Elucidation of biocontrol mechanisms of Trichoderma harzianum against different plant fungal pathogens: Universal yet host specific response

In the present study, different transcripts of Trichoderma harzianum ThHP-3 were evaluated for their response against four fungal pathogens Fusarium oxysporum, Colletotrichum capsici, Colletotrichum truncatum and Gloesercospora sorghi using RT-qPCR. The time course study of T. harzianum transcripts related to signal transduction, lytic enzymes, secondary metabolites and various transporters revealed variation in expression against four fungal pathogens. In a broader term, the transcripts were upregulated at various time intervals but the optimum expression of cyp3, abc, nrp, tga1, pmk, ech42 and glh20 varied with respect to host fungi. Additionally, the expression of transcripts related to transporters/cytochromes was also observed against Fusarium oxysporum after 96 h whereas transcripts related to secondary metabolites and lytic enzymes showed significant difference in expression against Colletotrichum spp. from 72 to 96 h. This is first study on transcriptomic response of T. harzianum against pathogenic fungi which shows their host specific response.