Project description:The rhizosphere is a small region surrounding plant roots that is enriched in biochemicals from root exudates and populated with fungi, nematode, and bacteria. Interaction of rhizosphere organisms with plants is mainly promoted by exudates from the roots. Root exudates contain biochemicals that come from primary and secondary metabolisms of plants. These biochemicals attract microbes, which influence plant nutrition. The rhizosphere bacteria (microbiome) are vital to plant nutrient uptake and influence biotic and abiotic stress and pathogenesis. Pseudomonas is a genus of gammaproteobacteria known for its ubiquitous presence in natural habitats and its striking ecological, metabolic, and biochemical diversity. Within the genus, members of the Pseudomonas fluorescens group are common inhabitants of soil and plant surfaces, and certain strains function in the biological control of plant disease, protecting plants from infection by soilborne and aerial plant pathogens. The soil bacterium Pseudomonas protegens Pf-5 (also known as Pseudomonas fluorescens Pf-5) is a well-characterized biological strain, which is distinguished by its prolific production of the secondary metabolite, pyoverdine. Knowledge of the distribution of P. fluorescens secretory activity around plant roots is very important for understanding the interaction between P. fluorescens and plants and can be achieved by real time tracking of pyoverdine. To achieve the capability of real-time tracking in soil, we have used a structure-switching SELEX strategy to select high affinity ssDNA aptamers with specificity for pyoverdine over other siderophores. Two DNA aptamers were isolated, and their features compared. The aptamers were applied to a nanoporous aluminum oxide biosensor and demonstrated to successfully detect PYO-Pf5. This sensor provides a future opportunity to track the locations around plant roots of P. protegens and to monitor PYO-Pf5 production and movement through the soil.
Project description:For shade-intolerant species, shade light indicates the close proximity of neighboring plants and triggers the shade avoidance syndrome (SAS), which causes exaggerated growth and reduced crop yield. We report that microbiotal root commensals(Pseudomonas fluorescens and Root918) alleviate the shade avoidance responses in Arabidopsis. To identify the functions of Pseudomonas fluorescens and Root918 during SAS, we performed RNA-seq to search for differentially expressed genes (DEGs) in different tissues by comparing the transcript levels of shoot and root parts of col0 in germ-free, Pseudomonas fluorescens and Root918 during white light and shade conditions.
Project description:Whole genome gene expression study comparing Pseudomonas fluorescens Pf0-1 (Wt) relative to a delta-pst mutant (deletion of the pstSCAB operon) that consitutively expresses the Pho regulon Mutants used in this study are further described in Monds, R.D. Newell, P.D., Gross, R.H., O'Toole, G.A. (2007) Phosphate-dependent modulation of c-di-GMP levels regulates Pseudomonas fluorescens Pf0-1 biofilm formation by controlling secretion of the adhesin LapA. Mol. Microbiol. 63(3): 656-679 A four chip study using total RNA recovered from two independent wild-type cultures of wild type strain Pseudomonas fluorescens Pf0-1 and two independent cultures of Pseudomonas fluorescens Pf0-1 delta pst mutant (deletion of the pstSCAB operon). Each chip measures the expression level of 5733 open reading frames (ORFs) genes from Pseudomonas fluorescens Pf0-1 (Refseq: NC_007492) with twenty 60-mer postive match (PM) probes per gene, with three-fold technical redundancy.
Project description:This SuperSeries is composed of the following subset Series: GSE29319: Iron-starvation effect on transcriptome of Pseudomonas fluorescens Pf-5: iron(II) chloride GSE29320: Iron-starvation effect on transcriptome of Pseudomonas fluorescens Pf-5: iron(III) chloride Refer to individual Series
Project description:This SuperSeries is composed of the following subset Series: GSE33907: Tannic acid (20 µg/ mL) treatment effect on transcriptome of Pseudomonas fluorescens Pf-5 GSE33908: Tannic acid (160 µg/ mL) treatment effect on transcriptome of Pseudomonas fluorescens Pf-5 Refer to individual Series