Project description:We used wheat as rotational crop to assess the influence of continuous cropping on microbiome in Pinellia ternata rhizosphere and the remediation of rotational cropping to the impacted microbiota. Illumina high-throughput sequencing technology was utilized for this method to explore the rhizosphere microbial structure and diversity based on continuous and rotational cropping.
2016-12-10 | GSE91083 | GEO
Project description:Impact of soil microbial amendments on tomato rhizosphere microbiome
Project description:Bacterial wilt caused by Ralstonia solanacearum is a lethal, soil-borne disease of tomato. Control of the disease with chemicals and crop rotation is insufficient, because the pathogen is particularly well adapted for surviving in the soil and rhizosphere. Therefore, cultivar resistance is the most effective means for controlling bacterial wilt, but the molecular mechanisms of resistance responses remain unclear. We used microarrays to obtain the characteristics of the gene expression changes that are induced by R. solanacearum infection in resistant cultivar LS-89 and susceptible cultivar Ponderosa.
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.
Project description:Root exudates contain specialised metabolites that affect the plant’s root microbiome. How host-specific microbes cope with these bioactive compounds, and how this ability shapes root microbiomes, remains largely unknown. We investigated how maize root bacteria metabolise benzoxazinoids, the main specialised metabolites of maize. Diverse and abundant bacteria metabolised the major compound in the maize rhizosphere MBOA and formed AMPO. AMPO forming bacteria are enriched in the rhizosphere of benzoxazinoid-producing maize and can use MBOA as carbon source. We identified a novel gene cluster associated with AMPO formation in microbacteria. The first gene in this cluster, bxdA encodes a lactonase that converts MBOA to AMPO in vitro. A deletion mutant of the homologous bxdA genes in the genus Sphingobium, does not form AMPO nor is it able to use MBOA as a carbon source. BxdA was identified in different genera of maize root bacteria. Here we show that plant-specialised metabolites select for metabolisation-competent root bacteria. BxdA represents a novel benzoxazinoid metabolisation gene whose carriers successfully colonize the maize rhizosphere and thereby shape the plant’s chemical environmental footprint
Project description:Global food production is reliant on the application of finite phosphorus (P) fertilisers. Numerous negative consequences associated with intensive P fertilisation have resulted in a high demand to find alternative sustainable methods that will enhance crop P uptake. Bacteroidetes, primarily from the genus Flavobacterium, have recently been shown to be abundant members of the plant microbiome, but their general ecological role and potential to mobilise P in the rhizosphere remains very poorly characterised. Here, we sought to determine the P mobilisation potential of Flavobacterium strains isolated from the rhizosphere of oilseed rape (Brassica napus L.). In contrast to other abundant rhizosphere bacteria, such as Pseudomonas, all Flavobacterium strains exhibited constitutive phosphatase activity independent of external phosphate (Pi) concentrations. Interestingly, a combination of exoproteomic analysis and molecular microbiology techniques revealed that Flavobacterium have a complex and largely unique repertoire of proteins to mobilise and acquire Pi. This includes the expression of novel, as yet unidentified, phosphatases, and numerous proteins of unknown function. We also discovered that Flavobacterium expresses certain SusCD-like transporters, whose role is typically associated with specialised carbon acquisition, in response to Pi-starvation. Furthermore, the genes encoding these unusual Pi-responsive proteins were enriched in plant-associated Flavobacterium strains suggesting that this machinery represents niche-adaptive strategies for overcoming P scarcity in this genus. We propose that abundant rhizosphere-dwelling Flavobacterium spp. have evolved unique mechanisms for coping with Pi-stress which may provide novel solutions for future sustainable agricultural practices.
2021-09-08 | PXD014380 | Pride
Project description:Metagenomic insight into bacterial structure and function of rhizosphere microbiome in crop rotation system
Project description:Poplar is a short-rotation woody crop routinely studied because of its importance as a sustainable bioenergy crop. The establishment of a successful poplar plantation partially depends on its rhizosphere, a dynamic zone governed by complex interactions between plant roots and a plethora of commensal, mutualistic, symbiotic, or pathogenic microbes that shape plant fitness. Here, we examined a consortium of ectomycorrhizal fungi and a beneficial Pseudomonas sp. strain GM41 for their effect on plant growth (height, stem girth, leaf, and root growth) and growth rate over time of four poplar genotypes of Populus trichocarpa. We also compare the total organic carbon and plant exometabolites profiles produced by these different poplar genotypes when colonized by the microbial consortium. We determined that when comparing the treatments to the control, plant growth parameters were not significantly different across the poplar genotypes eight weeks post-inoculation. However, total organic carbon and exometabolite profiles were significantly different between the genotypes and due to the treatments. These findings indicate that this microbial consortium can induce early and different signaling responses in poplar.