CO2浓度增加和施氮对栓皮栎幼苗生理生态特征的影响

通过人为控制CO₂浓度(700、400 μmol·mol^-1)和氮素水平(120 kg N·hm^-2),研究了CO₂浓度增加和氮沉降及其交互作用对北界(辽宁庄河)栓皮栎幼苗生理生态特征的影响.结果表明: CO₂浓度升高使栓皮栎幼苗叶片的形态、光合色素含量和氮含量有减小的趋势,暗呼吸速率较对照降低63.3%,可溶性糖增加2.6%.氮沉降对栓皮栎叶片的形态和光合色素含量有明显的促进作用,叶N含量增加而K含量降低,N/K值增加26.7%.CO₂和N交互作用对幼苗叶形态和光合作用有明显的促进作用,叶片最大净光合速率和光饱和点分别是对照的1.4倍和2.6倍,暗呼吸速率和光补偿点分别降低65.9%和50.0%.CO₂浓度升高和N沉降均对栓皮栎幼苗生长有一定的促进作用,可能导致栓皮栎分布界线北移.     

钙库调控的钙通道Orai1体外研究方法的建立

目的:建立钙通道Orai1的体外研究方法。方法:利用脂质体重组技术,将体外纯化的Orai1蛋白重组到脂质体膜上,利用蔗糖密度梯度离心来检测其重组效率及Orai1蛋白在脂质体膜上的结构,并利用钙染料Fura-2检测脂质体内钙离子的释放。结果:成功制备了脂质体及体外纯化了GST-Orai1融合蛋白,蔗糖密度梯度离心结果证明GST-Orai1蛋白成功重组到脂质体上,以及Orai1蛋白以多聚体的形式定位在脂质体膜上。钙离子释放实验证明脂质体内钙离子包装完好,可用于后续Orai1钙通道的功能研究。结论:利用脂质体重组技术建立了一种新的Orai1的研究方法,能够更直接有效地研究其功能及其活化机制。     

Anatomy of a New Species of Scolecopteris (Marattiales) from Early Stage of Early Permian in China

Scolecopteris Zenker, a kind of anatomically-preserved fertile foliage of Late Paleozoic Marattiales, has been well studied in Euramerican Flora. It is composed of 28 species which can be divided into four forms (groups) mainly based on modified or umodified pinnules, the variation of the outer facing sporangial walls, and with or without a prominent central parenchyma area. In contrast, Scolecopteris Zenker in Cathaysian Flora has been poorly studied so far, and only one species S. sinensis Zhao, was reported in 1991 which was considered as a member of Minor Group. The paper reports a second species of Scolecopteris, i.e.S, shanxiensis sp. nov., which differs from the above four groups in that its outer facing wall of the sporangia is thick at the base and top (2 ~ 3 layers of cells), and a little thinner ( 1~2 layers of cells) at the midlevel of the synangia. So a new group, Shanxiensis group, is set for the new species. The other characteristics of Shanxiensis group is comparable with Minor group. The new species comes from the coal balls in Coal Seam No. 7 in the upper part of Taiyuan Formation (early Early Permian) from Taiyuan, Shanxi, China. The identification of Scolecopteris shanxiensis sp. nov. :The fertile pinnule probably peeopterids, 5.5 ~ 6.0 mm in length and 2.0 ~ 2.2 mm in width. The lateral extensions of the lamina of the pinnule bend abaxially and above the synangia. The synangia arrange along the sides of the midrib of the pinnnle and there are about 10 synangia in each row. The synangium is elliptical in longitudinal section and radial in cross section, 0.7 ~ 0.8 mm in height and 0.6 ~ 0.7 mm in diameter. Each synangium has 5-7 (mostly 6) fusiform sporangia fused at the base and attached to the top of the synangial pedicel. The outer facing wall of the sporangia consists of 2~3 layers of cells at the base and becomes thinner at the midlevel (1~2 layers of cells), and at the top of the synangia the wall become thicker again. The cells of the outer facing wall of the sporangia are elongate in the longitudinal sections. The lateral and inner facing walls of the sporangia are one cell thick. The synangial pedicel is small. Spores in situ are small, generally 11~14 µm in diameter, spherical or rounded-triangular, trilete and smooth-walled.     

13C脉冲标记法：不同生育期水稻光合碳在植物-土壤系统中的分配

定量生育期内植物光合碳在植物组织-土壤的分配规律,对于理解全球碳循环有着重要意义。采用~(13)C-CO_2脉冲标记结合室内培养,通过元素分析仪-稳定同位素联用(Flash HT-IRMS)分析植物各部分及土壤δ~(13)C值,比较了不同生育期下水稻光合碳在不同组织间的分配规律,并量化了水稻光合碳向土壤碳库的转移。结果表明:(1)水稻地上部和根系干物质量随水稻生育期的增加而呈现递增趋势,不同的生育期表现为:分蘖期拔节期抽穗期扬花期成熟期。而整个生育期的根冠比为0.2—0.4,分蘖期的根冠比最高,随着水稻生育期的增加而递减,到抽穗期以后根冠比稳定在0.2左右。(2)脉冲标记6h后,水稻地上部和地下部(根系)的δ~(13)C值在-25.52‰—-28.33‰,不同器官的δ~(13)C值存在明显分馏效应,且趋势基本一致,即茎杆(籽粒)叶片(根系);这种由于水稻生育期特性导致的各器官碳同位素分馏的现象,可用于指示不同生育期下水稻光合碳的分配和去向。(3)不同生育期~(13)C-光合碳在植物-土壤系统的分配规律不同,生长前期光合碳向根系及土壤中分配的比例高,具有较强的碳汇能力,而随生育期光合碳在根系及土壤中的分配比例呈下降趋势,但积累量不断增加。(4)不同生育期~(13)C光合碳在水稻-土壤系统中的分配比例差异明显。水稻分蘖期有近30%光合碳用于根系建成并部分通过根系分泌物进入土壤有机碳库(10%),而到成熟期则向籽粒中分配较多,而且光合碳在土壤中的分配比例也随生育期呈下降趋势。研究结果对稻田土壤有机碳循环过程和调控机制的揭示具有重要的理论意义。     

埃博拉病毒来源miRNA的研究综述

近年来,随着对microRNA（miRNA）的广泛研究,人们发现,不仅有细胞结构的生物具有产生miRNA的能力,无细胞结构的病毒同样具有产生miRNA从而影响自身复制及调控宿主基因表达和信号通路的能力。埃博拉病毒（Ebola virus,EBOV）已经多次导致一定规模的流行,病毒的高致死率和复杂的致病机制引起了人们的高度重视,多项研究指出EBOV具有产生miRNA的能力,且在其感染过程中发挥一定的作用。本文对埃博拉病毒来源miRNA的预测、证实及检测相关研究进行综述,以期为全面了解EBOV来源的miRNA提供参考。     

中国鄂温克、鄂伦春、达斡尔族永生细胞系的建立与保存

本采用ＥＢＶ（Ｅｐｓｔｅｉｎ－Ｂａｒｒ Ｖｉｒｕｓ）上清液转化Ｂ淋巴细胞,并加入环胞霉素Ａ（Ｃｙｃｌｏｓｐｏｒｉｎｅ Ａ）抑制Ｔ淋巴细胞,成功地对中国东北地区鄂温克族、鄂伦春族及达斡尔族的部分个体建立了永生细胞系,其中鄂温克族４９株,鄂伦春族４０株,达斡尔族５１例,总计１４０株。永久保存我国特有民族的基因组,为分析其遗传学差异奠定了基础。     

竹叶柴胡地上部分的化学成分

竹叶柴胡(Bupleurum marginatumWall.ex DC.)为伞形科(Apiaceae)柴胡属(BupleurumL.)植物,主要分布于四川北部、陕西南部、湖北西部及云南、贵州等省区,全株均可入药,为目前市场上药材柴胡的三大主要来源之一。柴胡具解表和里、疏肝解郁、提升中气之功效,在中药学中具有重要地位,在中国也已有2000多年的应用历史。目前,有关北柴胡(B.chinenseDC.)及南柴胡(B.scorzonerifoliumWilld.)的相关研究较多,而对在西南地区广泛使用的竹叶柴胡的研究却甚少。另外,对柴胡的相关研究多集中于根及根茎,有关柴胡茎叶化学成分和药理作用的研究较少。…     

Expression and Sequence Analysis of a cDNA Relative to Orchid Ovule Development

The Phalaenopsis sp. cv. SM 9108 flower provides a good system to isolate ovule-specific genes. A cDNA library at mature ovule stage has been constructed. A differential screening approach was used to identify cDNAs representing genes which are expressed in a stage-specific manner during ovule development. The authors have demonstrated that the expression of a cDNA (0138) was regulated stage-specifically and tis-sue-specifically using, Northern blot, and also have analyzed the full sequence of this cDNA. Its further functional characterization in ovule development will be facilitated.     

基于邻接矩阵分解的肿瘤亚型特征提取方法

基于肿瘤基因表达谱的肿瘤分类是生物信息学的一个重要研究内容。传统的肿瘤信息特征提取方法大多基于信息基因选择方法,但是在筛选基因时,不可避免的会造成分类信息的流失。提出了一种基于邻接矩阵分解的肿瘤亚型特征提取方法,首先对肿瘤基因表达谱数据构造高斯权邻接矩阵,接着对邻接矩阵进行奇异值分解,最后将分解得到的正交矩阵特征行向量作为分类特征输入支持向量机进行分类识别。采用留一法对白血病两个亚型的基因表达谱数据集进行实验,实验结果证明了该方法的可行性和有效性。