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91.
A reproducible approach to improve salt tolerance of conifers has been established by using the technology of plant genetic transformation and using loblolly pine (Pinus taeda L.) as a model plant. Mature zygotic embryos of three genotypes of loblolly pine were infected with Agrobacterium tumefaciens strain LBA 4404 harboring the plasmid pBIGM which carrying two bacterial genes encoding the mannitol-1-phosphate dehydrogenase (Mt1D, EC 1.1.1.17) and glucitol-6-phosphate dehydrogenase (GutD) (EC 1.1.1.140), respectively. Transgenic plantlets were produced on selection medium containing 15 mg l(-1) kanamycin and confirmed by polymerase chain reaction (PCR) and Southern blot analysis of genomic DNA. The Mt1D and GutD genes were expressed and translated into functional enzymes that resulted in the synthesis and accumulation of mannitol and glucitol in transgenic plants. Salt tolerance assays demonstrated that transgenic plantlets producing mannitol and glucitol had an increased ability to tolerate high salinity. These results suggested that an efficient A. tumefaciens-mediated transformation protocol for stable integration of bacterial Mt1D and GutD genes into loblolly pine has been developed and this could be useful for the future studies on engineering breeding of conifers. 相似文献
92.
野生罗汉果遗传多样性的ISSR分析 总被引:19,自引:0,他引:19
应用ISSR分子标记方法对采自广西和广东的7个罗汉果(Siraitia grosvenorii)野生居群共130个个体进行了遗传多样性分析。15个ISSR引物共扩增到了111个位点,其中91个是多态性位点,占82.0%。Nei′s基因多样性指数(He)为 0.248,Shannon 信息多样性指数(I) 为0.354。罗汉果不同居群的遗传多样性水平差异较大,居群多态位点百分率在 28.2%-55.6%之间,Nei′s基因多样性指数为0.080-0.209,Shannon 信息多样性指数为0.123-0.310。永福居群(YF)和金秀居群(JX)的遗传多样性水平较高,其周边居群的遗传多样性水平逐渐降低,居群间产生了较大的遗传分化(Gst = 0.569)。居群间的遗传距离与地理距离相关性不明显(r =0.369,P = 0.115)。UPGMA聚类图中,7个居群的个体按居群各自聚在一起。 相似文献
93.
人工湿地是为了净化污水而建造的一类系统,其环境特征既不同于自然湿地,也不同于一般陆地生境。人工湿地的生物多样性是一个新问题。作者以杭州植物园作为案例研究了亚热带地区人工湿地植物多样性的季节变化。结果表明:秋末人工湿地的物种数为72种,其中自然迁入植物54种;冬春季的物种数为46种,其中自然迁入物种33种。在人工湿地中,人工配置的植物种类仍然是群落结构的主体,迁入植物大部分处于伴生地位。应该在人工配置植物的基础上保留一些有价值的自然迁入植物,使人工湿地具有较高的生物多样性,这样既能充分吸收水中的多种营养成分,又能美化环境。亚热带地区可以有冬春和夏秋两个植物功能群在人工湿地中连续生长,这可以充分利用时间生态位,提高人工湿地在冬季的净化效果,增强人工湿地净化能力的季节间稳定性。 相似文献
94.
High-Temperature Fluorescent In Situ Hybridization for Detecting Escherichia coli in Seawater Samples, Using rRNA-Targeted Oligonucleotide Probes and Flow Cytometry 总被引:1,自引:0,他引:1 下载免费PDF全文
Fluorescence in situ hybridization (FISH) is a widely used method to detect environmental microorganisms. The standard protocol is typically conducted at a temperature of 46°C and a hybridization time of 2 or 3 h, using the fluorescence signal intensity as the sole parameter to evaluate the performance of FISH. This paper reports our results for optimizing the conditions of FISH using rRNA-targeted oligonucleotide probes and flow cytometry and the application of these protocols to the detection of Escherichia coli in seawater spiked with E.coli culture. We obtained two types of optimized protocols for FISH, which showed rapid results with a hybridization time of less than 30 min, with performance equivalent to or better than the standard protocol in terms of the fluorescence signal intensity and the FISH hybridization efficiency (i.e., the percentage of hybridized cells giving satisfactory fluorescence intensity): (i) one-step FISH (hybridization is conducted at 60 to 75°C for 30 min) and (ii) two-step FISH (pretreatment in a 90°C water bath for 5 min and a hybridizing step at 50 to 55°C for 15 to 20 min). We also found that satisfactory fluorescence signal intensity does not necessarily guarantee satisfactory hybridization efficiency and the tightness of the targeted population when analyzed with a flow cytometer. We subsequently successfully applied the optimized protocols to E. coli-spiked seawater samples, i.e., obtained flow cytometric signatures where the E. coli population was well separated from other particles carrying fluorescence from nonspecific binding to probes or from autofluorescence, and had a good recovery rate of the spiked E. coli cells (90%). 相似文献
95.
猕猴桃RNA提取与RT-PCR 总被引:1,自引:0,他引:1
为了从富含多糖和多酚等物质的猕猴桃幼叶中提取和分离出高质量的RNA,用多个不同品种的猕猴桃叶为材料,比较了3种不同的RNA提取方法所提取的总RNA。结果表明,用胍-酚酸-DEPC法提取的RNA质量最好,提取率达到682.9~780.8μg?g(FW),其R值(A260?A280)接近1.90。用所提取的RNA样品进行RT-PCR,其扩增产物在琼脂糖凝胶上出现明显清晰的扩增cDNA带,说明RNA样品在纯度和浓度上都可以满足PCR等分子生物学实验的基本要求。 相似文献
96.
The effects of proteasome inhibitor lactacystin on mouse oocyte meiosis and first cleavage 总被引:1,自引:0,他引:1
TAN Xin PENG An WANG Yongchao & TANG Zuoqing . School of Life Sciences Technology Beijing Institute of Technology Beijing China . College of Life Sciences Beijing Normal University Beijing China . College of Basic Medicine Capital University of Medical Sciences Beijing China 《中国科学:生命科学英文版》2005,48(3):287-294
Many studies have shown that the ubiq-uitin-proteasome pathway (UPP) for the degradation of short-lived proteins plays a key role in regulating cell cycle progression[1—3]. At least two distinct prote-olytic pathways are required for cell cycle process. The first pathway promotes transition from G1 to S phase, and the second initiates the onset of anaphase and exit from mitosis. The inhibition of UPP will re-sult in the blockage of cell cycle process. The knowl-edge of the role of UPP in… 相似文献
97.
Molecular and morphological data suggest that Spinibarbus caldwelli (Nichols) (Teleostei: Cyprinidae) is a valid species 总被引:1,自引:0,他引:1
The taxonomic problem of the cyprinid species of genus Spinibarbus, occurring in southern China and northern Vietnam, was resolved on the basis of molecular and morphological analyses. Spinibarbus caldwelli and Spinibarbus hollandi have a smooth posterior edge of the last unbranched dorsal fin ray among species in the genus. Spinibarbus caldwelli is currently regarded as a junior synonym of S. hollandi because of ambiguities in diagnostic characters. In this article, 11 mtDNA cytochrome b sequences of Spinibarbus specimens were analyzed together with Barbodes gonionotus and Puntius conchonius as outgroups. Our results showed that specimens identified as S. hollandi from Taiwan were different from those from the Asian mainland at a high level of genetic divergence (0.097–0.112), which is higher than that between the two valid species, S. sinensis and S. yunnanensis (0.089), and suggested that Taiwan specimens should be considered as a different species from the Asian mainland one. In a molecular phylogenetic analysis, the sister-group relationship between Taiwan specimens and the Asian mainland specimens was supported strongly by a high confidence level (100% in bootstrap value). Further analysis of morphological characters showed that overlap of diagnostic characters is much weaker than previously suggested. Taiwan specimens had 8 branched rays in the dorsal fin, whereas those from the mainland had almost 9–10. The molecular and morphological differences suggest S. caldwelli to be valid. The molecular divergence shows the genetic speciation of S. hollandi and S. caldwelli might have occurred 5.6–4.9 million years ago; the former could be a relict species in Taiwan, and the latter dispersed in the Asian mainland. 相似文献
98.
Chuanyi Yao Shaokun Tang Zhimin He Xu Deng 《Journal of Molecular Catalysis .B, Enzymatic》2005,35(4-6):108-112
The kinetics of lipase-catalyzed hydrolysis of olive oil in AOT/isooctane reversed micellar media was studied. It was shown that the deactivation of lipase had a great influence on the reaction kinetics. Based on whether the enzyme deactivation and influences of both product and substrate on enzyme stability were included or not, four different kinetic models were established. The simulating results demonstrated that the kinetic model, which including product inhibition, enzyme deactivation and the improvements of lipase stability by both product and substrate, fit the experimental data best with an overall relative error of 4.68%. 相似文献
99.
Tang Wei Newton Ronald J. 《Molecular breeding : new strategies in plant improvement》2005,16(3):235-246
Mature zygotic embryos of recalcitrant Christmas tree species Fraser fir [Abies fraseri (Pursh) Poir], and Nordmann fir (Abies nordmanniana L.k.), and Virginia pine (Pinus virginiana Mill.) were used as explants for Agrobacterium tumefaciens strain GV3850-mediated transformation using the gfp (green fluorescent protein) gene as a reporter. Factors including media used for inoculation and co-cultivation, concentrations
of acetosyringone, and antibiotics in tissue culture media have been evaluated. A high transformation frequency was obtained
on TE medium containing 50μM acetosyringone and using 500 mg/l timentin to eliminate bacteria. Transient gene expression was
observed in all three Christmas tree species, but transgenic plants were only produced from Virginia pine. Stable integration
and expression of transgenes in the plant genome of Virginia pine was confirmed by polymerase chain reaction (PCR), Southern
and northern blot analyses. These results demonstrated that a stable transformation system has been established in Virginia
pine and this system would provide an opportunity to transfer economically important genes into Christmas tree species. 相似文献
100.
鞘内注射M受体和GDNF反义寡脱氧核苷酸抑制吗啡戒断大鼠蓝斑c—Fos表达 总被引:3,自引:0,他引:3
Hui Fen Liu Wen Hua Zhou Shuai En Tang Miao Jun Lai Sheng Liu Wei Sheng Chen Guo Dong Yang 《实验生物学报》2005,38(3):211-218
The antisense approach and immunohistochemistry were used to study the effects of different muscarinic receptor (M) subtypes and glial cell derived neurotrophic factor (GDNF) on the scores of morphine-withdrawal syndrome and the expression of c-Fos in locus coeruleus (LC). Intrathecal injection of M2 receptor antisense oligonucleotides (M2AS-oligo) or GDNF antisense oligonucleotides (GDNFAS-oligo) decreased the scores of morphine withdrawal syndrome. The expression of c-Fos positive neurons in the LC increased in morphine-dependent rats and increased to a greater extent after the injection of naloxone (4mg/kg, ip) in morphine dependent rats. Intrathecal injection of M2AS-oligo or GDNFAS-oligo inhibited the increase of c-Fos expression in LC during morphine withdrawal, but there was no effect in case of M1AS-oligo. The results suggest that M2 receptor of spinal cord mediates the neural activation of LC during morphine withdrawal. And the interaction between neurons and glial cells may be involved in the ascending activation process. 相似文献