Endophyte-infected Perennial Ryegrass Research Articles

Isolation and Structure Elucidation of Lolitrem A, a Tremorgenic Mycotoxin from Perennial Ryegrass Infected with Acremonium lolii

Lolitrem A, the second most abundant minor lolitrem in endophyte-infected perennial ryegrass, has been isolated and its structure determined by mass spectrometry and one- and two-dimensional NMR spectroscopy. Lolitrem A, which other workers have suggested to be 7α-hydroxylolitrem B, was found to be an inseparable mixture of the 44R and 44S isomers of 44,45-epoxylolitrem C. An assignment of the methyl group proton and carbon resonances of lolitrem B is also reported. The intensity and time course of the tremorgenic activity of lolitrem A in mice were identical to that of lolitrem B.

Analysis of endophyte toxins: fescue and other grasses toxic to livestock.

Research on livestock toxicoses caused by Acremonium (endophyte)-infected grasses strongly implicate the ergopeptine alkaloids with A. coenophialum-infected fescue and paxilline and the lolitrem alkaloids with A. lolii-infected perennial ryegrass as the causative agents. Isolation, identification, and detection of these toxins involves extraction with appropriate solvents, clean-up procedures, and chromatographic methods with known standards. Thin-layer, high-performance liquid and gas chromatography along with ultraviolet and mass spectrometric (i.e., electron impact, chemical ionization, tandem mass) characterizations have been reported. These methods have varying degrees of success depending on the matrix from which the alkaloids have been extracted. Ergovaline is the primary ergopeptine alkaloid isolated from cultures of A. coenophialum and also from infected fescue grass and seeds toxic to livestock. Other compounds isolated from the endophyte-infected fescue include: lysergic acid amide (ergine), the clavine class of ergot alkaloids (chanoclavine I, agroclavine, elymoclavine, penniclavine), the pyrrolizidine alkaloids (N-formylloline, N-acetylloline, N-methyloline, N-acetylnorloline), and the unique pyrrolopyrazine alkaloid peramine. The loline alkaloids and peramine have been more associated with the insect-deterrent properties of the endophyte-infected fescue than with livestock toxicoses. Also, both peramine and the ergopeptine alkaloids (ergovaline, ergotamine) have been isolated from A. lolii-infected perennial ryegrass. More recently, paxilline and lolitrem B have been detected in laboratory cultures of A. coenophialum isolated from tall fescue. The ergot alkaloids in endophyte-infected perennial ryegrass may be more related to decreased animal productivity (weight gains, reproduction problems), whereas the lolitrems cause the staggers syndrome. The detection, isolation, identification, and analyses of these compounds from Acremonium-infected grasses is presented.

The effect of glyphosate, paraquat and paclobutrazol on lolitrem B levels in endophyte-infected perennial ryegrass

Two herbicides (glyphosate and paraquat) and a plant growth regulator (paclobutrazol) were applied to endophyteinfected (Acremonium lolii) perennial ryegrass swards. Subsamples of these swards were then chemically analysed at intervals up to 28 days later for lolitrem B, the compound responsible for perennial ryegrass staggers in domestic livestock. Glyphosate and paclobutrazol had no effect on lolitrem B concentrations. Paraquat applications decreased lolitrem B concentrations in the herbage. Because none of the chemicals tested increased the concentration of lolitrem B in the herbage, they are unlikely to be directly implicated in perennial ryegrass staggers in grazing animals.

Enhanced Resistance to Three Species of Aphids (Homoptera: Aphididae) in Acremonium Endophyte-Infected Turfgrasses

Association of Acremonium endophytes with enhanced resistance to insects in various turfgrasses was studied using three species of aphids; greenbug, Schizaphis graminum (Rondani); bird cherry-oat aphid, Rhopalosiphum padi (L.); and yellow sugarcane aphid, Sipha flava (Forbes). Choice and no-choice tests were used to test resistance in three to four genotypes each of endophyte-infected and endophyte-free perennial ryegrass, Lolium perenne L.; tall fescue, Festuca arundinacea Schreb.; and three species of fine fescues: hard fescue, F. longifolia Thuill; Chewings fescue, F. rubra L. subsp. commutate Gaud.; and blue fescue, F. glauca Lam. Feeding deterrence and antibiosis were significant in endophyte-infected tall fescue for all turfgrass genotypes and aphids tested, with no aphids surviving after 3 d on infected tall fescue. Feeding deterrence and antibiosis to greenbug and yellow sugarcane aphid were significant in endophyte-infected perennial ryegrass with all genotypes tested. None survived on endophyte-infected perennial ryegrass after 72 h. Resistance to bird cherry-oat aphid was dependent on concentration of endophyte hyphae in the host, with significant resistance observed in genotypes with high concentrations. Resistance in endophyte-infected fine-leaved fescues varied with insect and grass species. Preference was generally not significantly affected, but dramatic differences in survival were found in ‘Ensylva’ strong creeping red fescue, blue fescues, Chewings fescues, and hard fescues. Endophyte-enhanced resistance to insects varies between species of grasses and insects, and within species of grasses, suggesting that each endophyte or endophyte-host genotype complex should be evaluated individually.

Argentine stem weevil damage to endophyte-infected perennial ryegrass planted in association with endophyte-free ryegrass and poa

Argentine stem weevil damage to endophyte-infected perennial ryegrass planted in association with endophyte-free ryegrass and poa

Reproductive performance of CD-1 mice fed diets containing endophyte-infected perennial ryegrass seed through continuous breeding

Abstract This study was undertaken to further determine the sensitivity of the mouse to a diet containing endophyte-infected (Acremonium lolii) perennial ryegrass (Lolium perenne L.) seed. The degree to which the mouse is affected by the endophyte will determine its value as a bioassay to study ryegrass toxicity in livestock. The focus of this study was to determine the effects of the endophyte on the reproductive performance of mice (Mus musculus) using a continuous breeding protocol for three parturitions. Thirty-six CD-1 mice were randomly assigned to one of three dietary treatments and housed separately by sex for 42 days before pairing. The diets contained 50% Purina rodent chow (w/w) and: (1) 50% endophyte-infected perennial ryegrass seed; (2) 25% infected seed and 25% un-infected seed; or (3) 50% un-infected seed. The intake for Diet 2 and Diet 3 was limited to the average daily intake of Diet 1. The mice were allowed to cohabit through three parturitions. Litter parameters assessed included dam we...

Effect of endophyte-infected perennial ryegrass seed diets on growth and reproduction in mice

Abstract This study was undertaken to determine whether mice could be used as a small animal bioassay to study the effects of endophyte (Acremonium lolii)-infected perennial ryegrass (Lolium perenne) on growth and reproduction. Seventy-two CD-1 mice (36 males and 36 females) were randomly assigned to one of six dietary treatments and housed separately for 56 days before being allowed to cohabit for 49 days. The diets included ad libitum feeding of rations containing 50% (v/w) Purina Rodent Chow plus 50, 37.5, 25, or 0% infected ‘Grasslands Nui’ perennial ryegrass seed, and rations containing either 50% un-infected seed or 100% rodent chow restricted to the average daily intake of the 50% infected diet (pair-fed). The 37.5 and 25% diets were made to 100% with un-infected seeds. Mice fed the 50% infected seed diet did not consume less food but gained significantly less weight (P < 0.05) than the other treatment mice during the 56-day trial. All mice fed ryegrass seed gained less than the mice fed restricted...

Increase in the proportion of endophyte-infected perennial ryegrass plants in overdrilled pastures

Abstract “Low” and “high” endophyte (Acremonium lolii Latch, Christensen and Samuels) seed lines of ‘Grasslands Ariki‘ (Lolium(multiflorum x perenne) × perenne) and ‘Grasslands Nui’ ryegrasses (Lolium perenne L.) were overdrilled into herbicided old pasture on a Lismore stony Silt loam under dryland or irrigated conditions. In the 3 years after sowing, the proportion of endophytic plants in the “low” endophyt:e pasture increased to 67% for Nui and 83% for Ariki, from 3% infection measured in both seedlines. The most significant proportion of this increase occurred over the first 10 months. It is suggested that Argentine stem weeVil (Listronotus bonariensis Kuschel) did not play a large part in the increase in endophyte-infected plants since larval numbers were low. Endophyte infection may confer a competitive advantage to ryegrass plants.

Detection of ergopeptine alkaloids in endophyte-infected perennial ryegrass by tandem mass spectrometry

Abstract Extract Madam:— There is currently considerable interest in the effects of the ryegrass endophyte upon animal performance and pasture production. Recent research has resulted in the isolation of the lolitrem neurotoxins (3) and the Argentine stem weevil feeding deterrent peramine (6) from endophyte infected perennial ryegrass. We now wish to report the occurrence in endophyte infected ryegrass of a third group of bioactive compounds; the ergopeptine alkaloids which have been detected in ryegrass stubble using tandem mass spectrometry.