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Rhizosphere heterogeneity shapes abundance and activity of sulfur-oxidizing bacteria in vegetated salt marsh sediments
- Source :
- Frontiers in Microbiology, Vol 5 (2014), Frontiers in Microbiology, Frontiers in Microbiology, Frontiers Media, 2014, 5, pp.309. ⟨10.3389/fmicb.2014.00309⟩
- Publication Year :
- 2014
- Publisher :
- Frontiers Media S.A., 2014.
-
Abstract
- International audience; Salt marshes are highly productive ecosystems hosting an intense sulfur (S) cycle, yet little is known about S-oxidizing microorganisms in these ecosystems. Here, we studied the diversity and transcriptional activity of S-oxidizers in salt marsh sediments colonized by the plant Spartina alterniflora, and assessed variations with sediment depth and small-scale compartments within the rhizosphere. We combined next-generation amplicon sequencing of 16S rDNA and rRNA libraries with phylogenetic analyses of marker genes for two S-oxidation pathways (soxB and rdsrAB). Gene and transcript numbers of soxB and rdsrAB phylotypes were quantified simultaneously, using newly designed (RT)-qPCR assays. We identified a diverse assemblage of S-oxidizers, with Chromatiales and Thiotrichales being dominant. The detection of transcripts from S-oxidizers was mostly confined to the upper 5 cm sediments, following the expected distribution of root biomass. A common pool of species dominated by Gammaproteobacteria transcribed S-oxidation genes across roots, rhizosphere, and surrounding sediment compartments, with rdsrAB transcripts prevailing over soxB. However, the root environment fine-tuned the abundance and transcriptional activity of the S-oxidizing community. In particular, the global transcription of soxB was higher on the roots compared to mix and rhizosphere samples. Furthermore, the contribution of Epsilonproteobacteria-related S-oxidizers tended to increase on Spartina roots compared to surrounding sediments. These data shed light on the under-studied oxidative part of the sulfur cycle in salt marsh sediments and indicate small-scale heterogeneities are important factors shaping abundance and potential activity of S-oxidizers in the rhizosphere.
- Subjects :
- Microbiology (medical)
Microorganism
lcsh:QR1-502
Spartina alterniflora
Microbiology
Sulfur oxidation
lcsh:Microbiology
Botany
Gammaproteobacteria
Ecosystem
Original Research Article
geography
Rhizosphere
Spartina
geography.geographical_feature_category
biology
Ecology
Sulfur cycle
soxB
15. Life on land
biology.organism_classification
rdsrAB
salt marsh
Salt marsh
[SDE]Environmental Sciences
rhizosphere
Subjects
Details
- Language :
- English
- ISSN :
- 1664302X
- Volume :
- 5
- Database :
- OpenAIRE
- Journal :
- Frontiers in Microbiology
- Accession number :
- edsair.doi.dedup.....b23c050699185ad2075fd8c279aaf2c4