A Sub-Antarctic Peat Moss Metagenome Indicates Microbiome Resilience to Stress and Biogeochemical Functions of Early Paleozoic Terrestrial Ecosystems

Premise of research. Abundant peat mosses and epibiotic microbiota, common in widespread modern peatlands, constitute complex biotic systems recognized to provide globally significant ecosystem services: organic carbon sequestration, methane oxidation, and nitrogen fixation. Because recent fossil and molecular diversification evidence indicates that peat mosses are >450 Myr old, they may be among Earth’s earliest land plants. The biogeochemical effects of early vegetation, which may have occupied remote islands and experienced nutritional stress and episodes of high UV radiation, are poorly understood. To gain insight into taxonomic composition, biogeochemical function, and resilience of archaic peat moss microbiomes, we performed shotgun metagenomic sequencing of a similarly stressed modern peat moss.Methodology. Sphagnum fimbriatum was sampled from Chilean sub-Antarctic Navarino Island, which is remote from nutrient pollution and subject to high UV beneath the southern ozone hole. 16S, 18S, 23S, and 28S...