Adverse growth conditions reduce microbial diversity in the root and rhizosphere of S. viridis

Adverse growth conditions can inhibit plant growth, and multiple stress conditions have been shown to be alleviated by presence of specific microbes or microbial communities. The result of plant stress on microbial communities has shown that some taxa increase in stress response but overall effects on microbial diversity have not been characterized. In this work, we performed a systematic study using 4 adverse growth treatments across 2 soil conditions to determine effect of plant stress on microbiome diversity. Whether the initial diversity was high (wild soil) or low (autoclaved control), we observed a decrease in overall diversity in both root and rhizosphere compartments. This work suggests that the stress response of Setaria viridis results in lower ecosystem microbial diversity. Coupled with the ability of the microbiome to confer stress resistiance this suggests a negative feedback on ecosystem microbial diversity when plants are grown under increasingly adverse growth conditions, suggesting potential implications for plant and soil health in response to climate change.