Shift in the rhizosphere soil fungal community associated with root rot infection of Plukenetia volubilis Linneo caused by Fusarium and Rhizopus species

Abstract

BackgroundRoot rot disease caused by soilborne pathogens is a threat to agriculture, affecting plant survival and leading to yield losses. The soil in which plants grow is inhabited by bene cial microbiome playing essential roles in various aspects of host functionality and tness. However, this microbiome composition may change based on plant health status. MethodsIn the current study, we tested the pathogenicity of pathogenic fungi isolated from root rot infected P. volubilis plant tissues by inoculating them into healthy P. volubilis seedlings. Metagenomic sequencing was used to assess fungal community shifts in the rhizosphere of P. volubilis after root rot infection. ResultsFour Fusarium isolates and two Rhizopus isolates were found to be root rot causative agents in P. volubilis as they induced typical root rot symptoms in healthy seedlings. The metagenomic sequencing data showed that root rot infection altered the rhizosphere fungal community. In root rot infected soil, the richness and diversity indices increased or decreased depending on pathogens. The four most abundant phyla across all samples were Ascomycota, Glomeromycota, Basidiomycota, and Mortierellomycota. In infected soil, the relative abundance of each phylum increased or decreased depending on pathogen and functional taxonomic classi cation. ConclusionsBased on our results, we concluded that Fusarium spp. and Rhizopus spp. cause root rot infection of P. volubilis. In root rot infected P. volubilis, the response of the rhizosphere fungal community was pathogen dependent. These ndings may serve as a key point for a future study on biocontrol of root rot in P. volubilis.