Host-mediated rhizosphere microbiome transfer suppresses Fusarium oxysporum in banana

A plant's phenotype is determined by the traits of both the plant itself and its associated microbiome. However, we still have a poor understanding of the extent to which plant microbial recruitment contributes to disease resistance. We conducted a cross-inoculation experiment in which rhizosphere microbiomes from Fusarium wilt-resistant and susceptible banana varieties were collected and used to colonize the next planting cycle, and microbiome dynamics during recruitment and transfer were tracked. Culture-based approaches were used to construct synthetic microbial communities (SynComs) and test the effects of variety-specific metabolites on isolated strains. Transferring the rhizosphere microbiome from a highly resistant variety to a susceptible variety reduced Fusarium wilt pathogen abundance by 37.65% compared with transferring the susceptible plant's microbiome, while sterilized microbiomes had no detectable effect. Constructed SynComs recapitulated the suppressive effects of their source microbiomes, and metabolites derived from the highly resistant variety, characterized by enrichment of shikimic acid, stearic acid, and D-(-)-ribofuranose, promoted the growth of these beneficial microbes. Our results highlight that plant resistance levels are largely determined by the plant's ability to recruit a disease-suppressive microbiome, suggesting that enhancing microbial recruitment may represent an avenue to improve the disease resistance of susceptible varieties.