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:In this study, we used the illumina high throughput sequencing approach (Sequencing-By-Synthesis, or SBS) to develop the sequence resource of black pepper. To identify micro RNAs functioning in stress response of the black pepper plant, small RNA libraries were prepared from the leaf and root of Phytophthora capsici infected plants, leaves from drought stressed and control plants.
Project description:The experiments were performed to elucidate the enigmatic enzymatic formation of the pungent principle, piperine, from black pepper (Piper nigrum L.), the world´s most popular spice. Based a differential RNA-Seq approach including immature fruits, flowers, and leaves, the gene encoding piperine synthase, encoding a BAHD-type acyltransferase and several other candidate genes encoding various enzymatic functions in the biosynthetic pathway were identified. Recombinant piperine synthase and additional promiscuous piperamide synthases were used to facilitate the microbial production of a broad range of medicinally relevant piperamides. Subsequent investigations will also include the identification of enzymatic steps in the phenylpropanoid pathway and the amino acid derived biosynthesis of piperidine Based on the assumption that piperine encoding genes are highly expressed shortly before the slope of piperine accumulation reaches its maximum, RNA from greenhouse grown black pepper plants was extracted from young fruits at two different stages of development, flowers, and leaves were harvested for a differential RNA-Seq approach. Candidate transcripts associated with piperine biosynthesis were identified by comparative transcript abundance and sequence annotation tools.
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. 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:In this study, we have evaluated the proteomic changes that occur in Piper nigrum L.(black pepper) after infection by the pathogen Phytophthora capsici. We report novel leaf proteins from black pepper identified by an integrated transcriptome-assisted label-free quantitative proteomics pipeline. Several previously described methods were used to create this data set. Detached leaves were inoculated with either mock treatment, or the oomycete pathogen and small tissue samples only around the site of inoculation were collected for protein sample preparations. In order to quantify protein abundance in the samples being compared, we used a label free method of spiking samples with a known ratio of pre-digested peptide samples to normalize endogenous protein abundance in the MS detection. Our study attempts to explain the basal immune components of black pepper when challenged with P. capsici.