Microbial Cargo: Do bacteria on symbiotic propagules reinforce the microbiome of lichens?

According to recent research, bacteria contribute as recurrent associates to the lichen symbiosis. Yet, the variation of the microbiomes within species and across geographically separated populations remained largely elusive. As a quite common dispersal mode, lichens evolved vertical transmission of both fungal and algal partners in specifically designed mitotic propagules. Bacteria, if co‐transmitted with these symbiotic propagules, could contribute to a geographical structure of lichen‐associated microbiomes.
The lung lichen was sampled from three localities in eastern Austria to analyse their associated bacterial communities by bar‐coded pyrosequencing, network analysis and fluorescence in situ hybridization. For the first time, bacteria were documented to colonize symbiotic propagules of lichens developed for short‐distance transmission of the symbionts. The propagules share the overall bacterial …