Root microbiome along an altitude gradient of the lithophytic Jankaea heldreichii, an endemo-relict species of Mount Olympus

We investigated the root microbiome of an endemo-relict plant species of Mount Olympus, Jankaea heldreichii, located at various altitudes (400m-1200m asl), through amplicon sequencing. Microbial communities (prokaryotes and fungi) revealed the significant impact of roots on tightly associated soils (P) that were less diverse and less altitude impacted compared with the loosely attached soils (S). The alpha-diversity of prokaryotes was highly affected by the root-soil environment (P vs S) whereas that of fungi was comparatively more sensitive to altitude. The P associated taxonomic groups, included well equipped taxa for tolerating various biotic and abiotic stresses (metal tolerance, microcystin degradation, psychrotolerance, chitin degradation), including drought, while the S associated taxa mainly included microorganisms with chemolithoautotrophic potential. The relative abundance of Nitrososphaeraceae decreased significantly at the lowest altitude location (P < 0.03) in S, could be an indicator of temperature and its effects for this key nitrogen cycling and greenhouse gas player. This is a first study on the root microbiome of J. heldreichii, a species dating back several million years ago, and paves the way for gaining deeper understanding of mountain microbiology, and the lessons to be taught about climate change and bioprospecting, straight from the steep inclines of Mount Olympus.