Succession of endophytic bacteria in the mountain sorrel (Oxyria digyna)
C. GIVEN (1), E. Häikiö (2), M. Kumar (1), R. Nissinen (1) (1) University of Jyväskylä, Finland; (2) University of Eastern Finland, Finland

Endophytic bacteria are known to associate with all plants, providing beneficial traits related to nutrient acquisition, stress tolerance and pathogen resistance. Little is known about the structure and function of endophytic bacterial communities in the arctic plants. We use Oxyria digyna as a model for arcto-alpine pioneer plant species. It is a perennial, non-mycorrhizal member of Polygonaceae, able to grow on mineral soils with very little nutrients. This study targets the acquisition and community structure of the endophytic bacteria in different tissues of O. digyna. In 2013, the micropropagated bait plants grown with minimal bacterial load were planted in the study site in Kilpisjärvi, Finland (69oN). Plants were harvested in August 2013 and in July, 2014, together with wild O. digyna growing adjacent to the plots. The total endophytic bacterial communities from leaves and roots were identified by 16s rRNA gene-targeted PCR with primers 1062F-1390R and next generation sequencing. The endophyte community structure was primarily determined by tissue type, as the leaf and root communities from all sample types grouped together. The bacterial species was significantly higher in the roots than in the leaves, and highest in the wild plants' roots. Succession towards wild type communities was detectable in the bait plants, with increase in the OTUs representing Acidobacteria, Actinobacteria, Firmicutes and Deltaproteobacteria. However, several genera abundant in the wild plants were not detected in the bait plants, indicating vertical transmission or acquisition in the early growth stages. Our data suggest that the majority, but not all endophytes can be acquired from the rhizosphere.

Abstract Number: C19-3, P4-121
Session Type: Concurrent