Artificial selection of suppressive or conducive rhizosphere microbiota circumvents the growth-defense trade-off due to a foliar pathogen

• Artificial selection shaped soil microbiota affecting foliar disease outcomes. • Suppressive soils reduced Pseudomonas syringae infection and disease severity. • Distinct bacterial communities emerged under suppressive and conducive selection. • Hormonal cross-talk (SA–JA) linked soil conditioning to plant immune responses. • Artificial selection modulated growth–defense trade-offs via rhizosphere microbiota. Plant-pathogen interactions are influenced by physiological responses and rhizospheric microorganisms, which can create disease-suppressive or disease-conducive soils affecting pathogen dynamics. This study used artificial selection to shape soil microbiota conditioned by Arabidopsis thaliana to either suppress or promote the foliar pathogen Pseudomonas syringae DC3000 ( Pst ). Over successive iterations, plants were inoculated with Pst , and soils were selected based on plant symptoms: enhanced resistance (suppressive), increased susceptibility (conducive), or no selection (control). A non-inoculated group (non-conditioned) was also included. Disease symptoms, Pst proliferation, and rhizosphere microbiota were monitored each iteration. Selection for suppressive soils reduced disease severity and Pst levels, while conducive soils showed the opposite. Each soil type was enriched in distinct bacterial communities. A growth-defense trade-off was evident in control soils but less so in selected soils. Gene expression analysis revealed that plant hormone homeostasis, especially salicylic acid (SA) and jasmonic acid (JA) played key roles with SA linked to local defense and JA to systemic responses. This work highlights artificial selection as a promising strategy to modulate soil microbiota, influencing plant-pathogen interactions and microbial dynamics.