Data di Pubblicazione:
2012
Citazione:
Succession of a bacterial rhizospheric community along a chronosequence of a cold desert / F. Mapelli, G. Tsiamis, B. Scaglia, R. Marasco, A. Balloi, E. Rolli, F. Tambone, S. Vasileiadis, F. Adani, K. Bourtzis, S. Borin, D. Daffonchio. ((Intervento presentato al 3. convegno BIODESERT International Workshop - Microbial diversity in desert extreme environment “Microarrays from theory to application” tenutosi a Tunisi nel 2012.
Abstract:
Global warming and ongoing climate changes result in glacier retreat at different latitude and
altitude on Earth. Ice melting determines the exposure of a barren mineral substrate subjected to
the processes of primary colonization and soil formation. Chronosequences can be identified on
glacier moraines, where the increasing distance from the forefront corresponds to the increase of
time of permanence out of ice and to ecosystem development. Shifts of microbial and plant
communities over time are defined as succession, which can be influenced by several factors over
a forefield chronosequence. To describe the ecological succession of the microbiome composition
during primary succession of high arctic soils we identified an endemic vascular plant present in
the whole transect of the Midtre-Loveénbreen glacier, namely Saxifraga oppositifolia, and we
analyzed the associated rhizospheric communities and the corresponding bulk soils.
In the present study we applied cultivation-independent methods to investigate (i) the role of
successional stages and (ii) the influence of the host plant on the microbial community inhabiting
both bulk and rhizospheric soils collected from seven stations of a chronosequence on the
forefront of the Midtre-Loveénbreen glacier (78°53’N, Svalbard Islands, Norway), distinguished
by increasing levels of soil fertility and plant colonization (Hodkinson et al., 2003).
Detailed description of the rhizospheric microbiome realized by Denaturing Gradient Gel
Electrophoresis, 16S rRNA clone libraries and PhyloChip analyses revealed a complex bacterial
community in all the successional stages. Bulk and rhizospheric soils hosted different microbial
communities, although the rhizosphere microbiome in the youngest soils was more similar to
those of bulk soils than to the older rhizospheres. The results indicated therefore that the structure
of the bacterial communities colonizing the S. oppositifolia rhizosphere is shaped by the presence
of the plant together with the degree of soil development. The application of different molecular
methods provided us complementary information, allowing for the establishment of a huge
microbiological dataset, and indicated that the phylogenetic composition as well as ecological
indices are influenced by environmental parameters shifts along the chronosequence in a polar
desert.
Tipologia IRIS:
14 - Intervento a convegno non pubblicato
Elenco autori:
F. Mapelli, G. Tsiamis, B. Scaglia, R. Marasco, A. Balloi, E. Rolli, F. Tambone, S. Vasileiadis, F. Adani, K. Bourtzis, S. Borin, D. Daffonchio
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