Project description:Poplar has emerged as a model plant for better understanding cellular and molecular changes accompanying tree growth, development, and response to environment. Long-term application of different forms of nitrogen (such as [Formula: see text]-N and [Formula: see text]-N) may cause morphological changes of poplar roots; however, the molecular level changes are still not well-known. In this study, we analyzed the expression profiling of poplar roots treated by three forms of nitrogen: S1 ([Formula: see text]), S2 (NH4NO3), and S3 ([Formula: see text]) by using RNA-SEQ technique. We found 463 genes significantly differentially expressed in roots by different N treatments, of which a total of 112 genes were found to differentially express between S1 and S2, 171 genes between S2 and S3, and 319 genes between S1 and S3. A cluster analysis shows significant difference in many transcription factor families and functional genes family under different N forms. Through an analysis of Mapman metabolic pathway, we found that the significantly differentially expressed genes are associated with fermentation, glycolysis, and tricarboxylic acid cycle (TCA), secondary metabolism, hormone metabolism, and transport processing. Interestingly, we did not find significantly differentially expressed genes in N metabolism pathway, mitochondrial electron transport/ATP synthesis and mineral nutrition. We also found abundant candidate genes (20 transcription factors and 30 functional genes) regulating morphology changes of poplar roots under the three N forms. The results obtained are beneficial to a better understanding of the potential molecular and cellular mechanisms regulating root morphology changes under different N treatments.
Project description:Many recent studies have emphasized the important role of structural variation (SV) in determining human genetic and phenotypic variation. In plants, studies aimed at elucidating the extent of SV are still in their infancy. Evidence has indicated a high presence and an active role of SV in driving plant genome evolution in different plant species.With the aim of characterizing the size and the composition of the poplar pan-genome, we performed a genome-wide analysis of structural variation in three intercrossable poplar species: Populus nigra, Populus deltoides, and Populus trichocarpa We detected a total of 7,889 deletions and 10,586 insertions relative to the P. trichocarpa reference genome, covering respectively 33.2 Mb and 62.9 Mb of genomic sequence, and 3,230 genes affected by copy number variation (CNV). The majority of the detected variants are inter-specific in agreement with a recent origin following separation of species.Insertions and deletions (INDELs) were preferentially located in low-gene density regions of the poplar genome and were, for the majority, associated with the activity of transposable elements. Genes affected by SV showed lower-than-average expression levels and higher levels of dN/dS, suggesting that they are subject to relaxed selective pressure or correspond to pseudogenes.Functional annotation of genes affected by INDELs showed over-representation of categories associated with transposable elements activity, while genes affected by genic CNVs showed enrichment in categories related to resistance to stress and pathogens. This study provides a genome-wide catalogue of SV and the first insight on functional and structural properties of the poplar pan-genome.
Project description:When expressed in Escherichia coli, cytosolic poplar glutaredoxin C1 (CGYC active site) exists as a dimeric iron-sulfur-containing holoprotein or as a monomeric apoprotein in solution. Analytical and spectroscopic studies of wild-type protein and site-directed variants and structural characterization of the holoprotein by using x-ray crystallography indicate that the holoprotein contains a subunit-bridging [2Fe-2S] cluster that is ligated by the catalytic cysteines of two glutaredoxins and the cysteines of two glutathiones. Mutagenesis data on a variety of poplar glutaredoxins suggest that the incorporation of an iron-sulfur cluster could be a general feature of plant glutaredoxins possessing a glycine adjacent to the catalytic cysteine. In light of these results, the possible involvement of plant glutaredoxins in oxidative stress sensing or iron-sulfur biosynthesis is discussed with respect to their intracellular localization.
Project description:MalA is an alpha-glucosidase from the hyperthermophilic archaeon Sulfolobus solfataricus. It belongs to glycoside hydrolase family 31, which includes several medically interesting alpha-glucosidases. MalA and its selenomethionine derivative have been overproduced in Escherichia coli and crystallized in four different crystal forms. Microseeding was essential for the formation of good-quality crystals of forms 2 and 4. For three of the crystal forms (2, 3 and 4) full data sets could be collected. The most suitable crystals for structure determination are the monoclinic form 4 crystals, belonging to space group P2(1), from which data sets extending to 2.5 A resolution have been collected. Self-rotation functions calculated for this form and for the orthorhombic (P2(1)2(1)2(1)) form 2 indicate the presence of six molecules in the asymmetric unit related by 32 symmetry.
Project description:Seven commercial heparin active pharmaceutical ingredients and one commercial low molecular weight from different manufacturers were characterized with a view profiling their physicochemical properties. All heparins had similar molecular weight properties as determined by polyacrylamide gel electrophoresis (M(N), 10-11 kDa; M(W), 13-14 kDa; polydispersity (PD), 1.3-1.4) and by size exclusion chromatography (M(N), 14-16 kDa; M (W), 21-25 kDa; PD, 1.4-1.6). one-dimensional (1)H- and (13)C-nuclear magnetic resonance (NMR) evaluation of the heparin samples was performed, and peaks were fully assigned using two-dimensional NMR. The percentage of glucosamine residues with 3-O-sulfo groups and the percentage of N-sulfo groups and N-acetyl groups ranged from 5.8-7.9%, 78-82%, to 13-14%, respectively. There was substantial variability observed in the disaccharide composition, as determined by high performance liquid chromatography (HPLC)-mass spectral analysis of heparin lyase I-III digested heparins. Heparin oligosaccharide mapping was performed using HPLC following separate treatments with heparin lyase I, II, and III. These maps were useful in qualitatively and quantitatively identifying structural differences between these heparins. The binding affinities of these heparins to antithrombin III and thrombin were evaluated by using a surface plasmon resonance competitive binding assay. This study provides the physicochemical and activity characterization necessary for the appropriate design and synthesis of a generic bioengineered heparin.
Project description:Phosphorus (P) is an essential nutrient for crop production, and animal manures are rich in P. When using animal manures as alternatives to synthetic fertilizers, it is important to know the kinetics of P release from different animal manures and the forms, amounts, and dynamics of P in manure-treated soils. We chose four types of manure, viz., pig manure (PM), chicken manure (CM), dairy manure (DM), and commercial organic compost (OM), and evaluated the P release rate and availability in water solution and flooded/upland paddy soils. The WEP/total P (TP) and the water-extractable P (WEP) concentrations are highest for OM with the order: OM > PM > CM > DM. An increase in soil Olsen-P concentration was observed for the addition of manure with a varying application rate of P from low to moderate to high. The release capacity of Olsen-P in flooded conditions was higher than that in upland conditions. Under the flooded soil, PM and OM have faster release rates than CM and OM in the upland soil. Moreover, PM significantly increased available P by 29% in the flooded paddy soil while moderately inorganic P increased by 17% in the upland paddy soil. Olsen-P has a significant linear relationship with available P (Resin-P + NaHCO3-Pi; R 2 = 0.104; P < 0.01) and moderately inorganic P (NaOH-Pi + HCl-P; R 2 = 0.286; P < 0.01). The structural equation model showed that the organic input was beneficial to the conversion of moderately inorganic P to available P. Our results indicate that PM amendment promotes the release of available P in paddy soil.
Project description:Vitreoscilla filiformis is a Gram-negative bacterium isolated from spa waters and described for its beneficial effects on the skin. We characterized the detailed structure of its lipopolysaccharide (LPS) lipid A moiety, an active component of the bacterium that contributes to the observed skin activation properties. Two different batches differing in postculture cell recovery were tested. Chemical analyses and mass spectra, obtained before and after mild-alkali treatments, revealed that these lipids A share the common bisphosphorylated β-(1→6)-linked d-glucosamine disaccharide with hydroxydecanoic acid in an amide linkage. Short-chain FAs, hydroxydecanoic and dodecanoic acid, were found in a 2:1 ratio. The two lipid A structures differed by the relative amount of the hexa-acyl molecular species and phosphoethanolamine substitution of the phosphate groups. The two V. filiformis LPS batches induced variable interleukin-6 and TNF-α secretion by stimulated myelomonocytic THP-1 cells, without any difference in reactive oxygen species production or activation of caspase 3/7. Other different well-known highly purified LPS samples were characterized structurally and used as standards. The structural data obtained in this work explain the low inflammatory response observed for V. filiformis LPS and the previously demonstrated beneficial effects on the skin.
Project description:The raffinose family of oligosaccharides (RFOs) serve as transport carbohydrates in the phloem, storage compounds in sink tissues, and putative biological agents to combat both abiotic and biotic stress in several plant species. To investigate further the functional roles of this class of compounds in trees, two cDNAs encoding galactinol synthase (GolS, EC 2.4.1.123), which catalyses the first step in the biosynthesis of RFOs, were identified and cloned from hybrid poplar (Populus alba×grandidentata). Phylogenetic analyses of the Populus GolS isoforms with other known GolS proteins suggested a putative role for these enzymes during biotic or abiotic stress in hybrid poplar. The predicted protein sequences of both isoforms (Pa×gGolSI and Pa×gGolSII) showed characteristics of GolS proteins from other species, including a serine phosphorylation site and the ASAAP pentapeptide hydrophobic domain. Kinetic analyses of recombinant Pa×gGolSI and Pa×gGolSII resulted in K(m) values for UPD-galactose of 0.80 and 0.65 mM and V(max) values of 657.5 and 1245 nM min(-1), respectively. Pa×gGolSI inherently possessed a broader pH and temperature range when compared with Pa×gGolSII. Interestingly, spatial and temporal expression analyses revealed that Pa×gGolSII transcript levels varied seasonally, while Pa×gGolSI did not, implying temperature-regulated transcriptional control of this gene in addition to the observed thermosensitivity of the respective enzyme. This evidence suggested that Pa×gGolSI may be involved in basic metabolic activities such as storage, while Pa×gGolSII is probably involved in seasonal mobilization of carbohydrates.
Project description:AbstractChronic complications of traumatic brain injury represent one of the greatest financial burdens and sources of suffering in the society today. A substantial number of these patients suffer from posttraumatic headache (PTH), which is typically associated with tactile allodynia. Unfortunately, this phenomenon has been understudied, in large part because of the lack of well-characterized laboratory animal models. We have addressed this gap in the field by characterizing the tactile sensory profile of 2 nonpenetrating models of PTH. We show that multimodal traumatic brain injury, administered by a jet-flow overpressure chamber that delivers a severe compressive impulse accompanied by a variable shock front and acceleration-deceleration insult, produces long-term tactile hypersensitivity and widespread sensitization. These are phenotypes reminiscent of PTH in patients, in both cephalic and extracephalic regions. By contrast, closed head injury induces only transient cephalic tactile hypersensitivity, with no extracephalic consequences. Both models show a more severe phenotype with repetitive daily injury for 3 days, compared with either 1 or 3 successive injuries in a single day, providing new insight into patterns of injury that may place patients at a greater risk of developing PTH. After recovery from transient cephalic tactile hypersensitivity, mice subjected to closed head injury demonstrate persistent hypersensitivity to established migraine triggers, including calcitonin gene-related peptide and sodium nitroprusside, a nitric oxide donor. Our results offer the field new tools for studying PTH and preclinical support for a pathophysiologic role of calcitonin gene-related peptide in this condition.