Biogeographical diversity and host plant specificity of bacterial endophyte communities in arcto-alpine plants
R. NISSINEN (1), M. Kumar (2), J. van Elsas (3), A. Sessitsch (4) (1) University of Jyväskylä, Finland; (2) University of Jyväskylä, Finland; (3) University of Groningen, Netherlands; (4) Austrian Institute of Technology, Austria

We are interested in the endophytic communities in the arcto-alpine plants. In this study we address the impact of climate zone, soil properties and plant species on the community composition of soil, rhizosphere and root endosphere bacteria of two arcto-alpine pioneer plant species, Oxyria digyna and Saxifraga oppositifolia. The soil and plant samples were collected from Finland (low Arctic, 69oN), Svalbard (high Arctic, 78oN) and Austria (alpine, 47oN). 16S rRNA gene targeted PCR and NG sequencing were used to characterize the bacterial communities. Community analysis revealed that soil bacterial communities were primarily shaped by climate and geographical location. The relative abundance of proteobacteria decreased and actinobacterial abundance increased from south to north in both endosphere and soil samples. Endophytic communities were clearly distinct from soil communities, and were also strongly shaped by plant species. These communities were formed from a core set of bacterial OTUs highly enriched in the endosphere in a plant species specific manner, despite the distance of over 3000 km and differences in climate and soil chemistry between the sampling sites. Many bacteria enriched in the endosphere of both of these pioneer plants belong to genera with plant beneficial properties, and isolates from O. digyna have been shown to e.g. solubilize phosphates at low temperatures. We suggest that cold climate plants harbor a conserved set of psychrotolerant endophytes.

Abstract Number: P4-111
Session Type: Poster