P-298 - A dual approach to investigating the role of arbuscular mycorrhizal fungi in rhizosphere bacterial community assembly

The overuse of synthetic nitrogen fertilizers in agriculture continues to have detrimental environmental impacts, driving the need for sustainable alternatives. Nitrogen-fixing microbial inoculants are a promising solution; however, commercial inoculants are often limited in their efficacy due to failed establishment. The development of robust microbial consortia remains challenging, partly due to an underdeveloped understanding of key microbial interactions. The role of arbuscular mycorrhizal fungi (AMF) in shaping and stabilizing rhizosphere microbial communities is often overlooked. Here we employ a multifaceted approach to investigate how AMF influences microbial community assembly under nitrogen-limited conditions. First, we analyze 16S and AMF SSU amplicon sequencing results from a nitrogen-limited field, using network analysis and plant phenotypic data to identify key microbial associations. Second, we propose successive pot experiments in which microbial communities from Missouri native prairies are repeatedly passed through nitrogen-limited Brachypodium distachyon inoculated with Rhizophagus irregularis. The output from each succession will be sequenced to track community assembly and relative abundance. The combined field and pot experiment datasets will be used to understand the extent that AMF influences root microbiome assembly and stability, providing insight into the design of stable and effective synthetic microbial communities for agricultural deployment.