostrongylid infections of sheep in south‐eastern Australia

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NeotyphodiumResearch and Application in Australia

Cited by 8 publications

References 5 publications

Agronomic advantages conferred by endophyte infection of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) in Australia

Agronomic advantages conferred by endophyte infection of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) in Australia

The Molecular Mechanism of “Ryegrass Staggers,” a Neurological Disorder of K+ Channels

Long‐acting moxidectin for the control of trichostrongylid infections of sheep in south‐eastern Australia

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The Molecular Mechanism of “Ryegrass Staggers,” a Neurological Disorder of K⁺ Channels