转基因白桦中GUS基因表达的定量分析

以转基因白桦（Betula platyphylla）为材料,采用单酶切结合Southern杂交的方法揭示不同转基因植株中GUS基因的整合拷贝数为1—4个。采用组织化学染色法定性分析不同整合方式转基因白桦植株中GUS基因的表达。结果表明,11个转基因植株中有2株出现了GUS基因沉默,其余植株均有不同水平的GUS表达。在此基础上应用分光光度法定量分析不同拷贝数的GUS转基因白桦中β-葡萄糖醛酸酶活性。结果表明,在11个转基因尢性系中除2个株系的GUS基因沉默外,其它9个转基因植株中GUS酶活力差异明显,但这种差异与GUS基因的拷贝数没有必然联系。     

Molecular Dissection of Bombyx mori Nucleopolyhedrovirus orf8 Gene

Viruses including baculoviruses are obligatory parasites, as their genomes do not encode all the proteins required for replication. Therefore, viruses have evolved to exploit the behavior and the physiology of their hosts and often eoevolved with their hosts over millions of years. Recent comparative analyses of complete genome sequences of baculoviruses revealed the patterns of gene acquisitions and losses that have occurred during baculovirus evolution. In addition, knowledge of virus genes has also provided understanding of the mechanism of baculovirus infection including replication, species-specific virulence and host range. The Bm8 gene of Bombyx mori nucleopolyhedrovirus (NPV) and its homologues are found only in group I NPV genomes. The Autographa californica NPV Acl6 gene is a homologue of Bm8 and, encodes a viral structural protein. It has been shown that Bm8/Ac 16 interacts with baculoviral and cellular proteins. Bm8/Ac 16 interacts with baculoviral IE1 that is facilitated by coiled coil domains, and the interaction with IE1 is important for Bin8 function. Ac16 also forms a complex with viral FP25 and cellular actin and associates with membranes via palmitoylation. These data suggested that this gene family encodes a multifunctional protein that accomplishes specific needs of group INPVs.     

基因工程雄性不育烟草及其温度敏感性

将含有抗溴苯腈基因bxn和雄性不育基因的重组载体pTA29-Barnase/bxn导入农杆菌(Agrobacterium tumefaciens)后转化烟草(Nicotiana tabacum L.),得到33个转基因植株。在27℃/23℃培养的16株中,有7株表现部分不育,另9株全部可育。而在20℃/15℃培养的17株中,12株表现不育,5株表现部分不育。部分不育的植株上同时开放可育花朵和不育花朵,不过其中的不育花朵中的花粉萌发活力很低。将在20℃/15℃条件下表现不育的12个不育株从20℃/15℃温室移至27℃/23℃温室后30d左右,其中9株表现程度不同的育性恢复现象:5株表现部分可育,另4株表现完全可育;但仍有3株表现雄性不育。雄性不育花朵的花丝变短,花药皱瘪,不散粉。细胞学观察证明,转基因植株的花药绒毡层降解提早于四分体时期,至单核小孢子时期降解殆尽。     

灰葡萄孢丝裂原活化蛋白激酶编码基因bmp1和bmp3的功能

【背景】植物病原真菌丝裂原活化蛋白激酶(Mitogen-activated protein kinase,MAPK)信号途径参与病菌有性生殖、细胞壁完整、菌丝侵染、致病力、胁迫响应等过程,灰葡萄孢MAPK信号途径参与病菌生长发育、致病力以及胁迫响应,但MAPK信号途径基因在灰葡萄孢中的功能尚未完全阐明,该信号途径对灰葡萄孢的生长发育和致病力的调控机制尚不明确。【目的】明确灰葡萄孢MAPK编码基因bmp1、bmp3在病菌生长发育、致病力以及氧化胁迫响应过程的功能,为进一步阐明MAPK信号途径调控灰葡萄孢生长发育和致病力的分子机制奠定基础。【方法】利用RNAi技术构建灰葡萄孢MAPK编码基因bmp1和bmp3的RNAi突变体,并以野生型BC22菌株为对照,对bmp1和bmp3基因的RNAi突变体的表型、致病力以及对氧化胁迫的敏感性进行分析。【结果】灰葡萄孢bmp1和bmp3基因的RNAi突变体其菌落形态、菌丝形态均与野生型BC22菌株没有明显差别;bmp1基因的RNAi突变体生长速率明显减慢,分生孢子产量明显降低;bmp3基因的RNAi突变体的生长速率与野生型BC22菌株没有明显差别,不能产生分生孢子。bmp1和bmp3基因的RNAi突变体在番茄果实的表面均不能产生明显的致病症状,而且不能穿透玻璃纸。bmp1基因的RNAi突变体在含有H_2O_2的培养基上受抑制的程度显著低于野生型,而在含甲萘醌的培养基上受抑制的程度显著高于野生型;bmp3基因的RNAi突变体在含有H_2O_2和甲萘醌的培养基受抑制的程度均显著高于野生型。【结论】灰葡萄孢bmp1基因正调控病菌生长、分生孢子形成、致病力和穿透能力,参与调控病菌对氧化胁迫的响应;灰葡萄孢bmp3基因正调控病菌分生孢子形成、致病力、穿透能力以及对氧化胁迫的响应。     

茉莉酸作用的分子生物学研究

茉莉酸及其衍生物茉莉酸甲酯等统称为茉莉酸盐,是广泛存在于植物中的一种生长调节物质,在植物细胞中起着非常重要的作用,介绍了茉莉酸生物合成过程中关键酶基因的克隆、表达及调控,并对茉莉酸的一些突变体进行了分析,结果显示茉莉酸在发育及防御尤其是在雄性不育及抗病虫害方面起着非常重要的作用,同时综述了茉莉酸信号转导的最新成果。     

植物生长素极性运输调控机理的研究进展

生长素极性运输特异地调控植物器官发生、发育和向性反应等生理过程。本文综述和分析了生长素极性运输的调控机制。分子遗传和生理学研究证明极性运输这一过程是由生长素输入载体和输出载体活性控制的。小G蛋白ARF附属蛋白GEF和GAP分别调控输出载体(PIN1)和输入载体(AUX1)的定位和活性, 并影响高尔基体等介导的细胞囊泡运输系统, 小G蛋白ROP也参与输出载体PIN2活性的调节。本 文基于作者的研究工作提出小G蛋白在调控生长素极性运输中的可能作用模式。     

MiR-204 regulates cardiomyocyte autophagy induced by ischemia-reperfusion through LC3-II

Background  

Autophagy plays a significant role in myocardial ischemia-reperfusion (IR) injury. So it is important to inhibit autophagy to protect cardiomyocytes besides anti-apoptosis. MiRNA has been demonstrated to protect cardiomyocytes against apoptosis during IR, while whether it has anti-autophagy effect has not been known. The aim of this study was to investigate whether miR-204 regulated autophagy by regulating LC3-II protein, which is the marker of autophagosome during myocardial IR injury.     

Removing environmental organic pollutants with bioremediation and phytoremediation

Hazardous organic pollutants represent a threat to human, animal, and environmental health. If left unmanaged, these pollutants could cause concern. Many researchers have stepped up efforts to find more sustainable and cost-effective alternatives to using hazardous chemicals and treatments to remove existing harmful pollutants. Environmental biotechnology, such as bioremediation and phytoremediation, is a promising field that utilizes natural resources including microbes and plants to eliminate toxic organic contaminants. This technology offers an attractive alternative to other conventional remediation processes because of its relatively low cost and environmentally-friendly method. This review discusses current biological technologies for the removal of organic contaminants, including chlorinated hydrocarbons, focusing on their limitation and recent efforts to correct the drawbacks.     

光合作用系统II外周蛋白——P23k去折叠的热力学和动力学

利用荧光光谱学等方法结合高压力技术研究了光合作用系统II中的一个外周蛋白——— 2 3kD(以P2 3k表示 )蛋白的去折叠。热力学研究表明 ,在 2 0℃、180MPa(1MPa =10 .0大气压 )可使该蛋白质完全去折叠 ,而在3℃ ,16 0MPa即可使该蛋白质完全去折叠 ,这是迄今为止有关研究中最易被高压力去折叠的一个蛋白质。在2 0℃ ,该蛋白质在常压下去折叠反应的标准自由能与标准体积变化分别为 2 3.4 5kJ mol和 - 15 0 .3ml mol;动力学研究揭示该蛋白质的折叠反应的活化体积ΔV f 为正值 (84 .1ml mol) ,而去折叠反应的活化体积ΔV u 为负值(- 6 6 .2ml mol)。在常压下 ,折叠和去折叠反应的速度常数 (K0f,K0u)分别为 1.87s- 1 和 1.3× 10 - 4s- 1 ,这些结果为解释该蛋白质易被压力去折叠提供了线索     

Detection of gene mutations related with drug resistance in Mycobacterium leprae from leprosy patients using Touch-Down (TD) PCR

The lack of methods to identify Mycobacterium leprae with the resistance against multi-drugs quickly and specifically has hindered effective chemotherapy against M. leprae infection. To screen M. leprae with resistance against multi-drugs, the Touch-Down (TD)-PCR has been used in this study. Sequences of the folP, rpoA, B, and gyrA, B genes were analyzed for isolates of M. leprae from leprosy patients in Korea. We amplified designated region of several genes in M. leprae involved in drug resistance and could obtain the PCR products of each gene. The mutations in the particular region of folP, rpoB, and gyrB gene were certified by TD-PCR single-stranded conformational polymorphism and DNA sequencing, respectively.