Different bacterial communities in ectomycorrhizae and surrounding soil. Bacterial communities in ectomycorrhizae

Unraveled by traditional and high throughput sequencing methods, several known eukaryotic symbioses have shown to host a rich diversity of prokaryotes that interact with their hosts. In this study, bacterial communities ectomycorrhizal root systems of 115 samples of Bistorta vivipara were compared to bacterial communities in 63 bulk soil samples from a 2m × 2m plot using pyrosequencing of 16S rDNA amplicons (V4 region). A high richness of Operational Taxonomic Units was found in plant ectomycorrhizae (3,571 OTUs) and surrounding soil (3,476 OTUs). Despite 2,628 OTUs were shared between ectomycorrhizae and the neighboring soil, bacterial community composition differed markedly between these two environments. A large proportion of the OTUs, especially those in plant roots, presented low similarity to Sanger 16S rRNA reference sequences, suggesting novel bacterial diversity in ectomycorrhizae. The analyzed ectomycorrhizae appear to present a distinct microbiome, which likely plays a role in the functioning of the plant-fungus symbiosis.