Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia
Gopala Krishnan, M. K., van Elsas, J. D., & Nissinen, R. (2017). Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia. Frontiers in Microbiology, 8, Article 1972. https://doi.org/10.3389/fmicb.2017.01972
Published inFrontiers in Microbiology
© 2017 the Authors. This is an open access article distributed under the terms of the Creative Commons Attribution License.
Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB) communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel) and Saxifraga oppositifolia (blue saxifrage), in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region) and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH-targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ-Proteobacteria) were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and rhizosphere soil as well as the endosphere communities in the Mayrhofen region were all characterized by high relative abundances of nifH sequences related to Geobacter. In contrast, the endosphere and soil (bulk or rhizosphere soil) communities in the High Arctic were highly divergent: endosphere communities in the arctic regions were shaped by Clostridium spp., while nifH sequences representing δ-Proteobacteria, β-Proteobacteria, Cyanobacteria (in Ny-Ålesund), and Verrucomicrobia (in Kilpisjärvi) dominated the soil communities. Interestingly, the major PNFB genera identified in this study have been previously identified as members of conserved core microbiomes in the endospheres and seeds of these plants by 16S rRNA gene based analyses combined with bacterial isolation, suggesting a very tight interaction between diazotrophic bacteria and these arctic pioneer plants. Overall, anaerobic bacterial taxa dominated the PNFB communities of the endospheres and rhizospheres of the two plant species in all study sites. This could indicate anoxic conditions in and around plant roots at the time of sampling (early growth season), created by melting snow and underlying permafrost. ...
PublisherFrontiers Research Foundation
Publication in research information system
MetadataShow full item record
Except where otherwise noted, this item's license is described as © 2017 the Authors. This is an open access article distributed under the terms of the Creative Commons Attribution License.
Showing items with similar title or keywords.
Tissue-Specific Dynamics in the Endophytic Bacterial Communities in Arctic Pioneer Plant Oxyria digyna Given, Cindy; Häikiö, Elina; Kumar, Manoj; Nissinen, Riitta (Frontiers Media, 2020)The rapid developments in the next-generation sequencing methods in the recent years have provided a wealth of information on the community structures and functions of endophytic bacteria. However, the assembly processes ...
Assembly and functioning of endophytic bacterial communities in arcto-alpine pioneer plant Oxyria digyna Given, Cindy Jittrapan (2019)Plant microbiomes consist of diverse communities of microorganisms, among which bacteria are highly abundant. The microbiomes are crucial for plants as they rely on their microbial associates for many essential functions. ...
Plants Assemble Species Specific Bacterial Communities From Common Core Taxa in Three Arcto-Alpine Climate Zones Gopala Krishnan, Manoj Kumar; Brader, Günter; Sessitsch, Angela; Mäki, Anita; Elsas, Jan Dirk Van; Nissinen, Riitta (Frontiers Research Foundation, 2017)Evidence for the pivotal role of plant-associated bacteria to plant health and productivity has accumulated rapidly in the last years. However, key questions related to what drives plant bacteriomes remain unanswered, ...
Nissinen, Riitta; Helander, Marjo; Gopala Krishnan, Manoj Kumar; Saikkonen, Kari (Nature Publishing Group, 2019)Keystone microbial species have driven eco-evolutionary processes since the origin of life. However, due to our inability to detect the majority of microbiota, members of diverse microbial communities of fungi, bacteria ...
Poosakkannu, Anbu (University of Jyväskylä, 2016)Plant-associated microbes could play a role in plant colonization of sand dune ecosystems, but microbes associated with plants colonizing those ecosystems in the arctic are poorly known. I characterized Deschampsia ...