Endophytic interactions of Trichoderma harzianum in a tropical perennial rhizo-ecosystem

Abstract

This study demonstrates the endophytic interaction of the well-known growth promoting and biocontrol agent in black pepper. Trichoderma harzianum, coupled with its rhizosphere fungal flora was evidenced from metagenomics. We employed short-term and long-term strategies to study the interactions of T. harzianum in black pepper rhizosphere. In short-term strategy, T. harzianum was co-cultivated with axenic plantlets while pot culturing of plants in soil mixed with T. harzianum was performed in the long-term strategy. The colonization was investigated by light microscopy and scanning electron microscopy (SEM). The co-cultivation of T. harzianum with black pepper showed the intercellular colonization at 24 h and formation of intracellular hyphae with vesicles at 48 h of interaction. The long term strategy inferred that T. harzianum was able to colonize the black pepper roots along with the AMF inter- and intra-cellularly. The whole genome metagenomic sequencing brings out the population abundance of the entire rhizosphere fungal flora.