Trichoderma: a beneficial antifungal agent and insights into its mechanism of biocontrol potential

Abstract Background Agriculture is an indispensable part of any country to feed the millions of people but it is under constant threat of pests. To protect the crops from this huge yield loss recently, chemical pesticides are used. Though chemical pesticides have shown effective results in killing the crop pests, it causes negative impact on the environment as well as humans. So to find an eco-friendly alternative, biological control methods are being used. Main body Biological control is a great renaissance of interest and research in microbiological balance to control soil-borne plant pathogens and leads to the development of a better farming system. In biological control, genus Trichoderma serves as one of the best bioagents, which is found to be effective against a wide range of soil and foliar pathogens. Genus Trichoderma is a soil inhabiting green filamentous fungus, which belongs to the division Ascomycota. The efficacy of Trichoderma depends on many abiotic parameters such as soil pH, water retention, temperature and presence of heavy metals. The biocontrol potential of Trichoderma spp. is due to their complex interaction with plant pathogens either by parasitizing them, secreting antibiotics or by competing for space and nutrients. During mycoparasitic interactions, production of hydrolytic enzymes such as glucanase, chitinase and protease and also signalling pathways are initiated by Trichoderma spp. and the important ones are Heterotrimeric G protein, MAP kinase and cAMP pathway. G protein and MAPK are mainly involved in secretion of antifungal metabolites and the formation of infection structures. cAMP pathway helps in the condition and coiling of Trichoderma mycelium on pathogenic fungi and inhibits their proliferation. Short conclusion Trichoderma being an efficient biocontrol agent, their characteristics and mechanisms should be well understood to apply them in field conditions to restrict the proliferation of phytopathogens.