Figure 1: Genetic variation within A. thaliana shapes the composition of the best-sequenced members of the microbial community.

(a) Using eigenvector techniques, inbred replicates of A. thaliana cluster together only when analysing the most heavily sequenced bacteria. Nevertheless, the vast majority of the sequencing effort characterizes a small number (and %) of taxa in each community. (b) Taken together, this implies that vagrant species and other poorly characterized/sequenced taxa (and occasionally, sequencing artefacts) obscure evidence that hosts shape their microbial communities. (c) Host-genetic variation within A. thaliana also affects the ability of fungi to colonize and proliferate on its leaves. All P values take into account technical confounders.