东北锦鸡儿属一新变种──多花极东锦鸡儿

东北锦鸡儿属一新变种──多花极东锦鸡儿谢航,赵毓棠,杨成禄,杨景隆（东北师范大学生物系长春１３００２４）（旺起林场吉林永吉１３２２２５）关键词多花极东锦鸡儿ＡＮＥＷＶＡＲＩＥＴＹＯＦＣＡＲＡＧＡＮＡＦＲＯＭＮ．Ｅ．ＣＨＩＮＡ￥ＸｉｅＨａｎｇ;Ｚｈａｏ...     

酶联免疫吸附技术(ELISA)对大豆根瘤菌的鉴定

本文用直接ELISA法检测大豆根瘤菌USDA 110和RTt 50的纯培养菌体和根瘤。确定了该试验的最佳工作条件:酶标结合物HRP—Ab 110和HRP—Ab50的工作稀释度分别为1:3200和1:800,抗体Ab 110和Ab 50的工作稀释度分别为1:3200和1:800,抗原USDA 110和RTt 50的最适工作浓度均为6×10~7细胞/ml。该法能够特异地检测和区别慢生型和快生型大豆根瘤菌。在这两种类型的大豆根瘤菌中,同种内的少数菌株存在交叉反应,通过吸收可以消除,从而使ELISA的检测达到菌株     

ABA与植物胁迫抗性

ABA是一种重要的植物激素,受到生物胁迫和非生物胁迫的调控,在植物对胁迫耐受性和抗性中发挥着重要作用。本文着重阐述了植物胁迫对ABA的生物合成和代谢的调控、ABA在调控气孔关闭和调控基因表达从而调控植物耐逆性方面的作用,以及植物胁迫信号转导途径间的联系和交叉。     

微乳体系中11β-羟基甲羟孕酮的C1,2生物脱氢

为改善过程传质,提高甾类药物中间体11β-羟基甲羟孕酮C1,2生物脱氢转化率,采用简单节杆菌Arthrobacter simplex UR016菌株在Tween-80/乙醇/食油/水构成的微乳体系中进行生物脱氢,并考察了微乳体系组成、转化温度、投料浓度对脱氢反应的影响。结果表明:以菌体培养液作为水相,食油作为油相构建微乳体系,食油最适加量为10g/L,表面活性剂Tween-80加量为4g/L;底物经醇溶后水析投料,乙醇最适加量为发酵液体积的7%(V/V);最适转化温度为33oC;当底物浓度为4g/L时,在构建的微乳体系中转化46h,脱氢转化率达88.6%,与水相转化工艺相比提高了66.2%。在该体系中疏水性11β-羟基甲羟孕酮底物得到了有效的增溶和扩散,生物脱氢转化率明显提高。     

Valuing urban green spaces in mitigating climate change: A city‐wide estimate of aboveground carbon stored in urban green spaces of China's Capital

Urban green spaces provide manifold environmental benefits and promote human well‐being. Unfortunately, these services are largely undervalued, and the potential of urban areas themselves to mitigate future climate change has received little attention. In this study, we quantified and mapped city‐wide aboveground carbon storage of urban green spaces in China's capital, Beijing, using field survey data of diameter at breast height (DBH) and tree height from 326 field survey plots, combined with satellite‐derived vegetation index at a fine resolution of 6 m. We estimated the total amount of carbon stored in the urban green spaces to be 956.3 Gg (1 Gg = 10⁹ g) in 2014. There existed great spatial heterogeneity in vegetation carbon density varying from 0 to 68.1 Mg C ha^‐1, with an average density of 7.8 Mg C ha^?1. As expected, carbon density tended to decrease with urban development intensity (UDI). Likely being affected by vegetation cover proportion and configuration of green space patches, large differences were presented between the 95th and 5th quantile carbon density for each UDI bin, showing great potential for carbon sequestration. However, the interquartile range of carbon density narrowed drastically when UDI reached 60%, signifying a threshold for greatly reduced carbon sequestration potentials for higher UDI. These findings suggested that urban green spaces have great potential to make contribution to mitigating against future climate change if we plan and design urban green spaces following the trajectory of high carbon density, but we should be aware that such potential will be very limited when the urban development reaches certain intensity threshold.     

TAK1 is an essential regulator of BMP signalling in cartilage

TGFβ activated kinase 1 (TAK1), a member of the MAPKKK family, controls diverse functions ranging from innate and adaptive immune system activation to vascular development and apoptosis. To analyse the in vivo function of TAK1 in cartilage, we generated mice with a conditional deletion of Tak1 driven by the collagen 2 promoter. Tak1^col2 mice displayed severe chondrodysplasia with runting, impaired formation of secondary centres of ossification, and joint abnormalities including elbow dislocation and tarsal fusion. This phenotype resembled that of bone morphogenetic protein receptor (BMPR)1 and Gdf5-deficient mice. BMPR signalling was markedly impaired in TAK1-deficient chondrocytes as evidenced by reduced expression of known BMP target genes as well as reduced phosphorylation of Smad1/5/8 and p38/Jnk/Erk MAP kinases. TAK1 mediates Smad1 phosphorylation at C-terminal serine residues. These findings provide the first in vivo evidence in a mammalian system that TAK1 is required for BMP signalling and functions as an upstream activating kinase for Smad1/5/8 in addition to its known role in regulating MAP kinase pathways. Our experiments reveal an essential role for TAK1 in the morphogenesis, growth, and maintenance of cartilage.     

克鲁维酵母Y-85菊粉酶的纯化和性质

克鲁维酵母(Kluyveromyces sp.)Y-85产生的胞内菊粉酶(endocellular inulinase)和胞外菊粉酶(exocellular inulinase)粗酶液分别经PEG6000-磷酸盐缓冲液双水相抽提得部分纯化酶液。前者进一步用硫酸铵分级沉淀、Protein-PAK DEAE离子交换、Protein-PAK200SW凝胶过滤后得到两个菊粉酶组分EⅠ和EⅡ;后者采用DEAE-Sephacel离子交换、Sephadex G150凝胶过滤后得到菊粉酶Eexo。经Waters 650E蛋白纯化系统鉴定,三者均呈单一的对称峰;EⅠ和EⅡ达聚丙烯酰胺盘状凝胶电泳纯。EⅠ、EⅡ和Eexo的分子量分别为42kD、65kD和57kD;三者均为糖蛋白,多糖含量分别为30％、35％和25％;I/S(Inulinaseactivity/Sucrase activity)比值分别为0.086、0.078和0.072;三者均属外切菊粉酶。EⅠ、EⅡ和Eexo酶反应最适pH分别为4.6、4.5和4.6,最适温度分别为52℃、52℃和55℃;Ag^+、Hg^(2+)和PCMB对酶活性有强烈的抑制作用;三者水解菊芋粉糖液的产物均为果糖(86.5％)和葡萄糖(13.5％)。     

人红细胞生成素单克隆抗体的制备、鉴定及应用研究

用rhEPo作为抗原,免疫BALB／c小鼠,取其脾细胞与x63Ag8．653小鼠骨髓瘤细胞融合,再碱性PAGE方法进一步分离并纯化的rhEpo,包被Pvc板,对杂交瘤用ELlSA方法进行筛选,获得两株稳定分泌抗hEPO单抗的杂交瘤细胞株。经鉴定分别属于IgG1、IgG2b,轻链均为k链,Kd分别为5．53×10^-10mol／L和1．34×1O^-10mol／L．用western blot方法证明两者对hEPO具有高度韵专一性．能特异地识别rhEPO和尿源hEPO。所制备单抗可作为亲和层析的配体,用于再生障碍性贫血病人尿中EPO及哺乳类工程细胞所表达的hEPO的分离、纯化,并可用于hEPO的定量检测．     

植物小RNAs的研究进展

小RNAs(长度小于40 nt)是nc-RNAs重要的一部分,现在植物中已发现了多种小RNAs,如小干扰RNAs(siRNAs)、微小RNAs(miRNAs)、反式作用的小干扰RNAs、天然反义转录小干扰RNAs、异染色质小干扰RNAs、长小片段小干扰RNAs、天然反义转录的微小RNAs及其一些未命名的小RNAs.成熟的小RNAs聚集相关的蛋白质因子,可以抑制转录,导致转录水平的基因沉默(TGS);或介导目标mRNA的剪切,抑制翻译,导致转录后水平基因沉默(PTGS).就这些植物小RNAs产生及其作用的研究进展作一概述