P-326 - Enrichment activities: untangling plant salicylic acid selection mechanisms to generate beneficial microbiomes

Plants are colonized by unique microbiomes that confer benefits including nutrient acquisition, development, stress tolerance, and pathogen protection. While harnessing beneficial microbiome members has great potential, their efficacy in complex natural systems during microbiome assembly remains unclear. This study capitalizes on previous experiments that passaged microbial communities through salicylic acid (SA) mutant Arabidopsis thaliana (Arabidopsis) plants, resulting in unique enrichment communities (EnComs). Here, we investigate how these EnComs, as well as isolated strains from them, interact with wildtype Arabidopsis. Inoculation with single isolated strains on wildtype plants has demonstrated a spectrum of symbiosis from plant growth promotion to opportunistic pathogens, which did not reveal themselves in the full EnComs on their host genotype of origin. This suggests an essential role of both immune status and microbial interactions in plant microbiome assembly. To untangle this intersection, we will use our EnComs to inform bacterial synthetic communities (SynComs) for future experiments. Furthermore, investigating the effect of EnComs on wildtype plants will further elucidate a broader microbiome impact on plant health outcomes. These findings offer insights into the role the plant plays in establishing a relationship with members of the community for a specific outcome and how this can inform the future usage of biocontrol or growth promoting agents.