Plants Assemble Species Specific Bacterial Communities from Common Core Taxa in Three Arcto-Alpine Climate Zones.
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, among which is the impact of climate zones on plant-associated microbiota. This is particularly true for wild plants in arcto-alpine biomes. Here, we hypothesized that the bacterial communities associated with pioneer plants in these regions have major roles in plant health support, and this is reflected in the formation of climate and host plant specific endophytic communities. We thus compared the bacteriomes associated with the native perennial plantsOxyria digynaandSaxifraga oppositifoliain three arcto-alpine regions (alpine, low Arctic and high Arctic) with those in the corresponding bulk soils. As expected, the bulk soil bacterial communities in the three regions were significantly different. The relative abundances ofProteobacteriadecreased progressively from the alpine to the high-arctic soils, whereas those ofActinobacteriaincreased. The candidate divisionAD3andAcidobacteriaabounded in the low Arctic soils. Furthermore, plant species and geographic region were the major determinants of the structures of the endophere communities. The plants in the alpine region had higher relative abundances ofProteobacteria, while plants from the low- and high-arctic regions were dominated byFirmicutes. A highly-conserved shared set of ubiquitous bacterial taxa (core bacteriome) was found to occur in the two plant species.Burkholderiales, ActinomycetalesandRhizobialeswere the main taxa in this core, and they were also the main contributors to the differences in the endosphere bacterial community structures across compartments as well as regions. We postulate that the composition of this core is driven by selection by the two plants.
Department of Microbial Ecology, University of GroningenGroningen, Netherlands; Department of Biological and Environmental Science, University of JyväskyläJyväskylä, Finland.
Manoj
M
Kumar
Health and Environment Department, AIT Austrian Institute of Technology Tulln, Austria.
Günter
G
Brader
Health and Environment Department, AIT Austrian Institute of Technology Tulln, Austria.
Angela
A
Sessitsch
Department of Biological and Environmental Science, University of Jyväskylä Jyväskylä, Finland.
Anita
A
Mäki
Department of Microbial Ecology, University of Groningen Groningen, Netherlands.
Jan D
JD
van Elsas
Department of Biological and Environmental Science, University of Jyväskylä Jyväskylä, Finland.
Riitta
R
Nissinen
Oxyria digyna; Saxifraga oppositifolia; arcto-alpine plant; biogeographical diversity; core bacteriome; endophytic bacteria