Different leaf carbon,nitrogen, and phosphorus stoichiometry and carbon and nitrogen isotopes among peatland plants in northeastern China

Plant and Soil - Plant carbon (C), nitrogen (N), phosphorus (P) levels and their stoichiometry and N uptake strategies are important aspects influencing vegetation composition and C dynamics in...     

microRNA-206 overexpression inhibits epithelial-mesenchymal transition and glomerulosclerosis in rats with chronic kidney disease by inhibiting JAK/STAT signaling pathway

Chronic kidney disease (CKD) is a traumatic disease with significant psychic consequences to the patient's overall physical condition. microRNA-206 (miR-206) has been reported to play an essential role in the development of various diseases. The purpose of the present study is to investigate the effect of miR-206 through the JAK/STAT signaling pathway on epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells and glomerulosclerosis in rats with CKD. The targeting relationship between miR-206 and ANXA1 was verified. To explore the role of miR-206 in CKD, the model of CKD rats was established to detect glomerular sclerosis index (GSI), contents of interleukin-6 (IL-6) and transforming growth factor-beta1 (TGF-β1), and expression of type IV collagen. Moreover, to further determine the roles of both miR-206 and the JAK/STAT signaling pathway in CKD, the gain- and loss-of function approaches were performed with the expression of ANXA1, α-SMA, E-cadherin, vimentin, N-cadherin, and the JAK/STAT signaling pathway-related genes detected. miR-206 negatively targeted ANXA1. Overexpressed miR-206 inhibited the degeneration and interstitial fibrosis of renal tubular epithelial cells, decreased GSI of rats, and the expression of type IV collagen, TGF-β1 and IL-6. Overexpressed miR-206 inhibited the degeneration of renal tubular epithelial cells, the expression of ANXA1, α-SMA, TGF-β1, p-STAT3, STAT3, p-STAT1, STAT1, p-JAK2, and JAK2, while promoted the expression of E-cadherin. Taken together the results, miR-206 inhibits EMT of renal tubular epithelial cells and glomerulosclerosis by inactivating the JAK/STAT signaling pathway via ANXA1 in CKD.     

以提高教学质量为目标开展“普通植物病理学”课程考试改革

为进一步提高教学质量,培养高素质人才,高校应加大课程考试改革的力度。本文针对“普通植物病理学”课程考试中存在的主要问题,结合课程教学的特点,坚持理论联系实际,积极探索了贯穿于课程教学全过程,能够促进学生提高能力和素质的多元化的综合考核模式。     

空心莲子草野螟各虫态的形态学观察

采用室内观察的方法,使用万能视频成像装置( LY-WN-HP SUPERCCD),对空心莲草野螟Herpetogramma fuscescens（Warren,1892）各虫态的形态学特征进行了系统观察.结果发现:成虫体小型,灰褐色.卵椭圆形,初产时乳白色,块状,外被腊质层.孵化前,部分卵壳分离为白色蜡质外层和棕黄色内...     

Defluviitalea phaphyphila sp. nov., a Novel Thermophilic Bacterium That Degrades Brown Algae

Brown algae are one of the largest groups of oceanic primary producers for CO₂ removal and carbon sinks for coastal regions. However, the mechanism for brown alga assimilation remains largely unknown in thermophilic microorganisms. In this work, a thermophilic alginolytic community was enriched from coastal sediment, from which an obligate anaerobic and thermophilic bacterial strain, designated Alg1, was isolated. Alg1 shared a 16S rRNA gene identity of 94.6% with Defluviitalea saccharophila LIND6LT2^T. Phenotypic, chemotaxonomic, and phylogenetic studies suggested strain Alg1 represented a novel species of the genus Defluviitalea, for which the name Defluviitalea phaphyphila sp. nov. is proposed. Alg1 exhibited an intriguing ability to convert carbohydrates of brown algae, including alginate, laminarin, and mannitol, to ethanol and acetic acid. Three gene clusters participating in this process were predicted to be in the genome, and candidate enzymes were successfully expressed, purified, and characterized. Six alginate lyases were demonstrated to synergistically deconstruct alginate into unsaturated monosaccharide, followed by one uronic acid reductase and two 2-keto-3-deoxy-d-gluconate (KDG) kinases to produce pyruvate. A nonclassical mannitol 1-phosphate dehydrogenase, catalyzing d-mannitol 1-phosphate to fructose 1-phosphate in the presence of NAD⁺, and one laminarase also were disclosed. This work revealed that a thermophilic brown alga-decomposing system containing numerous novel thermophilic alginate lyases and a unique mannitol 1-phosphate dehydrogenase was adopted by the natural ethanologenic strain Alg1 during the process of evolution in hostile habitats.     

中国北方上中新统的早期玛姆象属(Mammut)及其在玛姆象科(Mammutidae)分化和演化中的意义

玛姆象属是长鼻类玛姆象科这一重要类群的最终成员.虽然这一属在上新世的欧亚大陆和更新世的北美大陆广泛分布,它早期的进化历史却鲜为人知.报道了中国北方上中新统发现的斜脊玛姆象(相似种)(Mammut cf.M.obliquelophus)的新材料,包括一个几乎完整的幼年头骨,这些材料显示了玛姆象科的许多原始特征,因此很好地解释了玛姆象属形态特征的形成过程.斜脊玛姆象(相似种)具有强烈向两侧扩展的枕部,在门齿窝的基部具有收缩,这些特征与莫罗托始轭齿象(Eozygodon morotoensis)和广河豕脊齿象(Choerolophodon guangheensis)均具有相似性,后两者分别为玛姆象科与豕脊齿象科的早期代表.因此,玛姆象科与豕脊齿象科(Choerolophodontidae)具有近的亲缘关系,二者同位于象形类(Elephantimorpha)系统发育中的基部.支序分析支持了这一结论.     

植物钙结合蛋白与钙离子结合鉴定技术的研究进展

Ca2＋在植物生长发育和环境适应过程中发挥着中心调控作用,钙信号是植物生长发育和逆境响应的主要调控因子,钙结合蛋白是植物钙信号传导途径的最重要组分之一,然而植物钙结合蛋白在体内和体外与Ca2＋结合的技术体系还有待完善和发展。为了系统总结植物钙结合蛋白的鉴定方法与技术,本文从定性结合、定量结合和结合方式等角度,综述了植物钙结合蛋白在体内和体外条件下与Ca2＋结合的原理、方法、特点和应用前景,详细阐述了近年来的主要检测方法,并对其今后的发展趋势作了展望。本文将为植物钙结合蛋白的分离、功能鉴定和作用机制的研究提供技术支撑。