Endophytes are organisms often fungi andbacteria that live between living plant cells. Endophytic fungus is anendosymbiont that live within a plant for least part of his life withoutcausing apparent harm.
These are relatively unexplored producers of metabolitesuseful to pharmaceutical and agricultural industries (Petrini et al., 1992). Endophyticfungi are ubiquitos and have been found in all species of plant (Arnold et al.
,2000). Some strains of the same fungus isolated from different parts of thesame host differ in their ability to utilize different substances (Corell andPetrini, 1983). So, endophytes can be isolated from different plants belongs tothe different families and classes and grow under different ecological andgeographical conditions (Petrini et al., 1986). The type of interaction betweenan endophyte and plant is controlled by the genes of both organism andmodulated by environment (Moricca and Ragazzi, 2008).
Endophytic fungi is separated into fourclasses based on host range,type of tissue(s) colonize, colonization in planta,diversity in planta, transmission and fitness benefits (Rodriguez et al.,2009). Clavicipitaecous endophytesare class 1 endophytes which represents a small number of phylogeneticallyrelated Clavicipitaecous species.
They are fastidious in culture andlimited to some cool and warm season grasses (Stone et al., 2004; Bischoff et al.,2005). Class II endophytes comprise a diversityof species, all of which are members of the Dikarya(Ascomycota orBasidiomycota). They have ability to confer adaptation specific stresstolerance to hosts plants (Rodriguez et al., 2008). Class III endophytes are differentiatedon the basis of their occurrence and transmission. This includes vascular,nonvascular plants, woody and herbaceous angiosperm of Antarctic communities(Davis and Shaw, 2008; Higgins et al.
,2007). They are especially known for their diversity within individual hosttissues, plants and population.Class IV endophytes have darklymelanized septa and are restricted to plant roots. They are generally Ascomycetousfungi which are conidial or sterile and that form melanized structures likeinter and intracellular hyphae and also microsclerotia in the roots. This classof endophytes found in host plants like nonmycorrizal from Antarctic, alpine, subalpine temperate zones and tropical ecosystem (Jumpponen, 2001). Endophytic fungi have been considered aspossible useful sources of natural products and can protect plants from insectattack and diseases and are also able to produce substances of biotechnologicalimportance(Borges et al.
, 2007;Newman and Cragg, 2007; Strobel et al.,2004). Some species of endophytic fungi have been identified as sources ofanticancer, antidiabetic, insecticidal and immunosuppressive compounds(Strobeland Daisy, 2003). Some of them may produce secondary metabolites with potentialfor antimicrobial and anticancer property (Shu et al., 2005; Xu et al.,2008).
Fusarium oxysporum hasbeen isolated as endophytefrom medicinal plants with anticancer and antimicrobial activity (Xu et al., 2008).Other reports have alsoshowed that certain endophyic fungi produced more metabolites similar to thoseproduced by host plant with therapeutic function including alkaloids, steroids,terpenoids, flavinoids, quinines, peptides and phenolic acid (Shu et al., 2005; Strobel, 2003).