Fungal Endophytes: Defensive Characteristics and Implications for Agricultural Applications
Endophytes are the subject of intensive research, in part because of the potential they hold in agriculture as a source of bene cial effects to their host plants, such as increased vigor and tolerance to a range of abiotic and biotic stresses (Backman and Sikora, 2008; Kuldau and Bacon, 2008). They are de ned as organisms that asymptomatically infect the internal tissues of plants during at least part of their life cycle (see Petrini, 1991; Wilson, 1995; Saikkonen et al., 1998; Stone et al., 2000). In particular, fungal endophytes have been reported from all plant species surveyed, including representatives from all ecosystems. In addition, these fungi can be isolated from different plant organs and tissues, including roots, stems, branches, leaves, owers, and fruits (Saikkonen et al., 1998; Stone et al., 2000, 2004; Rodriguez et al., 2004; Arnold, 2007). Commonly found fungal endophytes (excluding mycorrhizal associations) belong to diverse classes of Ascomycota, mostly Dothidiomycetes, Leotiomycetes, and Sordariomycetes, although Basidiomycota endophytes have been observed to be common in some hosts (Stone et al., 2004; Crozier et al., 2006; Sieber, 2007; Thomas et al., 2008).