Whole-genome duplication and host genotype affect rhizosphere microbial communities

The composition of microbial communities found in association with plants is influenced by host phenotype and genotype. Yet, the ways in which specific genetic architectures of host plants shape microbiomes is unknown. Genome duplication events are common in the evolutionary history of plants, influence many important plant traits, and, thus, they may affect associated microbial communities. Using experimentally induced whole genome duplication (WGD), we tested the effect of WGD on rhizosphere bacterial communities in Arabidopsis thaliana. We performed 16S rRNA amplicon sequencing to characterize differences between microbiomes associated with specific host genetic backgrounds (Columbia vs. Landsberg) and ploidy levels (diploid vs. tetraploid). We modeled relative abundances of bacterial taxa using the Dirichlet and multinomial distributions via a hierarchical Bayesian approach. We found that host genetic background and ploidy level affected rhizosphere community composition. We then te...