Home-field advantage affects the local adaptive interaction between Andropogon gerardii ecotypes and rhizobiome

Due to climate change, drought frequencies and severities are predicted to increase across the United States. Plant responses and adaptation to environmental stress depend on plant genetic and environmental factors. Understanding the effect of those factors on plant performance is required to predict the response of species to the environmental change. We used reciprocal gardens planted with dry, mesic and wet regional ecotypes of Andropogon gerardii to characterize the rhizosphere communities using 16S rRNA metabarcode sequencing. Even though the local microbial pool was the main driver of the rhizosphere microbial communities, the significant ecotypic effect highlighted the active plant recruitment driven by genetic variations. We also found that ecotypes do better in the recruitment of microbes when planted at homesite, supporting the “home field advantage” hypothesis. At homesites, ecotypes were more successful at recruiting rhizosphere community members unique to the locations -  microbial specialists that potentially linked the plant stress response functions. In addition, we found the support for ecotypic variations in recruitment of bacterial stains from the same genera, highlighting the effect of the plant on the rhizosphere microbiome recruitment. The results of this study should facilitate expanded studies on understanding the complexity of relationships between plant host interactions with local soil microbes and identification of functional potential of recruited microbes. Our study has the potential for further predicting ecosystem responses to climate change and the impact of management on restoration practices.