Project description:Understanding the environmental factors that shape microbial communities is crucial, especially in extreme environments, like Antarctica. Two main forces were reported to influence Antarctic soil microbes: birds and plants. Both birds and plants are currently undergoing unprecedented changes in their distribution and abundance due to global warming. However, we need to clearly understand the relationship between plants, birds and soil microorganisms. We therefore collected rhizosphere and bulk soils from six different sampling sites subjected to different levels of bird influence and colonized by Colobanthus quitensis and Deschampsia antarctica in the Admiralty Bay, King George Island, Maritime Antarctic. Microarray and qPCR assays targeting 16S rRNA genes of specific taxa were used to assess microbial community structure, composition and abundance and analyzed with a range of soil physico-chemical parameters. The results indicated significant rhizosphere effects in four out of the six sites, including areas with different levels of bird influence. Acidobacteria were significantly more abundant in soils with little bird influence (low nitrogen) and in bulk soil. In contrast, Actinobacteria were significantly more abundant in the rhizosphere of both plant species. At two of the sampling sites under strong bird influence (penguin colonies), Firmicutes were significantly more abundant in D. antarctica rhizosphere but not in C. quitensis rhizosphere. The Firmicutes were also positively and significantly correlated to the nitrogen concentrations in the soil. We conclude that the microbial communities in Antarctic soils are driven both by bird and plants, and that the effect is taxa-specific.

2012-06-01 | GSE33847 | GEO

Evaluation of Edaphic Microbial Ammonium Oxidizing Communities during a Yellow Potato Cycle Culture

Project description:This study evaluated the ammonium oxidizing communities (COA) associated with a potato crop (Solanum phureja) rhizosphere soil in the savannah of Bogotá (Colombia) by examining the presence and abundance of amoA enzyme genes and transcripts by qPCR and next-generation sequence analysis. amoA gene abundance could not be quantified by qPCR due to problems inherent in the primers; however, the melting curve analysis detected increased fluorescence for Bacterial communities but not for Archaeal communities. Transcriptome analysis by next-generation sequencing revealed that the majority of reads mapped to ammonium-oxidizing Archaea, suggesting that this activity is primarily governed by the microbial group of the Crenarchaeota phylum. In contrast,a lower number of reads mapped to ammonia-oxidizing bacteria.

2018-08-06 | GSE71824 | GEO

Transcription profiling by array of Pseudomonas aeruginosa in a rhizopsphere during phosphate limitation conditions

Project description:Plants and rhizosphere microbes rely closely on each other, with plants supplying carbon to bacteria in root exudates, and bacteria mobilizing soil-bound phosphate for plant nutrition. When the phosphate supply becomes limiting for plant growth, the composition of root exudation changes, affecting rhizosphere microbial communities and microbially-mediated nutrient fluxes. To evaluate how plant phosphate deprivation affects rhizosphere bacteria, Lolium perenne seedlings were root-inoculated with Pseudomonas aeruginosa 7NR, and grown in axenic microcosms under different phosphate regimes (330 uM vs 3-6 uM phosphate). The effect of biological nutrient limitation was examined by DNA microarray studies of rhizobacterial gene expression.

2011-07-01 | E-MEXP-2812 | biostudies-arrayexpress

GeoChip data of soil microbial communities in the maize rhizosphere and bulk soils

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. Triplicate samples were taken for both rhizosphere and bulk soil, in which each individual sample was a pool of four plants or soil cores. To determine the abundance of functional genes in the rhizosphere and bulk soils, GeoChip 3.0 was used.

2014-09-12 | E-GEOD-61338 | biostudies-arrayexpress

GeoChip data of soil microbial communities in the maize rhizosphere and bulk soils

2014-12-10 | E-MTAB-2920 | biostudies-arrayexpress

Transcriptome of Moesziomyces albugensis in response to different biotic factors (A. laibachii & SynCom) on A. thaliana leaves

Project description:As the phyllosphere is a resource-limited niche, microbes have evolved different survival strategies by collaborating or competing with other organisms. This leads to the establishment of network structures which are stabilised by so-called microbial hub organisms. An already identified hub in the Arabidopsis thaliana phyllosphere is the oomycete pathogen Albugo laibachii. From wild Arabidopsis plants with white rust symptoms we isolated the basidiomycete yeast Moesziomyces albugensis, which is closely related to plant pathogenic smut fungi. It suppresses the infection of A. laibachii in lab experiments and inhibits growth of several bacterial phyllosphere members. The transcriptomic response of M. albugensis to presence of A. laibachii and bacterial SynCom members was investigated by using RNA sequencing. Interestingly, several genes encoding secretory proteins, mostly glycoside hydrolases and peptidases, are particularly induced upon interaction with A. laibachii.

2021-01-15 | GSE148670 | GEO

Phyllosphere bacterial communities of beech (Fagus sylvatica) along an elevation gradient

Project description:Phyllosphere bacterial communities

| PRJEB8017 | ENA