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:<p>Carbonate-type saline-alkaline stress severely constrains maize production; however, the synergistic response mechanisms between rhizosphere microorganisms and metabolites remain unclear. This study focused on maize fields in the carbonate chernozem region of the Songnen Plain in Northeast China. Through field experiments and the integration of soil chemical factor analysis, microbial high-throughput sequencing (16S rRNA and ITS), and non-targeted metabolomics (LC-MS), we systematically investigated the response mechanisms of the rhizosphere micro-ecosystem under saline-alkaline stress. The results indicated that saline-alkaline stress significantly increased soil pH and electrical conductivity (EC), and led to decreases in soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) contents. However, the rhizosphere zone exhibited a certain buffering capacity, maintaining a higher cation exchange capacity (CEC). Microbial community analysis revealed that bacterial alpha diversity increased under stress. In contrast, fungal diversity significantly decreased, and the community structure shifted towards a pathogen-dominated community, primarily within Ascomycota, especially the genus Fusarium. Co-occurrence network analysis further revealed that saline-alkaline conditions enhanced the complexity and connectivity of bacterial networks but led to the contraction and structural simplification of fungal networks. Metabolite analysis showed that saline-alkaline stress induced significant reprogramming of the rhizosphere metabolic profile. Organophosphorus compounds, nucleotides, and their analogs were significantly enriched, while defensive secondary metabolites such as Cajanol specifically accumulated in the saline-alkaline rhizosphere. Pathway analysis indicated the activation of stress resistance and oxidative stress mitigation-related pathways, including Betalain biosynthesis, flavonoid biosynthesis, tryptophan metabolism, and arginine metabolism. Multi-omics integration analysis identified soil EC and total potassium (TK) as key environmental factors driving the differentiation of microbial and metabolite communities. Key differential metabolites showed significant positive correlations with saline-alkaline-enriched microbial taxa (e.g., Sphingomonas), revealing a metabolite-mediated microbial recruitment mechanism. This study, through multi-omics analysis, discovered that the maize rhizosphere, under saline-alkaline stress, undergoes metabolic reprogramming (e.g., enriching defensive metabolites like Cajanol) to directionally recruit beneficial bacteria such as Sphingomonas and maintains higher bacterial network complexity, while also leading to the pathologization of the fungal community. Our study reveals that maize recruits beneficial microbes via rhizosphere metabolic reprogramming, providing a mechanistic basis for microbiome-assisted saline-alkaline soil remediation.</p>
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.
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.
Project description:Cover cropping is an effective method to protect agricultural soils from erosion, promote nutrient and moisture retention, encourage beneficial microbial activity, and maintain soil structure. Reusing winter cover crop root channels with the maize roots during the summer allows the cash crop to extract resources from farther niches in the soil horizon. In this study, we investigate how reusing winter cover crop root channels to grow maize (Zea mays L.) affects the composition and function of the bacterial communities in the rhizosphere using 16S rRNA gene amplicon sequencing and metaproteomics. We discovered that the bacterial community significantly differed among cover crop variations, soil profile depths, and maize growth stages. Re-usage of the root channels increased bacterial abundance, and it further increases as we elevate the complexity from monocultures to mixtures. Upon mixing legumes with brassicas and grasses, the overall expression of several steps of the carbon cycle (C) and the nitrogen cycle (N) improved. The deeper root channels of legumes and brassicas compared to grasses correlated with higher bacterial 16S rRNA gene copy numbers and community roles in the respective variations in the subsoil regimes due to the increased availability of root exudates secreted by maize roots. In conclusion, root channel re-use (monocultures and mixtures) improved the expression of metabolic pathways of the important C and N cycles, and the bacterial communities, which is beneficial to the soil rhizosphere as well as to the growing crops.
2025-05-02 | PXD046832 | Pride
Project description:Fungal community structure in rhizosphere soil
| PRJNA1000730 | ENA
Project description:Bacterial community structure in maize rhizosphere soil