PT  - JOURNAL ARTICLE
AU  - Marta Alonso-García
AU  - Juan Carlos Villarreal A.
TI  - Geography, not host identity, shapes bacterial community in reindeer lichens
AID  - 10.1101/2021.01.30.428927
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.01.30.428927
4099  - http://biorxiv.org/content/early/2021/01/31/2021.01.30.428927.short
4100  - http://biorxiv.org/content/early/2021/01/31/2021.01.30.428927.full
AB  - Background and Aims Tremendous progress have been recently achieved in host-microbe research, however, there is still a surprising lack of knowledge in many taxa. Despite its dominance and crucial role in boreal forest, reindeer lichens have until now received little attention. We characterize, for the first time, the bacterial community of four species of reindeer lichens from Eastern North America’s boreal forests. We analysed the effect of two factors (host-identity and geography) in the bacterial community composition, we verified the presence of a common core bacteriota and identified the most abundant core taxa.Methods Morphological and molecular lichen species delimitation was performed based on the ITS region. The bacterial community of around 200 lichen samples was characterised using the 16S rRNA gene.Key Results Our results showed that host-lichen identity does not determine bacterial community composition in reindeer lichens, but we confirmed the influence of geography in shaping the diversity and abundance of bacteria associated to the species Cladonia stellaris from lichen woodlands. We also revealed that reindeer lichens share a reduced common core bacteriota composed exclusively by Proteobacteria.Conclusions The bacterial community in reindeer lichens is not host-selective. Northern lichen woodlands exhibit a significant higher diversity and abundance of bacteria associated to Cladonia stellaris. Nevertheless, the specific role of those bacteria as well as the process of host colonization remains to be determined. Elucidating these two aspects would be key to have a better understanding of the whole boreal ecosystems. The reduced and not diverse core bacteriota of reindeer lichens might be due to the larger size of our study area. The presence of the species Methylorosula polaris in the core bacteriota is evident and might have a particular importance for reindeer lichens.Competing Interest StatementThe authors have declared no competing interest.