Showing papers on "Epichloë published in 1998"
TL;DR: How life history traits—such as fungal reproduction and pattern of infections and genotypic variation and ecological factors—in the ecology and evolution of endophytes and host plants is discussed are discussed.
Abstract: ▪ Abstract Endophytic fungi living asymptomatically within plant tissues have been found in virtually all plant species. Endophytes are considered plant mutualists: They receive nutrition and protection from the host plant while the host plant may benefit from enhanced competitive abilities and increased resistance to herbivores, pathogens, and various abiotic stresses. Limited evidence also indicates that endophytes may influence population dynamics, plant community diversity, and ecosystem function. However, most of the empirical evidence for this mutualism and its ecological consequences has been based on a few agronomic grass endophytes. More recent studies suggest that endophyte-host plant interactions are variable and range from antagonistic to mutualistic. A more comprehensive view of the ecology and evolution of endophytes and host plants is needed. This article discusses how life history traits—such as fungal reproduction and pattern of infections and genotypic variation and ecological factors—in...
1,022 citations
TL;DR: Epichloe species are endophytic symbionts of grasses which may differ in the relative importance of their sexual or asexual life cycles and are the only documented case of highly antagonistic strains interfertile with highly mutualistic strains.
96 citations
TL;DR: An endophytic fungus is observed in the intercellular spaces of the leaves and seeds of New Zealand and Australian specimens of Echinopogon ovatus, the first time that an endophyte-infected Neotyphodium species has been identified in grasses endemic to New Zealand or Australia.
Abstract: Grazing of Echinopogon spp. by livestock in Australia has caused symptoms similar to those of perennial ryegrass staggers. We observed an endophytic fungus in the intercellular spaces of the leaves and seeds of New Zealand and Australian specimens of Echinopogon ovatus. Culture of surface-sterilized seeds from New Zealand specimens yielded a slow-growing fungus. An examination in which immunoblotting and an enzyme-linked immunosorbent assay (ELISA) were used indicated that E. ovatus plants from Australia and New Zealand were infected with fungi serologically related to Neotyphodium lolii (the endophyte of perennial ryegrass) and other Epichloe and Neotyphodium spp. endophytic in pooid grasses. No lolitrems (the indole-diterpenoids implicated as the causative agents of perennial ryegrass staggers), peramine analogs, or ergot alkaloids were detected in the infected specimens by high-performance liquid chromatography or ELISA. However, in endophyte-infected E. ovatus plants from New Zealand, analogs of the indole-diterpenoid paxilline (thought to be a biosynthetic precursor of the lolitrems and related tremorgens) were detected by ELISA, and N-formylloline was detected by gas chromatography. Endophyte-free specimens of New Zealand E. ovatus did not contain detectable paxilline analogs or lolines and were more palatable than infected specimens to adults of the pasture pest Listronotus bonariensis (Argentine stem weevil). Hyphae similar to those of the E. ovatus endophyte were also found in herbarium specimens of Echinopogon nutans var. major, Echinopogon intermedius, Echinopogon caespitosus, and Echinopogon cheeli. This appears to be the first time that an endophytic Neotyphodium species has been identified in grasses endemic to New Zealand or Australia.
75 citations
01 Jan 1998
39 citations
TL;DR: Phylogenetic studies employing the ITS1 region of the rDNA suggest that Epichloe, as defined to include both endophytic and epibiotic species, is polyphyletic.
Abstract: Structural and rDNA studies were con- ducted on several Asian and African fungi with affin- ity to the genus Epichloe (Balansieae; Clavicipitaceae; Hypocreales). These species were found to be epi- biotic in habit, to produce brown to black ascomata, and to be symbionts of warm-season grasses. Epichloe spp. from Europe and North America are endophytic in habit, produce yellow to orange ascomata, and are symbionts of cool-season grasses. Phylogenetic studies employing the ITS1 region of the rDNA suggest that Epichloe, as defined to include both endophytic and epibiotic species, is polyphyletic. To improve the tax- onomy in this group of symbionts, a new genus Pa- repichloe is proposed to accommodate epibiotic spe- cies.
29 citations
TL;DR: Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize different sources of carbon and nitrogen and were characterized by limited growth whatever the substrate, the inhibition of their growth by high concentrations of glucose and fructose, and their inability to assimilate pentoses and nitrates.
Abstract: Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize different sources of carbon and nitrogen. These endophytes had been isolated from 12 different species of Poaceae and included Clavicipitaceae with or without a teleomorph (genera Epichloe and Neotyphodium, respectively) and species belonging to the genus Acremonium sensu stricto (Acremonium chilense-like). Pectin and cellulose as carbon sources and tryptophan and methionine as nitrogen sources appeared to support poorly the growth of most isolates. Hexoses, disaccharides, complex nitrogen sources, asparagine, and glutamine supported growth of all isolates. The isolates of genus Neotyphodium were characterized by limited growth whatever the substrate, the inhibition of their growth by high concentrations of glucose and fructose, and their inability to assimilate pentoses (xylose, arabinose) and nitrates. The isolates of genus Epichloe showed better growth than those of the previous group and their growth was not ...
9 citations