Proteomic analysis of the tripartite interaction between blackpepper,Trichoderma harzianumandPhytophthora capsiciprovides insights into induced systemic resistance mediatedbyTrichodermaspp.

Abstract

Trichoderma harzianum(MTCC5179) isthe biocontrol agent in the black pepper (Pipernigrum.L) production system against the destructive pathogen Phytophthora capsici which causes foot and root rot. We employed label-free quantitative proteomics to study the T. harzianum mediated induced systemic response in this system. We studied the defence response in leaves inT. harziznum primed plant roots which are also infected withP. capsici. The pattern of interactions was studiedas black pepper ×T.harzianum(two-way), blackpepper ×P. capsici(two-way) and black pepper ×T. harzianum×P. capsici(three-way). The proteinsinduced only in the three-way interaction were identified as Trichoderma induced resistance proteins.Eighteen reactive oxygen species-related proteinsand 22 defence-related proteins were identified as marker proteins. Apart from these groups, the ethylene synthesis, is of lavanoid pathway and lignin syn-thesis proteins were found to be enhanced. We re-port the early induced systemic resistance in leaves after Trichodermapriming at roots (72, and 96 h after interaction) against Phytophthora capsiciafter12 and 24 h of infection at roots. The peptides/proteins from this study will serve as important marker peptides/proteins for the induced systemic resistance in plants by Trichoderma.