scholarly journals Grass-endophyte interactions: a note on the role of monosaccharide transport in the Neotyphodium lolii-Lolium perenne symbiosis

2012 ◽  
Vol 196 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Susanne Rasmussen ◽  
Qianhe Liu ◽  
Anthony J. Parsons ◽  
Hong Xue ◽  
Bruce Sinclair ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Grass Endophyte ◽  
Neotyphodium Lolii ◽  
Monosaccharide Transport

scholarly journals High nutrient supply and carbohydrate content reduce endophyte and alkaloid concentration

2007 ◽  
Vol 13 ◽  
pp. 135-138
Author(s):  
S. Rasmussen ◽  
A.J. Parsons ◽  
Q. Liu ◽  
H. Xue ◽  
J.A. Newman
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Fungal Endophytes ◽  
Carbohydrate Content ◽  
Nutrient Inputs ◽  
High Sugar ◽  
Neotyphodium Lolii ◽  
Grassland Ecosystems ◽  
Leaf Tissues

Two controlled environment experiments were performed to test the effects of nitrogen, phosphorus and carbohydrates on endophyte (Neotyphodium lolii) and alkaloid concentrations in ryegrass (Lolium perenne). Three perennial ryegrass cultivars ('high sugar grasses' AberDove and AberDart; control Fennema) that differ in carbohydrate content were infected with three strains of N. lolii (common strain, CS; AR1; AR37). Infected and uninfected plants were grown under high (9 mM) and low (2.25 mM) nitrogen (AberDove, Fennema; CS, AR1, AR37) or under high (2 mM KH2PO4) and low (0.05 mM KH2PO4) phosphorus (AberDart, Fennema; CS, AR1). Quantitative realtime Polymerase Chain Reaction (qPCR) was used to estimate endophyte concentrations in harvested leaf tissues. High N and P supply as well as high carbohydrate content of the host grass reduced endophyte concentrations. Alkaloid production was also reduced under both increased N supply and in the high sugar cultivar, and was linearly related to endophyte concentration (except ergovaline). The results stress the need for wider quantification of fungal endophytes in the grassland/ foliar endophyte context, and have implications for how introducing new cultivars, novel endophytes, or increasing nutrient inputs, affect the role of endophytes in grassland ecosystems. Keywords: Neotyphodium lolii, foliar endophyte, Lolium perenne, perennial ryegrass, qPCR, high sugar ryegrass, nitrogen, phosphate, carbohydrate, AR1, AR37, alkaloids

scholarly journals The role of cAMP signalling in the symbiosis between Epichloe festucae and Lolium perenne

2007 ◽  
Vol 13 ◽  
pp. 457-459
Author(s):  
C.R. Voisey ◽  
M.J. Christensen ◽  
R.D. Johnson ◽  
L.J. Johnson ◽  
A.K. Khan ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Lolium Perenne ◽  
Large Scale ◽  
Target Genes ◽  
Targeted Disruption ◽  
Camp Signalling ◽  
Neotyphodium Lolii ◽  
Signalling Network ◽  
Signalling Cascade

In fungal pathogenesis the cAMP signalling cascade is usually essential for virulence. Deletion of the adenylate cyclase gene, the enzyme that synthesises cAMP, often results in an attenuated or avirulent phenotype. Our aim was to identify the signalling mechanisms regulating colonisation of perennial ryegrass (Lolium perenne) by the fungal symbiont Epichloë festucae Fl1. We have identified genes from several signalling networks, and here report on the outcomes of targeted disruption of the E. festucae Fl1 adenylate cyclase gene (acyA). A dual genome (endophyte/ ryegrass) Affymetrix GeneChip® has been synthesised and we are undertaking large scale transcript profiling of the L. perenne/ E. festucae ΔacyA symbiotum to identify target genes regulated by the endophyte cAMP signalling network. Keywords: cAMP, adenylate cyclase, acyA, Neotyphodium lolii, Epichloë festucae, symbiosis, Affymetrix GeneChip

Incidence of ryegrass endophyte (Neotyphodium lolii) and diversity of associated alkaloid concentrations among naturalised populations of perennial ryegrass (Lolium perenne L.)

2000 ◽  
Vol 51 (5) ◽  
pp. 569 ◽  
Author(s):  
K. F. M. Reed ◽  
A. Leonforte ◽  
P. J. Cunningham ◽  
J. R. Walsh ◽  
D. I. Allen ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Critical Level ◽  
Clinical Symptoms ◽  
Lolium Perenne L ◽  
Grass Endophyte ◽  
Neotyphodium Lolii ◽  
The Mean ◽  
Lolitrem B ◽  
Mutualistic Association

The mutualistic association between perennial ryegrass (Lolium perenne L.) and the ryegrass endophyte Neotyphodium lolii (Latch, Christensen and Samuels) Glenn, Bacon and Hanlin, previously assigned to the genus Acremonium, is known to have a major impact on pasture and animal production. The perennial ryegrass ecotypes Victorian and Kangaroo Valley are the most widely sown varieties of grass in Australian pasture. The incidence of ryegrass endophyte (N. lolii) in these ecotypes, and the production of alkaloids associated with theryegrass endophyte, are largely unexplored. Fifty-six populations of Victorian and 45 of Kangaroo Valley were sampled from old pasture within the recognised zones of naturalisation of both ecotypes. All of the 101 populations examined were infected with ryegrass endophyte. The mean ryegrass endophyte (N. lolii) frequency for plants within the populations of the Victorian and Kangaroo Valley ecotypes was 88% and 93%, respectively. Alkaloid concentrations were determined from infected plants for 39 Kangaroo Valley populations and, in a separate study, for 24 Victorian populations. Ergovaline concentration was above the critical level of 0.4 mg/kg (above which clinical symptoms are observed) for 10% of the Kangaroo Valley populations and 17% of the Victorian populations. For lolitrem B, all Victorian populations were below the critical level of 1.8 mg/kg, but 28% of the Kangaroo Valley populations had mean concentrations above the critical level, 1.8 mg/kg. Concentrations for individual plants were <5 mg/kg for ergovaline, <6 mg/kg for lolitrem B, and <48 mg/kg for peramine. Within each ecotype examined, significant variation (P < 0.05) in the mean concentrations of ergovaline, lolitrem B, and peramine was found between the populations of naturalised perennial ryegrass. Mean concentrations for some of the various naturalised populations were higher than that observed in some of the control cultivars. Low ergovaline and lolitrem B concentrations observed for individual genotypes indicate scope for selecting grass endophyte combinations characterised by optimum production of alkaloids.

scholarly journals Occurrence of Neotyphodium endophytes in perennial ryegreass (lolium perenne) and gescue (Festuca spp.), and characterisation of selected isolates with respect to toxin production, drought and insect resistance

2007 ◽  
Vol 13 ◽  
pp. 116-116
Author(s):  
Prathap Kumar Halady Shetty ◽  
Anne Mette Dahl Jensen ◽  
Niels Roulund ◽  
Birte Boelt
Keyword(s):  
Insect Resistance ◽  
Lolium Perenne ◽  
Toxin Production ◽  
Natural Grass ◽  
Neotyphodium Lolii

Neotyphodium endophytes infect the natural grass populations of Lolium perenne and Festuca sp. L. perenne samples were collected from 62 different locations in Denmark and were analysed for the presence of Neotyphodium lolii.

scholarly journals Determination of the toxic threshold of lolitrem B in cattle eating endophye-infected perennial ryegrass

2007 ◽  
Vol 13 ◽  
pp. 399-402
Author(s):  
L. Blythe ◽  
C. Estill ◽  
J. Males ◽  
A.M. Craig
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Clinical Signs ◽  
Positive Control ◽  
Control Group ◽  
Crossbred Cattle ◽  
Testing Laboratory ◽  
Neotyphodium Lolii ◽  
Lolitrem B

Perennial ryegrass (Lolium perenne) straw is used as a feed for livestock and horses. Some straw is infected with the endophyte, Neotyphodium lolii, which produces lolitrem tremorgens. Ingesting of the toxin produces clinical "ryegrass staggers." A 28 day feeding trail was conducted using 61 Black Angus, pure and crossbred cattle. The cattle were fed one of three levels of lolitrem B in chopped perennial ryegrass straw ranging from 0 ppb up to 3058 ppb. Four Japanese Wagyu crossbred cattle were fed chopped ryegrass straw containing 1400 ppb lolitrem B. The cattle were evaluated and scored twice a day for clinical signs of gait difficulties. Cattle consuming 1400 ppb lolitrem B did not show any overt clinical signs. After 14 days, 7 out of 15 cattle in the 1954 ppb lolitrem B group showed clinical signs of ataxia, stiffness, and tremors as seen in ryegrass staggers. All of the cattle in the positive control group of up to 3058 ppb lolitrem B with a 4 week mean of 2574 ppb developed clinical signs of staggers. None of the Wagyu cattle at 1400 ppb lolitrem B developed clinical signs. A dose response curve was developed based on the results of this study coupled with a prior study for use in the testing laboratory. Keywords: lolitrem B, perennial ryegrass, Lolium perenne, endophyte fungus, Neotyphodium lolii, cattle, threshold levels

Endophytic Neotyphodium lolii induced tolerance to Zn stress in Lolium perenne

2001 ◽  
Vol 113 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Fabien Monnet ◽  
Nathalie Vaillant ◽  
Adnane Hitmi ◽  
Alain Coudret ◽  
Huguette Sallanon
Keyword(s):  
Lolium Perenne ◽  
Neotyphodium Lolii ◽  
Induced Tolerance ◽  
Zn Stress

scholarly journals joint analyses of transcriptomic and metabolomic data to probe ryegrass-endophyte symbiosis

2007 ◽  
Vol 13 ◽  
pp. 195-198
Author(s):  
M. Cao ◽  
L. Johnson ◽  
R. Johnson ◽  
A. Koulman ◽  
G.A. Lane ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Molecular Mechanisms ◽  
Genetic Manipulation ◽  
Fungal Endophytes ◽  
Bioinformatics Analyses ◽  
Neotyphodium Lolii ◽  
Resistance To Insects ◽  
Metabolomic Data ◽  
Biochemical Mechanisms ◽  
Analyse Data

Fungal endophytes (Neotyphodium lolii) in perennial ryegrass (Lolium perenne) produce a range of bioactive alkaloids which are implicated in both toxicity to grazing animals and resistance to insects. The understanding of regulatory and biochemical mechanisms of the symbiosis will provide clues for the genetic manipulation of beneficial alkaloid production. This paper presents approaches to analyse data from high-throughput microarray experiments and targeted metabolomic analyses. Combined with bioinformatics analyses, potential genes were found associated with the accumulation of alkaloids and other metabolites. The advantages and limitations of our approach to address the molecular mechanisms of the symbiosis will be discussed. Keywords: Lolium perenne, Neotyphodium lolii, metabolomics, microarray

scholarly journals Survival of endophyte-infected ryegrass seed buried in soil

1999 ◽  
Vol 7 ◽  
pp. 151-156
Author(s):  
D.E. Hume ◽  
M.P. Rolston ◽  
D.B. Baird ◽  
W.J. Archie ◽  
M.R. Marsh
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seed Viability ◽  
Seed Storage ◽  
Fungal Endophyte ◽  
Grass Species ◽  
Soil Conditions ◽  
Neotyphodium Lolii ◽  
Viable Seeds ◽  
One Year

Emergence of volunteer perennial ryegrass (Lolium perenne L.) from seed buried in soil may contribute to the ingress of ryegrass in newly sown pastures. To investigate this, ryegrass seed infected with fungal endophyte (Neotyphodium lolii) was buried in nylon bags under pasture at two depths and at two sites (Palmerston North, Lincoln) in early/mid-autumn 1998. Seed bags were removed from the soil at intervals over the course of one year to determine seed viability and presence of endophyte in seedlings. Viability of seed declined rapidly to be 10% 3 months after burial. Further decline in viability was less, so that 12 months after burial 4% of seeds were still viable. Endophyte viability also declined, from 58% infection of seedlings at the time of burial to 21% at 12 months. This was at a slower rate than the decline in seed viability and from what might have been predicted from seed storage experiments. Viability of seed buried at 10 cm was greater than that buried at 3 cm (e.g., means, 10% and 1% after 6 months, respectively). This has implications for cultivation practices before pasture establishment. Seed buried at Lincoln maintained higher viability than seed buried at Palmerston North (e.g., means, 6% and 4% after 6 months, respectively), which was associated with drier soil conditions at Lincoln. Survival of buried seed may therefore be of greater importance in summer-dry east coast regions, compared with moist west coast environments or in wet years. The significance of buried ryegrass seed will depend on the numbers involved, but after 12 months there were still viable seeds left in the soil and some of these were infected with endophyte. This is important for pastures sown with ryegrass that is free of endophyte or infected with a selected endophyte, and for slower establishing grass species such as tall fescue. Keywords: endophyte, endophyte survival, Lolium perenne, Neotyphodium lolii, perennial ryegrass, seed burial, seed survival

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