Molecular Mechanisms of Interactions of Trichoderma with other Fungal Species

Trichoderma species are known globally mostly for the production of industrially useful enzymes as well as their biocontrol ability against plant pathogens. One of the major strategies of biological control is mycoparasitism against fungal pathogens of crop plants. However, till recently the mechanisms of mycoparasitism by biocontrol potential Trichoderma species at molecular level were not clearly understood. The biochemical signaling and the involvement of secondary metabolites that lead to mycoparasitic activities of Trichoderma, in particular, were not very clearly known earlier. Recent findings in this regard revealed that there are a number of signaling cascades activated during the process of mycoparasitism by Trichoderma species against phytopathogenic fungal pathogens. In addition Trichoderma also interacts with beneficial root inhabiting fungi like mycorrhizae. The interaction of Trichoderma species with mycorrhizal fungi is different as during interaction with mycorrhizal fungi different signaling cascades are activated that lead to a synergistic action. In the current review, we gathered updated evidences regarding the signaling cascades that are generated during interactions between Trichoderma species with fungal pathogens resulting mycoparasitism as well as interactions of Trichoderma species with mycorrhizal fungi resulting synergism at molecular level. We also highlighted the role of secondary metabolites that are reported to be associated in the signaling processes.