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Achnatherum inebrians, colloquially known as drunken horse grass, is associated with livestock toxicity in northern China. Epichloë gansuensis (Eg) was described from endophyte isolates from A. inebrians in Sunan County, Gansu Province, whereas a morphologically distinct variety, E. gansuensis var. inebrians (Ei), was described based on two isolates from A. inebrians seeds collected in Urumqi County, Xinjiang Province. Genome sequencing and alkaloid analyses also distinguish these taxa; the Ei isolates produce neurotropic lysergic acid amides (ergot alkaloids), and an Eg isolate produces paxilline (an indole-diterpene alkaloid). To better elucidate the taxonomic diversity of Epichloë spp. symbiotic with A. inebrians, we surveyed eight populations in Xinjiang, Gansu and Inner Mongolia provinces of China and analyzed their genotypes by multiplex PCR for alkaloid biosynthesis genes and mating-type genes. Genotypes consistent with Ei were present in all eight populations, of which they dominated seven. The Ei isolates were all mating type A and tested positive for the ergot alkaloid gene, dmaW. In contrast Eg isolates were all mating type B and had the indole-diterpene gene, idtG. The genome was sequenced from an Ei isolate from seeds collected in Xiahe County, Gansu, and compared to that of the varietal ex type isolate from Urumqi. Alkaloid genes and four different housekeeping genes were nearly identical between the two sequenced Ei isolates and were distinct from a sequenced Eg isolate. Phylogenetic analysis placed Ei, Eg and Epichloë sibirica into respective subclades of a clade that emanated from the base of the Epichloë phylogeny. Given its chemotypic, genotypic, morphological and phylogenetic distinctiveness, its widespread occurrence in rangelands of northern China, and its importance in livestock toxicity, we propose raising Ei to species rank as Epichloë inebrians., (© 2015 by The Mycological Society of America.) more...

Plant symbiotic fungi (endophytes) of the genus Neotyphodium [anamorphs, asexual derivatives of Epichloë (Ascomycota: Clavicipitaceae)] often associate with grass species of the subfamily Pooideae, which includes important forage and turf species. These endophytes are known to produce a range of alkaloids that enhance their host's resistance to insects or are toxic to grazing animals. Among the alkaloids, loline alkaloids (saturated 1-aminopyrrolizidines) are generally observed in the highest concentrations in many Neotyphodium–grass symbiotic associations, and are known to be toxic to insects but not to mammals. Some Neotyphodium-infected grasses have enhanced resistance to rice leaf bug, Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae), one of the major pests for rice production in Japan. Our laboratory experiments quantified the effects of purified loline ( N-formylloline) and in planta synthesis of loline alkaloids by meadow fescue [ Lolium pratense (Huds.) S.J. Darbyshire (syn. Festuca pratensis Huds.)]– Neotyphodium uncinatum (Gams, Petrini & Schmidt) Glenn, Bacon & Hanlin and Italian ryegrass ( Lolium multiflorum Lam.)– Neotyphodium occultans Moon, Scott & Christensen associations on the development and survival of T. caelestialium. No-choice feeding assays with laboratory populations of the insect revealed that their growth was significantly decreased by the infected grasses, and the effect was greater for N. uncinatum than for N. occultans, in keeping with differences in N-formylloline concentrations in the plants. Artificial feeding of N-formylloline through feeding sachets indicated that the chemical has an adverse effect on survival of larvae, even at the lowest concentration tested (50 µg/g), which was considerably lower than the typical concentrations in many Neotyphodium–grass association s. The results confirmed the ability of Neotyphodium-infected forage grasses to control T. caelestialium propagation in meadows, which may cause damages to nearby rice paddies. [ABSTRACT FROM AUTHOR] more...

Neotyphodiumfungal endophytes form mutualistic symbiotic associations with many grasses of the subfamily Pooideae, including important forage and turfgrass species. This relationship provides a competitive advantage to the host plant by increasing abiotic/biotic stress tolerance, such as its resistance to drought, diseases, and insect pests. The insect deterrent effects of endophytes are now receiving attention in Japan, as insect pests growing in meadows are causing problems in adjacent rice paddies. One of the most serious problems is the kernel spotting of rice grains caused by the rice leaf bug,Trigonotylus caelestialiumKirkaldy (Heteroptera: Miridae), which reproduces onLoliumspecies grown as forage. To determine the potential ofNeotyphodiumendophytes to reduce the invasion of rice crops byT. caelestialiumfrom adjacentLoliumcrops, we carried out choice and no-choice feeding tests using endophyte-infected and endophyte-free clonal perennial ryegrass (Lolium perenneL.) (Poaceae). Our experiments revealed that the presence of theNeotyphodiumendophyte strongly deterred the feeding of both first-instar larvae and adults ofT. caelestialium. These results show the potential ofNeotyphodiumendophytes to reduce the number ofT. caelestialiumin forage fields and grasslands, and thus to reduce the damage to rice grains caused by this insect pest. [ABSTRACT FROM AUTHOR] more...

Neotyphodium endophytes are vertically transmitted fungal symbionts of grasses. Being pest-repelling and growth-promoting agents for their hosts, and also potential mycotoxin producers, their detection in plants is important. Observation of chemically cleared flowers of infected grasses (Festuca arundinacea, F. pratensis, Lolium perenne, and L. multiflorum) using differential interference contrast microscopy revealed the existence of endophytes within immature ovaries of host plants. This observation method provides an accurate and easy way to detect and distinguish Neotyphodium endophytes in flowering host grasses and to investigate the seed transmission process, which is critical to their life cycle, and the practical use of infected plants. [ABSTRACT FROM AUTHOR] more...