Project description:Bradyrhizobia are common members of soil microbiomes and known as N2-fixing symbionts of economically important legumes. Many are also denitrifiers, which can act as sinks or sources for N2O. Inoculation with compatible rhizobia is often needed for optimal N2-fixation, but the choice of inoculant may have consequences for N2O emission. Here, we determined the phylogeny and denitrification capacity of Bradyrhizobium strains, most of them isolated from peanut-nodules. Analyses of genomes and denitrification end-points showed that all were denitrifiers, but only ~1/3 could reduce N2O. The N2O-reducing isolates had strong preference for N2O- over NO3--reduction. Such preference was also observed in a study of other bradyrhizobia and tentatively ascribed to competition between the electron pathways to Nap (periplasmic NO3- reductase) and Nos (N2O reductase). Another possible explanation is lower abundance of Nap than Nos. Here, proteomics revealed that Nap was instead more abundant than Nos, supporting the hypothesis that the electron pathway to Nos outcompetes that to Nap. In contrast, Paracoccus denitrificans, which has membrane-bond NO3- reductase (Nar), reduced N2O and NO3- simultaneously. We propose that the control at the metabolic level, favoring N2O reduction over NO3- reduction, applies also to other denitrifiers carrying Nos and Nap but lacking Nar.
Project description:Peanut allergy reaction severity correlates with increased intestinal epithelial cell (IEC) barrier permeability. CC027/GeniUnc mice develop peanut allergy by intragastric administration of peanut proteins without adjuvant. We report that peanut-allergic CC027/GeniUnc mice showed increased IEC barrier permeability and systemic peanut allergen Ara h 2 after challenge. Jejunal epithelial cell transcriptomics showed effects of peanut allergy on IEC proliferation, survival, and metabolism, and revealed IEC-predominant angiopoietin like-4 (Angptl4) as a unique feature of CC027/GeniUnc peanut allergy. Peanut-allergic pediatric patients demonstrated significantly higher serum ANGPTL4 compared to non-peanut-allergic but atopic patients, highlighting its potential as a biomarker of peanut allergy.
Project description:Peanut is one of the most important cash crops with high quality oil, high protein content, and many other nutritional elements, and grown globally. Cultivated peanut (Arachis hypogaea L.) is allotetraploid with a narrow genetic base, and its genetics and molecular mechanisms controlling the agronomic traits are poorly understood. The array SNP data was used for revaling of key candidate loci and genes associated with important agronomic traits in peanut
Project description:Peanut protein is a remarkably potent food allergen in susceptible individuals. The frequency of peanut allergy is approximately 1% in the US population. Peanut allergy often presents with severe symptoms, and it is seldom outgrown. We sought to understand how peanut protein activates human dendritic cells, which are crucial in promoting the activation and differentiation of pathogenic peanut-specific Th2 cells that drive allergic responses.
Project description:Investigation of resistance genes from 36,158 peanut ESTs after salt stress treatment, compared with untreated peanut. Yield some useful insights into salt-mediated signal transduction pathways in peanut.
Project description:Investigation of resistance genes from 36,158 peanut ESTs after cold stress treatment, compared with untreated peanut. Yield some useful insights into cold-mediated signal transduction pathways in peanut.
Project description:Peanut (Arachis hypogaea) has a large (~2.7 Gbp) allotetraploid genome with closely related component genomes making its genome very challenging to assemble. Here we report genome sequences of its diploid ancestors (A. duranensis and A. ipaënsis). We show they are similar to the peanutâs A- and B-genomes and use them use them to identify candidate disease resistance genes, create improved tetraploid transcript assemblies, and show genetic exchange between peanutâs component genomes. Based on remarkably high DNA identity and biogeography, we conclude that A. ipaënsis may be a descendant of the very same population that contributed the B-genome to cultivated peanut. Whole Genome Bisulphite Sequencing of the peanut species Arachis duranensis and Arachis ipaensis.
Project description:Intercropping is a vital technology in resource-limited agricultural systems with low inputs. Peanut/maize intercropping enhances iron (Fe) nutrition in calcareous soil. Proteomic studies of the differences in peanut leaves, maize leaves and maize roots between intercropping and monocropping systems indicated that peanut/maize intercropping not only improves Fe availability in the rhizosphere but also influences the levels of proteins related to carbon and nitrogen metabolism. Moreover, intercropping may enhance stress resistance in the peanut plant (Xiong et al. 2013b). Although the mechanism and molecular ecological significance of peanut/maize intercropping have been investigated, little is known about the genes and/or gene products in peanut and maize roots that mediate the benefits of intercropping. In the present study, we investigated the transcriptomes of maize roots grown in intercropping and monocropping systems by microarray analysis. The results enabled exploration differentially expressed genes in intercropped maize. Peanut (Arachis hypogaea L. cv. Luhua14) and maize (Zea mays L. cv. Nongda108) seeds were grown in calcareous sandy soil in a greenhouse. The soil was enhanced with basal fertilizers [composition (mg·kg−1 soil): N, 100 (Ca (NO3)2·4H2O); P, 150 (KH2PO4); K, 100 (KCl); Mg, 50 (MgSO4·7H2O); Cu, 5 (CuSO4·5H2O); and Zn, 5 (ZnSO4·7H2O)]. The experiment consisted of three cropping treatments: peanut monocropping, maize monocropping and intercropping of peanut and maize. After germination of peanut for 10 days, maize was sown. Maize samples were harvested after 63 days of growth of peanut plants based on the degree of Fe chlorosis in the leaves of monocropped peanut. The leaves of monocropped peanut plants exhibited symptoms of Fe-deficiency chlorosis at 63 days, while the leaves of peanut plants intercropped with maize maintained a green color.