Off‐target metagenomics: Leveraging whole genome sequencing to study the bacteriome of the liverwort Calasterella californica

Premise: The recovery of non-target organism reads, especially when whole organisms are sampled, constitutes a great opportunity for studying microbial communities. The increase in whole genome sequencing feasibility and the development of new marker-based pipelines enable the use of short reads to study bacterial communities associated with organisms. Methods: obtained through the California Conservation Genomics Project to characterize the composition of its associated bacterial communities and explore its variation across the geographic space. Results: and other Hyphomicrobiales, a group that includes well-known plant symbionts. While diversity metrics of bacteria composition were similar across localities, we found significant differences in the relative abundance of a few taxa across California regions, likely driven by differences in precipitation and temperature seasonality. Discussion: Our results support previous observations that liverwort bacterial communities are not randomly assembled, suggesting a potential role of the plant in determining community composition, an emerging pattern that deserves more attention. The novel off-target metagenomics approach can be applied to any population-level resequencing where whole organisms are sequenced, opening the door to exciting avenues of microbiome research using repurposed data from landscape genomics.