杨树木质部特异性定位表达4CL1启动子的结构与表达特性

4-香豆素COA连接酶(4CL1)是木质素代谢途径中的一个关键酶,对该基因启动子的表达特性与调控元件进行了研究:首先,对毛白杨4CL1启动子进行了生物信息学分析,结果表明该启动子包括3个顺式作用元件,box P(CCTTCACCAACCCCC),box A(CCGTTC),box L(TCTCACCAACC),这3个顺式作用元件在已知的木质素代谢途径相关酶系如苯丙氨合成酶(PAI)和4CL中普遍存在;其次,运用PCR方法对该启动子进行了剪切,获得一个长393 bp的启动子片断,该启动子片断包括以上3个顺式作用元件;最后,将该启动子片段与GUS报告基因构建了植物表达载体并转化烟草,成功获得转基因再生苗,结果发现转基因烟草的茎木质部呈现GUS染色阳性.研究结果表明,一个393 bp长度的4CL1启动子片断足以介导外源基因在木质部特异性定位表达.     

波氏假丝酵母启动子的克隆及新霉素基因的表达

报道了波氏假丝酵母（Candida boidinii)启动子的克隆,将克隆的启动子与Neo^ 基因重组构建了含Neo^r基因的表达载体YepNP181,转化波氏假丝酵母,实现了Neo^r基因在波氏假丝酵母中的表达,使波氏假丝酵母转化子能在含G418的抗性培养基上生长从而建立了Neo^r基因－G418选择系统,为外源基因在波氏假丝酵母中表达创造了条件。     

丙烯直接环氧化Au/TiO2催化剂助剂对催化性能的影响

采用沉积沉淀法制备了一系列的Au／TiO2催化剂,分别考察了碱金属氯化物以及贵金属等助剂对Au／TiO2催化丙烯环氧化性能的影响。结果表明：催化剂中加入NaCl后其环氧化催化性能明显提高,含量为1．5％时环氧丙烷(PO)得率最高;而加入CsCl和贵金属Pt则有利于提高丙烯环氧化过程中氢气的利用效率,抑制了副产物水生成。     

Obtaining High Pest-resistant Tobacco Plants Carrying B.t. insecticidal Gene

To increase the expression level of CryIA(c) gene in transgenic plants, a plant expression vector pBinMoBc carrying the CryIA(c) gene under control of chimeric OM promoter and Ω factor was constructed. As a control, pBinoBc carrying the CryIA(c) gene with the CaMV 35S promoter was also constructed. The vectors were transferred into tobacco plants respectively via Agrobacterium-mediated transformation. ELISA assay showed that the expression level of the CryIA(c) gene in pBinMoBc transgenic tobacco plants was 2.44-times that in pBinoBc transgenic tobacco plants, and it could be up to 0.255% of total soluble proteins. Bioassay showed that pBinMoBc transgenic tobacco plants had more notable insecticidal effect than pBinoBc transgenic tobacco plants. The above results showed that the chimeric OM promoter was a stronger promoter than CaMV 35S promoter that was widely used in plant genetic engineering, and this is very useful in pest-resistant plant genetic engineering.     

融合表面抗原SA—28基因在Pichia pastoris酵母系统中的表达

将乙肝病毒表面抗原Ｓ－ｐｒｅＳ１融合基因ＳＡ－２８插入质粒载体ｐＡＯ８１５的ＥｃｏＲ Ｉ位点中,将其置于Ｐｉｃｈｉａ Ｐａｓｔｏｒｉｓ 酵母ＡＯＸ１启动子控制下,利用电转化技术,融合基因表达单元链同ＨＩＳ４基因被整合到受体菌ＳＭＤ１１６８基因组中。对得到的工程菌进行发酵和表达产物的研究表明：ＳＡ－２８基因在该系统中的表达受甲醇诱导调控;ＳＡ－２８融合基因的表达产物具有Ｓ和ＰｒｅＳ１的双重抗原性。用     

Construction of chimeric inducible promoters by elicitors of rice fungal blast pathogen and their expression in transgenic rice

The promoter fragments of wheatGstA1 and potatoGst1 have been amplified by PCR, cloned and fused respectively to the minimal promoter sequence of rice actin gene (Act1)) and its 5′ untranslated leader sequence together withGUS. The constructs with 2 chimeric promoters (WGA and PGA) have been transferred into rice in order to analyze their inducibility patterns in transgenic rice plants. The results show that: WGA and PGA are both inducible by elicitors ofPyricularia oryzae in transgenic rice cells; the intron I of riceAct1 gene is important for the heterogenic expression of monocot and dicot promoter elements in rice; and theAct1 minimal promoter and its 5′ untranslated leader sequence produced low level background expression in rice.     

Enhanced late blight resistance of transgenic potato expressing glucose oxidase under the control of pathogen-inducible promoter

To engineer crop disease resistance by utilizing natural defense mechanism that was expressed in the incompatible host-pathogen interactions is expected to result in a durable and broad-spectrum resistance. In order to prove this viewpoint, we amplified the coding region of the glucose oxidase (GO) gene from Aspergillus niger via PCR and fused it to the pathogen-inducible promoter, Prp1-1. The chimeric gene was cloned into a plant expression vector and conjugated into Agrobacterium. Twenty-three transgenic potato plants were obtained by Agrobacterium-mediated transformation. The integration of GO gene was confirmed by Southern hybridization and the GO gene expression was identified with KI-starch color reaction. Phytophthora infestans inoculation revealed that the expression of the chimeric transgene was induced by pathogen infection. Most of the transgenic plants exhibited various degrees of enhanced disease resistance. Four of them had lesion sizes reduced to less than half of the non-transgenic controls. One plant showed disease resistance of the hypersensitive response. These results testified the feasibility of our strategy of expressing GO transgene under the control of the disease-inducible promoter in engineering crop disease resistance.     

几种碱金属元素对硫酸催化剂低温活性的影响

研究了用冶金废液制备的低温硫酸催化剂中铯、铷、锂等碱金属元素的助催化作用和熔盐用量对催化剂低温活性的影响．结果表明,铯的低温助催化效果最好,其用量宜控制在n(Cs)／n(V)=0．3～0．6．当n(Cs)／n(V)=0．6时,410℃的SO2转化率达42．5％,比无铯催化剂的SO2转化率高18．5％．铷的加入会降低催化剂的低温活性,宜采取措施降低废液中的铷含量．在多种碱金属元素混合使用的情况下,锂元素有较好的助催化作用,其最佳用量为n(Li)／n(V)=0．4,410℃时SO2转化率达46％．活性组分含量对催化剂低温活性和高温活性影响较大,n(M)／n(v)宜小于4．5．     

卡介苗中具启动子活性片段克隆及分析

利用启动子探针型质粒ｐＫＫ２３２－８从卡介苗染色体ＤＡＮ的ＢａｍＨＩ酶切片段中克隆到４个具启动功能的ＤＮＡ片段,测定各重组子对氯霉素（Ｃｍ）的抗性,其中含３．３Ｋｂ外源片段的重组质粒ｐＢＣＧ２大肠杆菌转化子在ＬＭ培养基上对Ｃｍ抗性可达１７０×１０－６ｇ／ｍＬ,作了该片段的限制性酶切图谱．对ｐＢＣＧ２利用ＳａｌⅠ位点,亚克隆出４种部分重叠的具启动功能的ＤＮＡ片段,这４种重组质粒分别命名为ｐＢＣＧ２－１,ｐＢＣＧ２－２,ｐＢＣＧ２－６和ｐＢＣＧ２－８,并分析了其中插入片段的大小及其转化子对Ｃｍ的抗性．将ｐＢＣＧ２－２的ＳａｌⅠ外源片段插入到分枝杆菌启动子探针型穿梭质粒ｐＥＱ３,获得一个可在卡介苗中表达ｌａｃＺ基因的重组子ｐＥＢ２２．斑点杂交实验证明,具有启动功能的ＤＮＡ片段来源于卡介苗的染色体ＤＮＡ．结果表明克隆到一个对大肠杆菌和卡介苗均具启动子活性的ＤＮＡ片段     

低温快速化学镀Ni-P合金的研究

研究了促进剂对低温化学镀Ni-P合金镀液镀速的影响,选得促进剂B孤用量为30g.L^-1时,对低温化学镀镍速度有明显提高;测定了温度pH值择镀速和镀层含磷量和硬度的影响,试验结果表明：当pH值一定时,温底升高,则镀速加快,镀层磷含量增加,硬度增大,当温度一定时,则pH值上升,镀速加快,镀层含磷量减少,镀层硬度增大。