Abstract
Plant-pathogen interactions are shaped by multiple environmental factors, making it difficult to predict disease dynamics even in relatively simple agricultural monocultures. Here, we explored how variation in the initial soil microbiome predicts future disease outcomes at the level of individual plants. We found that the composition and functioning of the initial soil microbiome predetermined whether the plants survived or succumbed to disease. Surviving plant microbiomes were associated with specific rare taxa, highly pathogen-suppressing Pseudomonas and Bacillus bacteria, and high abundance of genes encoding antimicrobial compounds. Microbiome-mediated plant protection could subsequently be transferred to the next plant generation via soil transplantation. Together, our results suggest that small initial variation in soil microbiome composition and functioning can determine the outcomes of plant-pathogen interactions under natural field conditions.