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Neotyphodium

About: Neotyphodium is a research topic. Over the lifetime, 591 publications have been published within this topic receiving 25206 citations.


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Journal ArticleDOI
TL;DR: Longitudinal studies suggest that the prevalence of seed‐transmitted endophytes can increase rapidly over time, and estimates of infection frequency have revealed variable levels of infection with especially high prevalence in the subfamily Pooideae.
Abstract: Over the past 20 yr much has been learned about a unique symbiotic interaction between fungal endophytes and grasses. The fungi (Clavicipitaceae, Ascomycota) grow intercellularly and systemically in aboveground plant parts. Vertically transmitted asexual endophytes forming asymptomatic infections of cool‐season grasses have been repeatedly derived from sexual species that abort host inflorescences. The phylogenetic distribution of seed‐transmitted endophytes is strongly suggestive of cocladogenesis with their hosts. Molecular evidence indicates that many seed‐transmitted endophytes are interspecific hybrids. Superinfection may result in hyphal fusion and parasexual recombination. Most endophytes produce one or more alkaloid classes that likely play some role in defending the host plant against pests. Hybridization may have led to the proliferation of alkaloid‐production genes among asexual endophytes, favoring hybrids. The ergot alkaloid ergovaline, lolitrems, and lolines are produced by only a ...

981 citations

Journal ArticleDOI
TL;DR: The endophytes gain shelter, nutrition, and dissemination via host propagules, and can contribute an array of host fitness enhancements including protection against insect and vertebrate herbivores and root nematodes, enhancements of drought tolerance and nutrient status, and improved growth particularly of the root.
Abstract: Grasses (family Poaceae) and fungi of the family Clavicipitaceae have a long history of symbiosis ranging in a continuum from mutualisms to antagonisms. This continuum is particularly evident among symbioses involving the fungal genus Epichloe (asexual forms = Neotyphodium spp.). In the more mutualistic symbiota, the epichloe endophytes are vertically transmitted via host seeds, and in the more antagonistic symbiota they spread contagiously and suppress host seed set. The endophytes gain shelter, nutrition, and dissemination via host propagules, and can contribute an array of host fitness enhancements including protection against insect and vertebrate herbivores and root nematodes, enhancements of drought tolerance and nutrient status, and improved growth particularly of the root. In some systems, such as the tall fescue N. coenophialum symbioses, the plant may depend on the endophyte under many natural conditions. Recent advances in endophyte molecular biology promise to shed light on the mechanisms of the symbioses and host benefits.

800 citations

Journal ArticleDOI
01 Feb 1988-Ecology
TL;DR: Experiments demonstrate that plant growth and seed production can be increased by infection of systemic fungal endophytes in grasses, suggesting a defensive mutualism in which the fungi defend their hosts against herbivory, thereby defending their own resources.
Abstract: Many grasses are infected by systemic fungal endophytes (family Clavicipitaceae, Ascomycetes) that produce pysiologically active alkaloids in the tissues of their hosts. Infection makes grasses toxic to domestic mammals and increases resistance to insect herbivores. Some grasses are sterilized by endophyte infection while remaining vegetatively vigorous; other infected grasses remain completely fertile. Experiments demonstrate that plant growth and seed production can be increased by infection. This symbiotic association may be a defensive mutualism in which the fungi defend their hosts against herbivory, thereby defending their own resources. Recent studies suggest that defensive mutualism of endophytes with grasses may be widespread.

800 citations

Journal ArticleDOI
TL;DR: Understanding mechanisms of abiotic stress tolerance in endophyte-infected grasses is essential for continued improvement and persistence of grasses for a range of applications, e.g., forage for semi-arid areas or cover plants for soil renovation.
Abstract: Cool-season grasses infected with Neotyphodium spp. endophytes have an extraordinary impact on the ecology and economy of pasture and turf. A range of adaptations of endophyte-infected grasses to biotic and abiotic stresses has been identified but mechanisms of these adaptations are not clearly understood. In this review, we present recent research progress on endophyte-related mechanisms affecting abiotic (drought, mineral) and selected aspects of biotic stress tolerance in cool-season grasses. Endophytes induce mechanisms of drought avoidance (morphological adaptations), drought tolerance (physiological and biochemical adaptations), and drought recovery in infected grasses. Mineral nutrition (nitrogen, phosphorus, calcium) affects production of ergot alkaloids, thus understanding mechanisms involved in mineral economy of endophyte-infected grasses will help in developing management practices to reduce forage toxicity to livestock. Previous research resolved the role of endophyte in nitrogen (N) economy of tall fescue. We identified two endophyte-related mechanisms in tall fescue operating in response to phosphorus (P) deficiency. The mechanisms are altered root morphology (reduced root diameters and longer root hairs) and chemical modification of the rhizosphere resulting from exudation of phenolic-like compounds. These mechanisms were shown to benefit endophyte-infected plants grown under P deficiency. We also report a mechanism of aluminum (Al) sequestration on root surfaces in endophyte-infected tall fescue, which appears to be related to exudation of phenolic-like compounds with Al-chelating activity. Understanding mechanisms of abiotic stress tolerance in endophyte-infected grasses is essential for continued improvement and persistence of grasses for a range of applications, e.g., forage for semi-arid areas or cover plants for soil renovation.

741 citations

Journal ArticleDOI
TL;DR: This research has shown clearly that plants benefit from a widespread mutualistic association between grasses, the authors' most familiar and important plant family, and endophytic fungi.
Abstract: Mutualistic interactions between species are receiving increased attention from ecologists, although research lags far behind analogous work on competition or predator-prey interactions. Most research has focused on rather showy mutualisms such as pollination or fruit dispersal and has suggested that mutualisms are more important in tropical communities than in temperate communities (67). Plant-microbial mutualisms, in contrast, have prompted little ecological research. Plant-microbial associations are more difficult to observe and manipulate than plant-animal associations. Many plants are always infected (e.g. legumes by rhizobia, forest trees by mycorrhizal fungi), so it is easy to consider the microorganisms merely as a special type of plant organ. Further, plant-microbial mutualisms historically have been outside the realm of ecology, in other areas of biology like microbiology and mycology. Recent research has revealed a widespread mutualistic association between grasses, our most familiar and important plant family, and endophytic fungi. Asymptomatic, systemic fungi that occur intercellularly within the leaves, stems, and reproductive organs of grasses have dramatic effects on the physiology, ecology, and reproductive biology of host plants. Through the production of toxic alkaloids, endophytic fungi defend their host plants against a wide range of insect and mammalian herbivores. Poisoning of domestic livestock has spurred a great deal of research on endophytic fungi in pasture grasses. This research has shown clearly that plants benefit from

598 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20238
202215
20211
20201
20192
20181