Trichoderma harzianum MTCC 5179 impacts the population and functional dynamics of microbial community in the rhizosphere of black pepper (Piper nigrum L.)

Abstract

Employing Illumine Hiseq whole genome metagenome sequencing approach, we studied the impact of Trichoderma harzianum on altering the microbial community and its functional dynamics in the rhizhosphere soil of black pepper (Piper nigrum L.). The metagenomic datasets from the rhizosphere with (treatment) and without (control) T. harzianum inoculation were annotated using dual approach, i.e., stand alone and MG-RAST. The pro-biotic application of T. harzianum in the rhizhosphere soil of black pepper impacted the population dynamics of rhizosphere bacteria, archae, eukaryote as reflected through the selective recruitment of bacteria [Acidobacteriaceae bacterium (p = 1.24e−12), Candidatus korib acter versatilis (p = 2.66e−10)] and fungi [(Fusarium oxysporum (p = 0.013), Talaromyces stipitatus(p = 0.219) and Pestalotiopsis fici (p = 0.443)] in terms of abundance in population and bacterial chemotaxis (p = 0.012), iron metabolism (p = 2.97e−5) with the reduction in abundance for pathogenicity islands (p = 7.30e−3), phages and prophages (p = 7.30e−3) with regard to func-tional abundance. Interestingly, it was found that the enriched functional metagenomicsignatures on phytoremediation such as benzoate transport and degradation (p = 2.34e−4),and degradation of heterocyclic aromatic compounds (p = 3.59e−13) in the treatment influenced the rhizosphere micro ecosystem favoring growth and health of pepper plant. Thepopulation dynamics and functional richness of rhizosphere ecosystem in black pepper influenced by the treatment with T. harzianum provides the ecological importance of T.harzianum in the cultivation of black pepper.