PREDICTING, DETECTING AND CHARACTERIZING NUTRIENT EXCHANGES BETWEEN MAIZE AND SYNTHETIC BACTERIAL COMMUNITIES

Sustainable agricultural practices are necessary to mitigate climate change and produce more food, fiber, and renewable fuels. An untapped frontier in agriculture is to promote beneficial interactions with microbes as a sustainable mechanism of providing nutrients to crops. 'Microbial' products are already available to farmers; however, in practice, these products display highly variable results and current data suggest that this is tightly linked to the ability of the beneficial microbes to colonize and persist with their plant hosts. Plant root exudates are a major factor that determine the colonization and persistence phenotypes of exogenously supplied microbes; however, our knowledge of how plant exudates affect colonization and persistence is too limited to be translated into improved performance of microbial products. This proposal combines field level, computational observations with lab based, reductionist experiments. Together, these approaches will yield new synthetic communities of bacteria with plant growth promoting abilities and fundamental knowledge of how plant root exudates affect the colonization and persistence of the synthetic communities.In the proposed studies, multivariate datasets on root and shoot phenotypes from a field trial of 16 diverse maize lines will be leveraged with 323 candidate beneficial bacteria identified in the same study to computationally predict co-occurring or exclusionary (never co-occurring) microbial community members that lead to enhanced growth and plant productivity. Microbes within the communities will be isolated and characterized by genome sequencing and high throughput bioassays and nutrient exchange between plant roots and the microbial community will be quantified using isotopic labeling and metabolite profiling.The objectives of this proposal are as follows:1: Query existing field datasets to identify key components of robustly colonizing beneficial bacterial communities.2: Targeted culturing of root microbiome constituents and assembly of SynComs.3: In depth identification & metabolic characterization of the community players and interaction with maize over development.