ABSTRACT
The endohyphal bacteria (EHB) occur in living hyphae of phylogenetically diverse fungal endophytes isolated from various plant lineages and in multiple biogeographic provinces. EHB may be playing an important role in modulating the secondary metabolism of the fungus and loss of the endohyphal partner may result in attenuation of cultures for the production of key metabolites. This interaction represents the third component of plant–endophyte association, thus making it a tripartite association between the plant, fungus and bacteria. This tripartite relationship has a great impact on the host plant’s diversity, metabolism, and ecology. It is reported that the endohyphal bacteria play a complementary protective role for the host fungus and the host plant under various stress conditions. This remarkable symbiotic association has been poorly studied and the implications of the presence of endohyphal symbiotic partner on the metabolism of fungus and host plant are inadequately understood.
