Vegetation and soil properties in restored wetlands near Lake Taihu,China

Riparian wetlands are important components of the lake ecosystem, and they play essential roles in maintaining system health. Remediation of degraded lakeshore wetlands is an essential component of lake restoration. A study was conducted to investigate the restoration of lakeshore wetlands, which were converted to rice fields and then abandoned for 2, 5, 10 and 15 years, near Lake Taihu. Soil samples (0–20 cm and 20–40 cm) were taken and plant species were investigated. The carbon content in the soil had increased significantly, rising from 0.71% to 1.85% between 2 and 15 years. Organic matter accumulation improved soil texture, and water stable aggregate content (>0.25 mm) and soil porosity increased. Total nitrogen in the soil increased from 0.06% to 0.13%, and total Kjeldahl nitrogen increased from 124.4 mg kg⁻¹ to 351.5 mg kg⁻¹. Total phosphorus in the soil increased from 0.045% to 0.071%, and the Olsen-P value increased from 5.13 mg kg⁻¹ to 16.0 mg kg⁻¹. Results showed that phosphorous did not increase as much as nitrogen. In the vegetation restoration process, plant species composition moved towards a natural wetland community, and spatial heterogeneity and landscape diversity increased. The richness of plant biodiversity increased rapidly in the first 2 years, then more slowly in later restoration stages. The wetlands recovery process may be complicated by interactions of biota and soil and hydrological conditions.     

Metabolic changes of the reduction of manganese intake in the hepatic encephalopathy rat: NMR- and MS-based metabolomics study

BioMetals - To investigate the metabolic changes in type C hepatic encephalopathy (CHE) rats after reducing manganese (Mn) intake. A total of 80 Sprague–Dawley rats were divided into control...     

牦牛MC1R基因的克隆测序及其分析研究

以麦洼牦牛、斯布牦牛、天祝牦牛和九龙牦牛为研究对象,对黑色素皮质素受体1(Melanocortin receptor I,MCIR)基因编码区进行了克隆测序及分析.结果表明,牦牛的MC1R基因编码区全长954 bp,编码317个氨基酸:4个牦牛品种间及与普通牛间在MC1R基因的编码区内共有13个碱基差异,无碱基的插入和缺失现象,编码蛋白共有9个氨基酸差异.MC1R蛋白为亲水性蛋白,无信号肽,有糖基化位点和7个跨膜区.系统进化分析显示,麦洼牦牛与斯布牦牛的MC1R基因相似性最近.本研究结果时今后开展MC1R基因与牦牛毛色性状的相关性分析以及牦牛的毛色遗传机理、基因定位、基因表达调控等研究具有重要的意义.     

Inhibition of GPR40 protects MIN6 β cells from palmitate-induced ER stress and apoptosis

Chronic exposure to elevated concentration of free fatty acids (FFA) has been verified to induce endoplasmic reticulum (ER) stress, which leads to pancreatic β-cell apoptosis. As one of the medium and long chain FFA receptors, GPR40 is highly expressed in pancreatic β cells, mediates both acute and chronic effects of FFA on β-cell function, but the role of GPR40 in FFA-induced β-cell apoptosis remains unclear. In this study, we investigated the possible effects of GPR40 in palmitate-induced MIN6 β-cell apoptosis, and found that DC260126, a novel small molecular antagonist of GPR40, could protect MIN6 β cells from palmitate-induced ER stress and apoptosis. Similar results were observed in GPR40-deficient MIN6 cells, indicating that palmitate-induced β-cell apoptosis is at least partially dependent on ER stress pathway via GRP40.     

YbxF and YlxQ are bacterial homologs of L7Ae and bind K-turns but not K-loops

The archaeal protein L7Ae and eukaryotic homologs such as L30e and 15.5kD comprise the best characterized family of K-turn-binding proteins. K-turns are an RNA motif comprised of a bulge flanked by canonical and noncanonical helices. They are widespread in cellular RNAs, including bacterial gene-regulatory RNAs such as the c-di-GMP-II, lysine, and SAM-I riboswitches, and the T-box. The existence in bacteria of K-turn-binding proteins of the L7Ae family has not been proven, although two hypothetical proteins, YbxF and YlxQ, have been proposed to be L7Ae homologs based on sequence conservation. Using purified, recombinant proteins, we show that Bacillus subtilis YbxF and YlxQ bind K-turns (K(d) ~270 nM and ~2300 nM, respectively). Crystallographic structure determination demonstrates that both YbxF and YlxQ adopt the same overall fold as L7Ae. Unlike the latter, neither bacterial protein recognizes K-loops, a structural motif that lacks the canonical helix of the K-turn. This property is shared between the bacterial and eukaryal family members. Comparison of our structure of YbxF in complex with the K-turn of the SAM-I riboswitch and previously determined structures of archaeal and eukaryal homologs bound to RNA indicates that L7Ae approaches the K-turn at a unique angle, which results in a considerably larger RNA-protein interface dominated by interactions with the noncanonical helix of the K-turn. Thus, the inability of the bacterial and eukaryal L7Ae homologs to bind K-loops probably results from their reliance on interactions with the canonical helix. The biological functions of YbxF and YlxQ remain to be determined.     

Decline in topsoil microbial quotient, fungal abundance and C utilization efficiency of rice paddies under heavy metal pollution across South China

Agricultural soils have been increasingly subject to heavy metal pollution worldwide. However, the impacts on soil microbial community structure and activity of field soils have been not yet well characterized. Topsoil samples were collected from heavy metal polluted (PS) and their background (BGS) fields of rice paddies in four sites across South China in 2009. Changes with metal pollution relative to the BGS in the size and community structure of soil microorganisms were examined with multiple microbiological assays of biomass carbon (MBC) and nitrogen (MBN) measurement, plate counting of culturable colonies and phospholipids fatty acids (PLFAs) analysis along with denaturing gradient gel electrophoresis (DGGE) profile of 16S rRNA and 18S rRNA gene and real-time PCR assay. In addition, a 7-day lab incubation under constantly 25°C was conducted to further track the changes in metabolic activity. While the decrease under metal pollution in MBC and MBN, as well as in culturable population size, total PLFA contents and DGGE band numbers of bacteria were not significantly and consistently seen, a significant reduction was indeed observed under metal pollution in microbial quotient, in culturable fungal population size and in ratio of fungal to bacterial PLFAs consistently across the sites by an extent ranging from 6% to 74%. Moreover, a consistently significant increase in metabolic quotient was observed by up to 68% under pollution across the sites. These observations supported a shift of microbial community with decline in its abundance, decrease in fungal proportion and thus in C utilization efficiency under pollution in the soils. In addition, ratios of microbial quotient, of fungal to bacterial and qCO(2) are proved better indicative of heavy metal impacts on microbial community structure and activity. The potential effects of these changes on C cycling and CO(2) production in the polluted rice paddies deserve further field studies.     

Modulating the root elongation by phosphate/nitrogen starvation in an OsGLU3 dependant way in rice

Previously, we showed that OsGLU3, a β-1,4-endoglucanase, can affect the cellulose synthesis for root elongation in rice. And the phosphate starvation induced root elongation in rice depends on the function of OsGLU3. Here, we further showed that OsGLU3 is also dispensable for nitrogen starvation induced root elongation in rice.     

Effects of interaction with sulphur compounds and free volume in imidazolium-based ionic liquid on desulphurisation: a molecular dynamics study

Interaction energy with sulphur compounds and free volume in imidazolium-based ionic liquid were calculated by molecular dynamics (MD) simulations to examine their effects on desulphurisation. From microstructure analysis and energy contribution calculation, it is found that an increasing fractional free volume in ionic liquid and an enhancement of interaction with solute by tuning the structure of ionic liquid or oxidising sulphur compounds are favourable for desulphurisation, which allows more efficient packing of sulphur compounds in ionic liquids and more easily extraction of sulphur compounds from fuel. The MD results are in good agreement with experimental desulphurisation performance.