Identification and Characterization of Differentially Expressed Proteins from Trichoderma harzianum During Interaction with Colletotrichum falcatum Causing Red Rot in Sugarcane

In continuation of our earlier findings on suppression of C. falcatum by T. harzianum, the present study was attempted to characterize differentially expressed proteins from T. harzianum during its growth over C. falcatum metabolites. Proteomic analysis clearly indicated the degradation of C. falcatum proteins and expression of newer proteins by T. harzianum through SDS–PAGE. Two-Dimensional Electrophoresis (2-DE) of individual protein bands eluted from SDS–PAGE resulted in clear separation of 15 protein spots from 3 differentially expressed protein bands viz., DEPb1, DEPb2 and DEPb3. MALDI-TOF analysis of these proteins revealed that the identified 8 proteins were belonging to two functional categories viz., stress and defence (choline dehydrogenase, FKBP-type peptidyl-prolyl cis–trans isomerase, superoxide dismutase (Cu/Zn) and Hex1) and unknown function (Hypothetical proteins). The stress-related proteins were reported to be involved in biological suppression of various pathogens in other crops. In addition to this, 7 unknown function proteins expressed from T. harzianum during interaction with C. falcatum may play a major role in degradation of metabolites. Role of identified proteins was further confirmed during in-planta expression analysis by qRT-PCR, which showed the upregulation of selected proteins with distinct patterns at all the time interval during the tritrophic interaction of host, pathogen and antagonist and corresponding reduction in symptom production.