Project description:Arsenic (As) bioavailability in the rice rhizosphere is influenced by many microbial interactions, particularly by metal-transforming functional groups at the root-soil interface. This study was conducted to examine As-transforming microbes and As-speciation in the rice rhizosphere compartments, in response to two different water management practices (continuous and intermittently flooded), established on fields with high to low soil-As concentration. Microbial functional gene composition in the rhizosphere and root-plaque compartments were characterized using the GeoChip 4.0 microarray. Arsenic speciation and concentrations were analyzed in the rhizosphere soil, root-plaque, porewater and grain samples. Results indicated that intermittent flooding significantly altered As-speciation in the rhizosphere, and reduced methyl-As and AsIII concentrations in the pore water, root-plaque and rice grain. Ordination and taxonomic analysis of detected gene-probes indicated that root-plaque and rhizosphere assembled significantly different metal-transforming functional groups. Taxonomic non-redundancy was evident, suggesting that As-reduction, -oxidation and -methylation processes were performed by different microbial groups. As-transformation was coupled to different biogeochemical cycling processes establishing functional non-redundancy of rice-rhizosphere microbiome in response to both rhizosphere compartmentalization and experimental treatments. This study confirmed diverse As-biotransformation at root-soil interface and provided novel insights on their responses to water management, which can be applied for mitigating As-bioavailability and accumulation in rice grains.
Project description:Rhizosphere is a complex system of interactions between plant roots, bacteria, fungi and animals, where the release of plant root exudates stimulates bacterial density and diversity. However, the majority of the bacteria in soil results to be unculturable but active. The aim of the present work was to characterize the microbial community associated to the root of V. vinifera cv. Pinot Noir not only under a taxonomic perspective, but also under a functional point of view, using a metaproteome approach. Our results underlined the difference between the metagenomic and metaproteomic approach and the large potentiality of proteomics in describing the environmental bacterial community and its activity. In fact, by this approach, that allows to investigate the mechanisms occurring in the rhizosphere, we showed that bacteria belonging to Streptomyces, Bacillus and Pseudomonas genera are the most active in protein expression. In the rhizosphere, the identified genera were involved mainly in phosphorus and nitrogen soil metabolism.
Project description:Cropping soils vary in extent of natural suppression of soil-borne plant diseases. However, it is unknown whether similar variation occurs across pastoral agricultural systems. We examined soil microbial community properties known to be associated with disease suppression across 50 pastoral fields varying in management intensity. The composition and abundance of the disease-suppressive community were assessed from both taxonomic and functional perspectives.
Project description:Microbial communities in the rhizosphere make significant contributions to crop health and nutrient cycling. However, their ability to perform important biogeochemical processes remains uncharacterized. Important functional genes, which characterize the rhizosphere microbial community, were identified to understand metabolic capabilities in the maize rhizosphere using GeoChip 3.0-based functional gene array method.
2014-09-12 | GSE61338 | GEO
Project description:Tomaoto rhizosphere bacterial community composition
Project description:Purpose: This study aims to compare and analyze the differences in bacterial community composition in fecal samples from mice treated with Control(DW), Vancomycin (VAN), Ampicillin (AMP), Neomycin (NEO), Metronidazole (MET), and a combination of all antibiotics (ALL, VANM) using 16S rRNA sequencing. Methods: Each antibiotics treated mice's fecal samples were collected and stored -80'c until analyzation. DNA was extracted using the NucleoSpin DNA Stool Kit (MACHEREY-NAGEL) following the manufacturer’s protocol. Metagenomic sequencing was performed on an Illumina MiSeq platform (Illumina), targeting the V3 and V4 regions of the 16S rRNA gene according to the manufacturer's instructions. PCR products were purified using AMPure XP beads, and sequencing adapters were added using the Nextera XT Index Kit (Illumina). The library was further purified with AMPure XP beads and quantified using automated electrophoresis with the TapeStation System (Agilent). Sequencing was performed using the MiSeq v3 reagent kit (Illumina), following the manufacturer’s protocol. Results: QIIME2 (v2023.02) was used to process and analyze 16S rRNA gene amplicon sequencing data, from sequence preprocessing to taxonomic classification. Paired-end sequences were merged and quality-filtered using Deblur. The resulting amplicon sequence variants (ASVs) were used for downstream analyses. Conclusions: Our study presents a comparative analysis of bacterial community composition in fecal samples from antibiotic-treated mice. We observed that microbiota composition varied distinctly depending on the type of antibiotic administered.