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.
Project description:Phosphate (P) fertilization impacts many rhizosphere processes, driving plant P use efficiency. However, less is known about the induced molecular and physiological root-rhizosphere traits in responses to polyphosphates (PolyP), particularly root transcriptome and belowground functional traits responsible for P acquisition. The present study aims to investigate physiological and transcriptomic belowground mechanisms explaining the enhanced durum wheat P acquisition under PolyP (PolyB and PolyC) supply. Root molecular traits were differentially expressed in response to PolyP, where PolyB induced upregulation of OGDH, MDH, and ENO, PAP21 and downregulation of PFK, and LDH genes. The modulation of gene expression can presumably explain the PolyP-induced changes in rhizosphere (root, rhizosphere soil, soil solution) acidification (pH decreased from 8 to 6.3) and acid phosphatase activities, which were concomitant with enhanced rhizosphere soil P availability and shoot Pi content (145% and 36% compared to OrthoP, respectively) along with changes in morphological and transcriptomic root (particularly, the upregulation of AUX1 and ABA transporter genes) traits. These findings provide novel insights that P acquisition from polyphosphates involves the coordinated regulation of genes governing root-rhizosphere processes and root development, ultimately enhancing wheat P acquisition.
2025-05-31 | GSE277488 | GEO
Project description:Fungal community structure in sugarcane cultivated area affected by root rot
Project description:Considering the crucial role of root exudates, we hypothesized that continuous wheat cultivation would lead to lower glucose release, resulting in lower microbial growth, activity, and biomass. For the first time in situ glucose imaging was optimized for studying the interactions in the first (W1) and third (W3) wheat after break crop plots in the field. Glucose imaging method combined with soil microbial respiration, enzyme kinetics and the quantification SWEET genes expression levels in wheat plants. W3 had the lowest proportion of hotspots for glucose release with 1.35 % of the total soil surface area, indicating a 17.7 % decline compared to W1. Also, the expressions of functional orthologous genes of SWEET1a in wheat roots were significantly upregulated in W3 compared to W1. The growing microbial biomass in the rhizosphere soil of W1 was about five times higher than W3. Differences in SWEET gene expression and shift in glucose release is linked to altered root physiology and exudation processes, potentially reflecting the plant's strategy to create a less favourable environment for opportunistic pathogens. Hence, this study provides novel insights into the complex interactions between continuous wheat cultivation, root exudation, microbial dynamics, gene expression, and enzymatic activities.
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.
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. The results of microarray analyses indicated that atmospheric elevated CO2 concentration indirectly influences on expression of large number of Bradyrhizobium genes through soybean roots. In addition, genes involved in C1 metabolism, denitrification and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2 in the rhizosphere, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency.
Project description:Interaction of microbes affects the growth, metabolism and differentiation of members of the community. While direct and indirect competitions, like spite and nutrient consumption have negative effect on each other, microbes also evolved in nature not only to fight, but in some cases to adapt or support each other while increasing the fitness of the community. Presence of bacteria and fungi in the soil results in interactions and various examples were described, including mutualism. Bacilli attach to the plant root and form complex communities in the rhizosphere. Bacillus subtilis, when grown in the presence of Aspergillus niger interacts with the fungal partner, attaches and grows on the hyphae. Using dual transcriptome experiment, we show that both fungi and bacteria alter their metabolisms during the interaction. Interestingly, the transcription of genes related to the antifungal and antibacterial defense mechanism of B. subtilis and A. niger, respectively, are decreased upon attachment of bacteria to the mycelia. Our microarray experiments provide a novel insight into the mutual interaction of a bacterium and a fungus. Aspergillus niger were grown with and without Bacillus subtilis. Biological triplicates were made for both conditions, Affymetrix microarray experiments were performed on these samples.
Project description:Interaction of microbes affects the growth, metabolism and differentiation of members of the community. While direct and indirect competitions, like spite and nutrient consumption have negative effect on each other, microbes also evolved in nature not only to fight, but in some cases to adapt or support each other while increasing the fitness of the community. Presence of bacteria and fungi in the soil results in interactions and various examples were described, including mutualism. Bacilli attach to the plant root and form complex communities in the rhizosphere. Bacillus subtilis, when grown in the presence of Aspergillus niger interacts with the fungal partner, attaches and grows on the hyphae. Using dual transcriptome experiment, we show that both fungi and bacteria alter their metabolisms during the interaction. Interestingly, the transcription of genes related to the antifungal and antibacterial defense mechanism of B. subtilis and A. niger, respectively, are decreased upon attachment of bacteria to the mycelia. Our microarray experiments provide a novel insight into the mutual interaction of a bacterium and a fungus.