ABSTRACT
To microbes, land plants present a complex, spatially and temporally diverse ecological habitat. Symbiotic associations between microorganisms and plants are ancient and fundamental, and many examples of complex and highly specific symbioses between plants and microbes have been described in detail. Endophytic microbes are an intriguing group of organisms associated with various tissues and organs of terrestrial and some aquatic plants, and are the subject of increasing interest to mycologists, ecologists, and plant pathologists. In general, "endophytic" infections are inconspicuous, the infected host tissues are at least transiently symptomless, and the microbial colonization can be demonstrated to be internal, either through histological means, by isolation from strongly surface disinfected tissue, or, most recently, through direct amplification of fungal nuclear DNA from colonized plant tissue. Infections of land plants by endophytes are ubiquitous, having been found throughout a broad range of host orders, families, and genera worldwide, and representing a diverse array of terrestrial and aquatic habitats.
