Transformation of the salt-tolerant gene of<Emphasis Type="Italic">Avicennia marina</Emphasis> into tobacco plants and cultivation of salt-tolerant lines

Salt-tolerant gene, CSRG1, which was isolated from a kind of salt-tolerant mangroves, Avicennia marina, constructed the transgenic plasmid, pGAM189/CSRG1. CSRG1, GUS, Kmr and Hyg^r could be transferred into tobacco genome by the ameliorated leaf discs method of agro-bacterium-mediate transformation. Thirteen stable resistant lines were obtained when fifty transgenic explants were selected through 50 mg/L hygromycin and 150 mg/L kanamycin. Assessments of PCR amplification, Southern blot analysis and GUS histochemical staining showed that CSRG1 has been integrated into the genome of the eleven transgenic lines (frequency of transformation was 22%). Northern bolt analysis revealed that CSRG1 had expressed in transgenic lines. The assessments of salt-tolerant ability and photosyn-thetic rates indicated that the survival rate of the transgenic lines is 80%—90% and the transgenic lines could increase by 30%—40% in plant height, even when they were cultivated in MS medium containing 2% NaCl and the total seawater (salinity 24). It is supposed that the special physiologic metabolic pathway formed by the products of CSRG1 can really endow the tobacco plants with the high salt-tolerant ability, not only to Na^ stress, but also to the comprehensive stress of various ions.     

Mathematical modeling of salt-gradient ion-exchange simulated moving bed chromatography for protein separations

The salt-gradient operation mode used in ion-exchange simulated moving bed chromatography (SMBC) can improve the efficiency of protein separations. A detailed model that takes into account any kind of adsorption/ion-exchange equilibrium, salt gradient, size exclusion, mass transfer resistance, and port periodic switching mechanism, was developed to simulate the complex dynamics. The model predictions were verified by the experimental data on upward and downward gradients for protein separations reported in the literature. All design and operating parameters (number, configuration, length and diameter of columns, particle size, switching period, flow rates of feed, raffinate, desorbent and extract, protein concentrations in feed, different salt concentrations in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale-up of salt-gradient ion-exchange SMBC for protein separations.     

盐雾胁迫下杜英等树种生理特性的变化

以饱和NaCl溶液模拟盐雾胁迫对杜英等11个树种在盆栽条件下测定叶片叶绿素含量、SOD活性、MDA含量和游离脯氨酸含量4项生理指标动态变化状况。结果表明,不同树种耐盐雾性因胁迫时间长短存在明显差异,其中盐雾胁迫1d时,11个树种中耐盐雾性由强至弱排序依次为木荷、杜英、晚松、南酸枣、杨梅、马尾松、香樟、二次结实板栗、湿地松、玉环长柿和枫香;当盐雾胁迫3d时,11个参试树种中晚松、杨梅、耐盐雾性较强,枫香最弱;而当盐雾胁迫维持时间达6d时,则11个参试树种中木荷、杨梅耐盐雾性最强,枫香依然最弱。     

Eisenia fetida中蚯蚓纤溶酶P-Ⅲ组分序列克隆与分析

从Eisenia fetida中提取总RNA,利用P-Ⅲ组分序列两端的保守性设计引物,通过RT-PCR获得P-Ⅲ组分基因,并构建该组分质粒(pUC18)文库,经PCR筛选后进行序列测定及分析。在原已获得的Efp-Ⅲ-1和Efp-Ⅲ-3的基础上,利用中间引物从文库中筛选到Efp-Ⅲ-2基因。序列分析表明,该基因编码序列为720bp,编码239个氨基酸,与GenBank报道的Efp-Ⅲ-2五条序列整体相似性高达99.02%。通过序列比对,发现Efp-Ⅲ-1、2和3具有完全相同的结构域,差异位点零星分布在序列中间本文首次由一个实验室获得P-Ⅲ组分的三个亚组序列,序列比对分析证明它们是蚯蚓体内P-Ⅲ组分基因多态性的表现。     

融盐包裹法合成球形正极材料LiNi_(0.7)Co_(0.2)Al_(0.1)O_2(英文)

以球形Ni(OH)2为核心原料,Al(NO3)3.9H2O、Co(NO3)2.6H2O和LiNO3为包裹原料,采用融盐包裹法在空气中煅烧合成了单相固溶体LiNi0.7Co0.2Al0.1O2。用XRD研究了合成产物的物相和结构,用SEM研究了合成产物的形貌,用电池性能测试仪研究了合成产物的电化学性能。实验结果表明,合成产物具有α-NaFeO2型层状有序结构、球状形貌和良好的电化学性能。     

固溶处理对7A55铝合金断裂韧性的影响

采用金相组织观察、拉伸实验、Kahn撕裂试验、扫描电镜、透射电镜等方法研究固溶处理对7A55铝合金断裂韧性的影响。研究结果表明:固溶温度对7A55铝合金断裂韧性影响显著,7A55铝合金在450～490℃时固溶,随着温度上升,可溶性粒子减少,断裂韧性增加,到480℃时断裂韧性达到最大值;当温度超过480℃时,由于晶粒的长大,断裂韧性又开始下降;7A55铝合金有很大的淬火敏感性,当以慢速淬火时,晶界非共格析出物尺寸粗大,对断裂韧性不利。     

水稻16kDa醇溶蛋白启动子克隆及载体构建

水稻种子16 kDa醇溶蛋白是水稻种子成熟过程中,由16 kDa基因编码,16 kDa醇溶蛋白启动子调控,在胚乳中特异表达的蛋白质.以水稻基因组DNA为模板,通过PCR扩增技术得到16 kDa启动子片段,序列分析结果表明:获得的启动子片段的大小为931 bp,与已报道的该启动子序列相比较,其核苷酸序列同源性为99.9%.该启动子区域含有TATA-box,CAAT-box,GCN4基序,Prolamin-box等胚乳特异表达启动子所必需的正调控元件.利用该启动子构建了植物种子特异表达载体pC16 kDP.     

盐分胁迫对绿豆幼苗若干生理生化指标的影响

实验采用水培的绿豆幼苗,模拟水分的积盐状况,用不同浓度的NaCl溶液作为渗透胁迫剂,分别用2%,4%,6%NaCl溶液对绿豆幼苗进行处理,观察其生长状况,测定其平均植株高度,脯氨酸含量。结果显示,随着盐分浓度的升高,绿豆幼苗伤害加重,生长状况不断恶化,植株平均株高降低,叶片及根中的脯氨酸含量均呈递增状况。     

一株耐盐芽孢杆菌的分离与鉴定

从校园草坪土壤中分离得到一株能够在20%NaCl的高盐条件下生长的耐盐细菌,经过形态观察、生理特征分析及16SrDNA序列分析,鉴定为一株芽孢杆菌(Bacillussp.),并在GenBank中完成该菌株16SrDNA序列的注册,登录号为EU167738.     

硅对赤泥分离过程影响的模拟试验

通过向拜耳联合法溶出矿浆中添加硅酸钠,研究硅含量对赤泥沉降性能的影响。实验研究表明:硅含量过高对溶出矿浆的沉降性能有明显的影响,添加适量的钙离子可以改善由于溶出矿浆中硅含量过高而引起的赤泥沉降性能下降。