Grasses and endophytic fungi
Introduction
The relationship between certain grasses and endophytic (link) fungi is symbiotic(link). The most common benefit that the plant receives from the endophytic fungi is increased resistance to herbivores and other environmental stresses. (website). The endophytic fungi produce toxic alkaloids (link) that can deter herbivores or reduce the performance of the herbivore(article 2). The grass provides food and shelter for the fungi in return (fungus wiki 142). The discovery of this relationship occurred when cattle grazing on the infected grass developed delirium and “livestock staggering”(website).
Biological interaction
The relationship between endophytic fungi and grasses is systematically symbiotic. The defensive and most successful fungal endophytes produce no visble effects in plants. Even so, there are a variety of advantages the grass receives from the fungi. Enhanced insect and nematode resistance, fungal disease resistance, enhanced vegetative growth, and increased drought tolerance.
The endophytic fungi also receive benefits including greater access to nutrients, protection from desiccation, protection from surface feeding insects, and protection from parasitic fungi and competition among other microbes(book). Depending on both the fungal and grass species, the relationship can be very specific or have a wide range of possible host grass plants. Most symbiotic relationships are pleitropic (balanced) in the Epichloe and Neotyphodium genera. The other symbiotic relationships include nonpathogenic symbionts that transmit vertically by systematic infection of seed(asexual). This type of symbiosis is highly beneficial to the host. On the opposite end of the spectrum, there are antagonistic symbionts and transmit horizontally (contagious) and suppress host seed production(sexual).
Influence on other organisms: Negative: The fungi produce an alkaloid that is toxic to mammals. After consumption, the flow of blood is reduced to body extremities and the tail and hoof are prone to rot off. Reduce abundance of arbuscular mycorrhizal fungi.(article) Very vigorous plants, outcompete other plants.(article)
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Niche
Endophytic fungi are distributed in the intercellular portion of the host and restricted to above ground growth (book). This growth occurs in the floret, sheath, stem, and leaf tissues of the developing grass seedling and maturing plant (website). Endophytic fungi are considered an intercellular foliage symbiont and associations are established at the seedling stage and are long-lived.
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Microbial processes
What microbial processes are important for this microbial interaction? Does this microbial interaction have some ecosystem-level effects? Does this interaction affect the environment in any way? Describe critical microbial processes or activities that are important in this interaction, adding sections/subsections as needed. Look at other topics in MicrobeWiki. Are some of these processes already described? Create links where relevant.
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Key Microorganisms
What specific kinds of microbes are typically involved in this interaction? Or associated with important processes? Describe key groups (genera, species) of microbes that we find in this environment, and any special adaptations they may have evolved to survive in this environment. List examples of specific microbes that represent key groups or are associated with important processes found in this environment. Add sections/subsections as needed. Look at other microbe listings in MicrobeWiki. Are some of the groups of microbes from your environment already described? Create links to other MicrobeWiki pages where possible.
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Current Research
Enter summaries of recent research here--at least three required
References
Edited by <your name>, a student of Angela Kent at the University of Illinois at Urbana-Champaign.
