Project description:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
Project description:Cotton (Gossypium hirsutum L.) is one of the most important cash crops worldwide. In semi-arid/arid regions, drought stress causes growth limitation and decrease of yield. Of all the organs of a plant, fine root is the central part consisting of the root system to contribute to plant water and nutrient taken up. However, the research on the molecular mechanism underlying fine root response to soil drought has not been well understood in cotton. To better characterize the proteomic changes of cotton fine roots under drought stress, 70±5% and 40±5% soil relative water content were designed as control (CK) and drought stress (DS) groups, respectively. Tandem mass tags (TMT) technology was used to determine the proteome profiles in fine roots. The proteomic differences between CK and DS were pairwise compared at 0, 30, and 45 days after drought stress (DAD). A total of 11,628 proteins were identified, of which 10,344 proteins contained quantitative information. According to the morphological, physiological, and biochemical characteristics, 30 and 45 DAD were selected as critical stages for further analysis. Results showed that 118 differentially expressed proteins (DEPs) were up-regulated and 105 down-regulated in DS 30 versus CK 30; 662 DEPs were up-regulated, and 611 were down-regulated in DS 45 versus CK 45. The DEP functions were determined for their classified pathways, mainly associated with carbohydrate metabolism, energy metabolism, fatty acid metabolism, amino acid metabolism, and secondary metabolite biosynthesis. DEPs related to phytohormone and stress/defense response were also identified. To verify the accuracy of the TMT results, 20 DEPs were randomly selected for parallel reaction monitoring (PRM) verification. And results showed that the quantitative results of TMT are consistent with those of PRM, which proved that the TMT results of this study are reliable. In this article we describe changes in the protein profiles occurring in response to drought stress in cotton fine roots. Proteomic analyses of plant responses to stressors could lead to the introduction of cotton cultivars with high resistance to drought stress. Such plants would be valuable for high yielding under drought as well as other unfavorable environmental conditions.
2020-06-24 | PXD017736 | Pride
Project description:Soil fungal community structure under the addition treatments of different root exudates
| PRJNA1005408 | ENA
Project description:Soil bacterial community structure under the addition treatments of different root exudates
Project description:Arsenic (As) bioavailability in the rice rhizosphere is influenced by many microbial interactions, particularly by metal-transforming functional groups at the root-soil interface. This study was conducted to examine As-transforming microbes and As-speciation in the rice rhizosphere compartments, in response to two different water management practices (continuous and intermittently flooded), established on fields with high to low soil-As concentration. Microbial functional gene composition in the rhizosphere and root-plaque compartments were characterized using the GeoChip 4.0 microarray. Arsenic speciation and concentrations were analyzed in the rhizosphere soil, root-plaque, porewater and grain samples. Results indicated that intermittent flooding significantly altered As-speciation in the rhizosphere, and reduced methyl-As and AsIII concentrations in the pore water, root-plaque and rice grain. Ordination and taxonomic analysis of detected gene-probes indicated that root-plaque and rhizosphere assembled significantly different metal-transforming functional groups. Taxonomic non-redundancy was evident, suggesting that As-reduction, -oxidation and -methylation processes were performed by different microbial groups. As-transformation was coupled to different biogeochemical cycling processes establishing functional non-redundancy of rice-rhizosphere microbiome in response to both rhizosphere compartmentalization and experimental treatments. This study confirmed diverse As-biotransformation at root-soil interface and provided novel insights on their responses to water management, which can be applied for mitigating As-bioavailability and accumulation in rice grains.
Project description:For environmental safety, the high concentration of heavy metals in the soil should be removed. Cadmium (Cd), one of the heavy metals polluting the soil while its concentration exceeds 3.4 mg/kg in soil. Potential use of cotton for remediating heavy Cd-polluted soils is available while its molecular mechanisms of Cd tolerance remains unclear in cotton. In this study, transcriptome analysis was used to identify the Cd tolerance genes and their potential mechanism in cotton. Finally 4,627 differentially expressed genes (DEGs) in the root, 3,022 DEGs in the stem and 3,854 DEGs in leaves were identified through RNA-Seq analysis, respectively. These genes contained heavy metal transporter genes (ABC, CDF, HMA, etc.), annexin genes, heat shock genes (HSP) amongst others. Gene ontology (GO) analysis showed that the DEGs were mainly involved in the oxidation-reduction process and metal ion binding. The DEGs mainly enriched in two pathways, the influenza A and the pyruvate pathway. GhHMAD5 protein, containing a heavy-metal domain, was identified in the pathway to transport or to detoxify the heavy ion. GhHMAD5-overexpressed plants of Arabidopsis thaliana showed the longer roots compared with the control. Meanwhile, GhHMAD5-silenced cotton plants showed more sensitive to Cd stress compared with the control. The results indicated that GhHMAD5 gene is remarkably involved in Cd tolerance, which gives us a preliminary understanding of Cd tolerance mechanisms in upland cotton. Overall, this study provides valuable information for the use of cotton to remediate the soil polluted with heavy metals.
Project description:Transcriptome analysis in cotton under drought stress. To study the molecular response of drought stress in cotton under field condition global gene expression analysis was carried out in leaf tissue. Gossypium hirsutum cv. Bikaneri Nerma was used for the gene expression analysis. Cotton plants were subjected to drought stress at peak flowering stage. Leaf samples were collected when the soil moisture content was 19.5% which is 50% of the normal control plots. Gene expression profiles in drought induced and their respective control samples were analyzed using Affymertix cotton Genechip Genome arrays to study the global changes in the expression of genome.
Project description:Five allotetraploid cotton species have adapted, through their transcriptional responses, to unique environments with distinct levels of inherent abiotic stresses. The transcriptional responses of leaf and root tissue in five allotetraploid cotton species (Gossypium hirsutum, G. barbadense, G. tomentosum, G. mustelinum, and G. darwinii) under salt stress have been investigated in this study using cotton long oligonucleotide microarrays. Physiological responses to salinity such as stomatal conductance, ion and osmoprotectant contents were also measured as indicators of imposed stress. Accessions from these five cotton species were hydroponically grown and gradually introduced to a NaCl treatment (15 dS m-1). The microarray results identified 2721 and 2460 differentially expressed genes under salt stress that were significant in leaf and root tissue, respectively. Many of these genes were classified under gene ontology (GO) categories that suggest abiotic stress. These allotetraploid cottons shared transcriptional responses to salinity, but also showed responses that were species-specific. No consistent differences in transcriptional response among the previously estimated phylogenetic branches were found. Stomatal conductance, ion accumulation, and betaine, trigonelline, and trehalose contents also indicated salt stress. This global assessment of transcriptional and physiological responses to salt stress of these cotton species may identify possible gene targets for crop improvement and evolutionary studies of cotton. Keywords: CEGC Cotton oligo salt stress
Project description:Transcriptome analysis was performed on the rhizome tissues of Atractylodes macrocephala under different treatments. The four treatments were: sterile water irrigation alone, FS root irrigation, FS and AM201 root irrigation, and FS combined with methyltobuzin (TM) root irrigation. And the differential genes between AM201 and FO groups were identified and compared, which helps to reveal the resistance mechanism of AM201 to Atractylodes macrocephala root rot disease