Ultrastructure of Acremonium coenophialum, Acremonium lolii, and Epichloe typhina endophytes in host and nonhost Festuca and Lolium species of grasses

1987 ◽  
Vol 65 (11) ◽  
pp. 2357-2367 ◽  
Author(s):  
M. R. Siegel ◽  
U. Järlfors ◽  
G. C. M. Latch ◽  
M. C. Johnson
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Cell Walls ◽  
Fungal Endophytes ◽  
Potato Dextrose Agar ◽  
Natural Host ◽  
Acremonium Coenophialum ◽  
Ultrastructural Studies ◽  
Epichloë Typhina ◽  
Plant Grown

Ultrastructural studies were made of Acremonium fungal endophytes of tall fescue and perennial ryegrass and two isolates of Epichloe typhina. Hyphae of these fungi were observed in leaf sheaths of their natural host plant grown from infected seed and in artificially inoculated nonhost Festuca and Lolium species of grasses. Hyphae were also studied from fungal colonies grown on cellophane on potato dextrose agar. Crystalline inclusions were found in all endophyte–host combinations with the exceptions of E. typhina from perennial ryegrass in its own host and in a nonhost tall fescue, and Acremonium coenophialum in a nonhost perennial ryegrass. Tubular complexes were seen only in Acremonium lolii when growing in both host and in a non-host tall fescue. Three structures not seen before in endophytes (bundles of microtubules, 55 to 60 nm diameter "tubes," and bilayered cell walls) were found in E. typhina growing only in perennial ryegrass, its natural host. None of the distinguishing ultrastructural components described were found in hyphae grown in culture. Our observations suggest that endophytes express specific ultrastructural features only when they are grown in the grasses. However, it was not readily discernible what function the components serve and what role, if any, the natural versus the nonhost grass plays in the expression of endophyte ultrastructure.

scholarly journals Creation of stable associations between perennial ryegrass or tall fescue and fungal endophytes

Agronomie ◽  
1999 ◽  
Vol 19 (2) ◽  
pp. 133-144 ◽  
Author(s):  
Walid Naffaa ◽  
Claude Astier ◽  
Catherine Ravel ◽  
Jean-Jacques Guillaumin
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Fungal Endophytes

scholarly journals SEED TRANSMISSION OF PYRROLIZIDINE ALKALOID ACCUMULATION CAPACITY IN TALL FESCUE

1985 ◽  
Vol 65 (2) ◽  
pp. 317-321 ◽  
Author(s):  
T. A. JONES ◽  
R. C. BUCKNER ◽  
P. B. BURRUS II
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Pyrrolizidine Alkaloid ◽  
Critical Factor ◽  
Seed Transmission ◽  
Systemic Fungicide ◽  
Gas Liquid Chromatography ◽  
Acremonium Coenophialum ◽  
Epichloë Typhina ◽  
Loline Alkaloids

Pyrrolizidine alkaloids (N-formyl loline and N-acetyl loline) and the endophytic fungus tentatively identified as Sphacelia typhina (Pers.) Sacc. (= Acremonium coenophialum Morgan-Jones and W. Gams), the imperfect stage of Epichloe typhina (Fr.) Tul., have both been suspected as etiological agents of summer syndrome in tall fescue (Festuca arundinacea Schreb.). This syndrome is a toxicological disorder characterized by poor cattle growth with visible symptoms accentuated by high ambient temperatures. Alkaloid levels were measured with gas-liquid chromatography and presence or absence of the endophyte was determined by cytological observation. The endophyte was controlled by soil incorporation of the systemic fungicide benomyl. Variability was found among the 11 parental clones of the synthetic ’Kenhy’ for level of loline alkaloids. Loline alkaloids were present in seed of endophyte-infected panicles but absent in seed of endophyte-free panicles of the same clone. Progeny accumulated loline alkaloids only when their female parents were infected. These results suggest that the seed source is the critical factor for both the endophyte status of a plant and its capacity to accumulate loline alkaloids.Key words: Sphacelia typhina (Pers.) Sacc, Acremonium coenophialum Morgan-Jones and W. Gams, Epichloe typhina (Fr.) Tul., benomyl, ryegrass staggers

scholarly journals Establishing and maintaining a toxin-free pasture: a review

1999 ◽  
Vol 7 ◽  
pp. 123-132
Author(s):  
D.E. Hume
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Fungal Endophytes ◽  
Wild Type ◽  
Neotyphodium Lolii ◽  
Domestic Livestock ◽  
Buried Seed ◽  
On Farm ◽  
Sources Of Contamination

This paper reviews how new pastures may become contaminated with perennial ryegrass (Lolium perenne) infected with wild-type fungal endophytes (Neotyphodium lolii). These wild-type endophyte strains may be toxic to domestic livestock. Sources are from seed (natural reseeding, buried seed, sown seed, in dung, hay, carried on farm machinery) and survival of existing infected ryegrass plants. In particular, seed in soil and dung are reviewed. Contamination may occur both pre- and postestablishment. It is recommended that steps should be taken to minimise contamination from all sources when establishing new pastures. Although normal establishment practices for successful rapid establishment of weed-free pastures (e.g., cropping, fallow, herbicides) will minimise the risk of contamination, a number of cases highlight that extra time (e.g., 18-24 months planning rather 6- 12 months) and consideration of all sources of contamination is needed to minimise risk. Once established, further measures should be taken to prevent seed being transferred in dung or hay. This has implications when establishing pastures with endophyte-free ryegrasses, ryegrasses with selected non-toxic endophytes, a new ryegrass cultivar, or other grasses (e.g., tall fescue), whether for grazing by animals or for seed production. Keywords: endophyte, endophyte survival, faeces, Lolium perenne, natural reseeding, Neotyphodium lolii, pasture establishment, perennial ryegrass, seed burial, seed survival, tall fescue

scholarly journals Where do we go from here?

2007 ◽  
Vol 13 ◽  
pp. 515-518
Author(s):  
J.H. Bouton
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Multidisciplinary Approach ◽  
Fungal Endophytes ◽  
Leadership Roles ◽  
The Usa ◽  
Fungal Genomes ◽  
On Farm

The viability of this international symposium on grass/fungal endophytes is a direct measure of the nature and strength of the underlying science itself. The symposium's past was dominated by a multidiscipline approach and a geographic focus in New Zealand, USA, and Australia, due mainly to the economic impact of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.) when infected with Neotyphodium endophytes. There have been many research and technological findings reported during the past five symposia, with novel endophytes as an example of one having positive on-farm impact. In the future, it is anticipated that 1) the multidisciplinary approach will continue; 2) patenting issues will cause disruptions (hopefully small) in information sharing; 3) funding will drive the underlying science thereby continuing a concentration of work in New Zealand, Australia, and the USA, but opportunities will arise in these major countries for collaborative research with scientists in other geographies; 4) commercialisation and on-farm use of novel endophytes will expand; 5) sequencing and gene expression data will be available for the main fungal genomes, and microarray, genomics, and transciptome approaches will grow in importance; and 6) development of a "mind map" will help identify knowledge gaps for determining endophyte effects on animals. However, it was the inspiration, leadership, confidence, and even boldness of individual scientists in the field that pushed both this symposium and the science to the level it is today. Therefore, as the symposium moves forward, younger scientists need to assume leadership roles, and then be bold and confident in pushing forward; especially with continuing the symposium. Keywords: Neotyphodium, fungal endophytes, symposium, grasses, tall fescue, perennial ryegrass, biotechnologies

Epichloë-endophytes increase constitutive and herbivore-induced silicon defences in grasses but do not directly increase grass resistance to a chewing insect herbivore

2021 ◽  
Author(s):  
Ximena Cibils-Stewart ◽  
Wade J Mace ◽  
Alison J Popay ◽  
Susan E Hartley ◽  
Fernando A Lattanzi ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Fungal Endophytes ◽  
Maximum Effect ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Chemical Defences ◽  
Physical Defence ◽  
Si Supply

<p>Grasses accumulate large concentrations of silicon (Si) which alleviates a range of stresses including defence against herbivores. Likewise, grasses symbiotically associate with foliar <em>Epichloë-</em>fungal endophytes which provide herbivore defence, mainly via the production of alkaloids. Some <em>Epichloë</em>-endophytes increase foliar Si concentrations, particularly in tall fescue <em>(Festuca arundinacea</em>) but also in perennial ryegrass (<em>Lolium perenne</em>); it is unknown whether this impacts herbivores. Likewise, while Si is primarily a physical defence against herbivores, it can also affect defensive secondary metabolites; Si supply might therefore also affect alkaloids produced by <em>Epichloë</em>-endophytes, however, this remains untested. We grew tall fescue and perennial ryegrass in a factorial combination with or without Si supplementation, in the absence or presence of a chewing herbivore; <em>Helicoverpa armigera</em>. Grasses were associated with four different<em> Epichloë</em>-endophyte strains (tall fescue: AR584; perennial ryegrass: AR37, AR1, or wild type) or as <em>Epichloë</em>-free controls. Specifically, we assessed how Si supply and <em>Epichloë</em>-endophyte presence impacts plant growth and chemistry, and how their interaction with herbivory affects foliar Si concentrations and alkaloid production. Subsequently, their effects on <em>H. armigera</em> relative growth rates (RGR) were evaluated. In Fescue, the AR584-endophyte increased constitutive (herbivore-free) and induced (herbivore-inoculated) silicon concentrations when Si was supplied. In perennial ryegrass, AR37-endophyte increased constitutive and induced silicon concentration, meanwhile, AR1-endophyte increased constitutive levels only. Si supply and herbivory did not affect alkaloids produced by AR584- or AR1/Wt-endophyte in tall fescue and perennial ryegrass, respectively. However, Si suppressed herbivore-induced production of alkaloids in the AR37-endophyte perennial ryegrass association. Si was a more effective defence in tall fescue than perennial ryegrass, significantly reducing H. armigera RGR. Our results suggest that Si reduced herbivore performance to such an extent in tall fescue that it was operating at maximum effect and endophyte-mediated increases in Si concentration made no further difference. Si had a more modest impact on herbivores in perennial ryegrass, potentially linked to silicon decreasing herbivore feeding and thus, suppressing herbivore-induced alkaloids. We provide novel evidence that increased Si concentrations in some cases interact with endophyte-produced chemical defences, which could ultimately impact plant resistance to herbivores. <strong>  </strong></p>

Effects of endophyte consumption on food intake, growth, and reproduction in prairie voles

1998 ◽  
Vol 76 (5) ◽  
pp. 960-969 ◽  
Author(s):  
William F Durham ◽  
Michael G Tannenbaum
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Control Diet ◽  
Fungal Endophytes ◽  
Infected Plant ◽  
Plant Tissues ◽  
Acremonium Coenophialum ◽  
Prairie Voles ◽  
Two Generations ◽  
Domestic Livestock

Grasses infected with fungal endophytes are known to deter herbivores. Athough ingestion of infected plant tissues has detrimental effects on insects, birds, domestic livestock, and laboratory rodents, little is known about the consequences of endophyte consumption for wild rodent consumers. This multigenerational study investigated how consumption of tall fescue (Festuca arundinacea) seeds infected with the endophytic fungus Acremonium coenophialum affects prairie voles (Microtus ochrogaster). Breeding pairs were fed one of three base diets: laboratory rodent chow (C; control diet), 50% uninfected tall fescue seeds plus 50% chow (E-), or 50% endophyte-infected seeds plus 50% chow (E+). In the first generation, the E+ diet suppressed food and water intake, growth rates, and reproductive success, so no voles fed on the E+ diet could be followed in the second generation. In general, voles of the two generations performed similarly on the C and E- diets. Our findings show that prairie voles are sensitive to the presence of endophytes, or associated alkaloids, in their diets, and suggest that free-ranging voles avoid consuming endophyte-infected plant tissues if other foods are available.

scholarly journals Spontaneous in planta changes in fungal endophytes impact symbiosis

2007 ◽  
Vol 13 ◽  
pp. 191-193
Author(s):  
W.R. Simpson ◽  
M.J. Christensen ◽  
R.D. Johnson ◽  
J. Schmid
Keyword(s):  
Perennial Ryegrass ◽  
Cell Walls ◽  
Fungal Endophytes ◽  
Fungal Mycelium ◽  
Wild Type ◽  
In Planta ◽  
Neotyphodium Lolii ◽  
The Relationship ◽  
Host Tissues

The symbiosis between the asexual Ascomycetous fungi of the genus Neotyphodium and host grasses is considered to be symptomless. Symbioses involving Epichloë can show symptoms but this is restricted to the formation of stroma on floral structures. Fungal mycelium of both Epichloë and Neotyphodium endophytes occupy the intercellular space of plant tissues with no breach of host cell walls. Research involving these endophytes and their host grass symbioses relies on staining of host tissues and microscopic examination, immuno-detection or in-vitro isolation to determine infection status. This work reports on the observation of two independent instances of spontaneous change in the endophyte fungus that manifests as changes in the host grass vegetative morphology; one involving a genetically modified Epichloë festucae inoculated into a perennial ryegrass (Lolium perenne) population and the other a resident wild type Neotyphodium lolii. The relationship between wild type and variant fungus is confirmed as is the connection between variant fungus and host morphology. This work demonstrates that spontaneous in-planta changes in fungal endophytes occur and that these can impact on fungus/host grass symbioses. Keywords: Neotyphodium, Epichloë, symbiosis, endophyte, perennial ryegrass

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

2014 ◽  
Vol 65 (8) ◽  
pp. 747 ◽  
Author(s):  
D. E. Hume ◽  
J. C. Sewell
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Field Experiments ◽  
Insect Pests ◽  
Fungal Endophytes ◽  
High Stress ◽  
Agronomic Performance ◽  
Eastern Australia ◽  
Endophyte Infection

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 endophyte-free 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 × 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.

Detection of RFLPs in Perennial Ryegrass, Using Heterologous Probes from Tall Fescue

Crop Science ◽  
1992 ◽  
Vol 32 (6) ◽  
pp. 1366-1370 ◽  
Author(s):  
W. W. Xu ◽  
David A. Sleper ◽  
S. Chao
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue
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