Project description:MicroRNAs (miRNAs) are a class of endogenous small RNAs that play important roles in growth, development, and environmental stress response processes in plants. Ulmus pumila is a typical deciduous broadleaved tree species of north temperate, and is widely distributed in central and northern Asia, which has important economic and ecological value. With the spread and aggravate of soil salinisation, salt stress has become a major abiotic stress that highly affects the normal growth and development of U. pumila. However, to date, no investigation into the influence of salt stress on U. pumila miRNAs has been reported. To identify miRNAs and predict their target mRNA genes under salt stress, three small RNA libraries were generated and sequenced from CK (without salt stress), LSS (light salt stress for a short time) and MSL (medium-heavy salt stress for a long time) roots of U. pumila seedlings. Through integrative analysis, 245 conserved miRNAs representing 30 families and 64 novel miRNAs were identified, of which 89 exhibited altered expression level under salt stress, and 232 potential targets for the miRNAs were predicted and annotated in U. pumila. The expressions of six differentially expressed miRNAs were validated by qRT-PCR. These salt responsive miRNAs may play crucial roles in U. pumila defense against salt stress, and our miRNA data provides valuable information regarding further functional analysis of miRNAs involved in salt tolerance of U. pumila and other forest tree species.
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: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: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.