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91.
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以线粒体功能性蛋白替代氧化酶(alternative oxidase,AOX)为研究对象,对隐孢子虫(Cryptosporidium)分离株进行扩增和测序,并对测得的序列进行种系发育关系研究,以确定不同隐孢子虫分离株之间的进化关系,并以18SrRNA和HSP70基因构建的进化树作参照,评价AOX基因是否适合作隐孢子虫基因分型和进化关系分析的基因座。结果表明,在AOX序列构建的进化树上Cryptosporidum分为两大类:Cryptosporidium baileyi和C.meleagridis处于一个进化枝上,C.hominis、C.suis、C.parvum牛基因型和C.parvum鼠基因型处于另一个进化枝上。在C.parvum内,鼠基因型分离株和猪基因I型(即C.suis)分离株与牛基因型和人基因型(即C.hominis)在AOX基因序列上都存在着差异。鹌鹑源C.meleagridis分离株与禽源C.baileyi3个分离株在AOX基因序列的同源性显著高于前者与C.parvum的同源性,在进化树上C.meleagridis与C.baileyi的亲缘关系也较其与C.parvum密切。AOX基因不仅可作为隐孢子虫分离株种系发育的遗传标记,又为发现隐孢子虫新的遗传特性提供了一种途径。 相似文献
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Katia Duquesne Aurlie Lieutaud Jeanine Ratouchniak Andrs Yarzbal Violaine Bonnefoy 《European Journal of Soil Biology》2007,43(5-6):351
Weathering of the arsenopyrite-rich tailings of the Carnoulès abandoned mining site (Gard, France) results in the formation of acid mine waters heavily loaded with arsenic. Dissolved arsenic present in the seepage waters is precipitated within a few meters from the bottom of the tailing dam by microorganisms. From these effluents, we have isolated and characterized a Gram negative bacterium involved in this bioremediation process. This bacterium, which belongs to the Thiomonas genus, is very efficient in removing arsenite from contaminated acidic waters by oxidizing it to arsenate, which precipitates. 相似文献
95.
为探讨毕节小檗(Berberis guizhouensis)2个居群的遗传变异性和相似性,用聚丙酰胺垂直板凝胶电泳技术对毕节小檗2个居群的细胞色素氧化酶(COD)同工酶和过氧化物酶(POD)同工酶进行研究。结果表明,毕节小檗2个居群20株植株POD同工酶酶带数为8条,其中有4条共同酶带(POD-3、POD-5、POD-7、POD-8);COD同工酶酶带数为7条,其中也有4条共同酶带(COD-3、COD-5、COD-6、COD-7)。不同居群的同工酶酶谱存在差异,同一居群的不同同工酶酶谱也存在差异;韭菜坪居群的分化程度大于艾家坪居群。 相似文献
96.
The role of Ca and Mg in the enzymatic browning of ‘Golden Delicious’ apples was explored. Enzymatic browning due to polyphenol oxidase (PPO) was stimulated with the addition of 0.8–10 mM MgCl2 to the reaction mixture, whereas 0.8–10 mM CaCl2 had little effect or decreased the rate of enzymatic browning. Within a week after vacuum infiltration with MgCl2, treated fruits exhibited browning symptoms that were similar to bitter pit. Six months after vacuum infiltration, when analyzed for enzyme activity, MgCl2-treated fruits exhibited higher rates of PPO activity, whereas CaCl2-treated fruits had lower activity than the MgCl2-treated fruits and the controls. A hypothesis is advanced that the initial visible symptoms of bitter pit, i.e. the localized browning, is caused by PPO, its activity being stimulated by the localized Mg/Ca imbalance present in the tissue. The results indicate that Ca is predominant in the prevention of this disorder, whereas a deficiency of Ca is involved in its induction. 相似文献
97.
桑属几个种及品种细胞色素氧化酶同工酶的研究 总被引:4,自引:1,他引:3
用聚丙烯酰胺凝胶电泳的方法,对四川桑属植物的6个种、两个品种及两个引进种的细胞色素氧化酶同工酶进行了研究。结果:(1)桑属内有共同的特征酶带;(2)桑属内各种、品种间的酶谱有显著差异,每个种都有不同的特征酶谱;(3)用组平均聚类法研究同工酶分类,在桑属植物分类上有一定的适用价值;(4)上述研究结果与过氧化物酶同工酶的排序法分类比较,除华桑有差异外,其它桑种、品种均表现规律性的一致倾向,为桑属植物分类提供了新的依据。 相似文献
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99.
Anastasios I. Darras Vasilios DemopoulosChrysovalanti Tiniakou 《Postharvest Biology and Technology》2012,64(1):168-174
UV-C (λ = 254 nm) irradiation was effective in reducing Botrytis cinerea floret specking (i.e., lesion development) and maintaining a better postharvest quality of cut gerbera flowers. A range of UV-C doses (0.5-10.0 kJ m−2) was tested on ‘Ice cream’ and ‘Ecco’ gerbera flowers to activate germicidal and inducible defence mechanisms. Irradiation of B. cinerea cultures with 0.5, 1.0, 2.5 and 5.0 kJ m−2 UV-C resulted in up to a 10-fold reduction of conidial germination percentages and significant (P < 0.05) delay of mycelium growth, compared to the non-irradiated control cultures. Moreover, lesion diameters on gerbera florets inoculated with UV-C irradiated B. cinerea cultures were reduced by up to 70%, suggesting that UV-C had a negative effect on the pathogenic strength of the fungi. Lesion diameters on florets of UV-C irradiated gerberas were reduced by up to 55% giving evidence that defence responses in the host tissue were induced. Concentration of total phenolics seemed to be unaffected by 0.5 kJ m−2 UV-C treatment in both cultivars, but polyphenol oxidase (PPO) activity increased and remained higher compared to the non-irradiated control flowers throughout the 48 h storage period at 20 °C. The increase of PPO suggests that this enzyme might play an important role in host defence mechanisms that suppressed B. cinerea floret specking. Gerbera flowers irradiated with 1.0 or 10.0 kJ m−2 UV-C showed improvement in vase-life by 1.8 and 2.4 d, decrease in stem break percentages by 43 and 29% and delay in stem break incidence by 3.3 and 1.3 d, respectively. 相似文献
100.