Abstract
The fruit surface is an infection court where foodborne pathogens compete with indigenous microbiota for microsites to invade
the fruits for nutrients acquisition. However, our current understanding of the structure and functions of fruit microbiome visa-vis postharvest pathogen infection is still nascent. Here, we sequenced the metagenomic DNA to understand the structural
and functional attributes of healthy and diseased kiwifruit microbiome. The healthy fruits exhibited higher microbial diversity
and distinct microbiome composition compared with diseased fruits. The microbiome of diseased fruit was dominated by
fungal pathogens Neofusicoccum parvum and Diplodiaseriata, while the microbiome of healthy fruits were enriched by
bacteria from Methylobacteriaceae, Sphingomonadaceae, Nocardioidaceae and fungi in Pleosporaceae. Importantly, the
healthy fruit microbiome had a higher relative abundance of genes related to ABC transporter, two-component system, bacterial
chemotaxis, bacterial secretion system, but had a lower relative abundance of genes associated with polycyclic aromatic
hydrocarbon degradation, amino sugar and nucleotide sugar metabolism, glycine, serine and threonine metabolism compared
with diseased fruits. Our results indicate that pathogen infection disrupts the fruit microbiome. The changes in microbiome
composition and functions could also increase the possibility of secondary pathogen infection as the reduced microbial
diversity may demonstrate less resistance to pathogens infection. Therefore, monitoring the microbiome dynamics and their
functions using metagenomic approaches could be useful to build a predictive understanding of accurate postharvest disease
diagnosis and management in the future.
