Variability of communities and physiological characteristics between free-living bacteria and attached bacteria during the PAH biodegradation in a soil/water system   总被引：1，自引：0，他引：1  

Yi-Tang Chang  Jiunn-Fwu Lee  Huan-Ping Chao 《European Journal of Soil Biology》2007,43(5-6):283

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) via free-living and attached micro-organisms in soil/water systems was observed in order to examine the variability in the community dynamics and physiological profiles of the micro-organisms. As determined by fluorescence in situ hybridization (FISH), the Domain Bacteria, consisting of three phyla α-, β- and γ-Proteobacteria, reached 41.27–56.05% of all organisms in the soil/water system for PAH biodegradation. Among the free-living species, Proteobacteria, including Brevundimonas (Pseudomonas) diminuta, Caulobacter spp., Mycoplana bullata, Acidovorax spp. and Pseudomonas aeruginosa were found to be dominant—making up 93.51–99.80% of the population—and therefore seem to be associated with PAH biodegradation. Total plate count numbers and the count of Pseudomonas sp. present in the free-living population increased to between 10³ and 10⁶ CFU ml⁻¹ when clay with very low organic matter content was used as the matrix for PAH degradation. However, total plate count microbial numbers increased to only 10¹–10² CFU ml⁻¹ using natural soil from Taichung containing 1.883% organic matter. The soil organic content (SOM) seemed to affect the mass transfer of PAH in soil, leading to the difference in PAH biodegradation. Two different approaches, which included community-level physiological profiling (CLPP) and ectoenzymatic activities, were used to explain the functional diversity between free-living and attached bacteria. The free-living and attached bacterial communities from the clay system showed proportionately greater differences using CLPP. Relatively high levels of esterases, aminopeptidases and some specific glycolysis-gluconeogenesis enzymes gave an identifiable correlation with PAH biodegradation. The differences in bacterial composition, numbers and physiological characteristics show that free-living and attached micro-organisms may play different biochemical roles in PAH degradation in soil.  相似文献   

Grazing of a common species of soil protozoa (Acanthamoeba castellanii) affects rhizosphere bacterial community composition and root architecture of rice (Oryza sativa L.)     

K. Kreuzer  M. Iijima  S. Scheu 《Soil biology & biochemistry》2006,38(7):1665-1672

We performed a controlled experiment with rice seedlings (Oryza sativa L.) growing in Petri dishes on homogeneous nutrient agar containing a simple rhizosphere food web consisting of a diverse bacterial community and a common soil protozoa, Acanthamoeba castellanii, as bacterial grazer. Presence of amoebae increased bacterial activity and significantly changed the community composition and spatial distribution of bacteria in the rhizosphere. In particular, Betaproteobacteria did benefit from protozoan grazing. We hypothesize that the changes in bacterial community composition affected the root architecture of rice plants. These effects on root architecture affect a fundamental aspect of plant productivity. Root systems in presence of protozoa were characterized by high numbers of elongated (L-type) laterals, those laterals that are a prerequisite for the construction of branched root systems. This was in sharp contrast to root system development in absence of protozoa, where high numbers of lateral root primordia and short (S-type) laterals occurred which did not grow out of the rhizosphere region of the axile root. As a consequence of nutrient release from grazed bacteria and changes in root architecture, the nitrogen content of rice shoots increased by 45% in presence of protozoa. Our study illustrates that interactions over three trophic levels, i.e. between plants, bacteria and protozoa significantly modify root architecture and nutrient uptake by plants.  相似文献   

转基因大麦的gfp基因表达及染色体定位     

陈建民  黄洁  赵梅香  仇丽红  洪义欢  王幼平 《麦类作物学报》2006,26(6):1-5

为了深入探讨转基因的整合位置对基因表达的影响，对转绿色荧光蛋白基因（gfp）大麦的荧光表达和gfp基因的染色体位置进行了研究。结果表明，绿色荧光蛋白（gfp）在大麦的根尖和花粉中均有表达，四倍体的荧光表达强度大于二倍体，表现出基因的剂量效应。gfp基因插入到第6染色体（6H）短臂和另一染色体的短臂近末端。  相似文献   

Several Influencing Factors on Fluorescent in situ Hybridization Experimental System Applied to Dendranthema spp.     

WangWenkui LiMaoxuet XuYingxiu DaiSilan 《中国林学(英文版)》2003,5(2):30-34

Fluorescent in situ hybridization (FISH) was applied to investigate the phylogenetic relationship among Dendranthema spp. Genomic DNA of wild species which was used as probe did not give specific signals, while 18S-26S rDNA from Arabidopsis, which was used as control probe, showed the loci on the target chromosomes clearly. Satisfied results of FISH were gotten when denaturing digoxingenen-labeled probe and chromosome together in oven at 80℃ for 10-15min. There is little influence on the result by the stringency of washing when rDNA was used as probe. The result also indicates the limitation of genomic in situ hybridization (GISH) when used as an approach to analyze the phylogenetic relationship among Dendranthema spp. and the origin of cultivated chrysanthemum.  相似文献   

The Cloning and Fluorescence In situ Hybridization Analysis of Cotton Telomere Sequence     

LING Jian  CHENG Hua  LIU Fang  SONG Guo-li  WANG Chun-ying  LI Shao-hui  ZHANG Xiang-di  WANG Yu-hong  WANG Kun-bo 《中国农业科学(英文版)》2012,(9):1417-1423

  相似文献   

大白菜延伸DNA纤维的制备和检测(英文)     

李九欢  王彦华  李晓峰  申书兴  轩淑欣 《农业科学与技术》2012,(3):517-519,591

[目的]制备和检测大白菜延伸DNA纤维。[方法]以大白菜幼叶为材料,采用刀切分离细胞核、SDS释放DNA、盖玻片滑动牵拉DNA的方法,首次获得大白菜DNA延伸纤维。[结果]以基因组DNA和25SrDNA为探针进行原位杂交检测,该DNA纤维长度大约为1.93Mb,25SrDNA在大白菜基因组中的拷贝数在258-687之间。该方法获得的DNA延伸纤维平行、清晰、适合FISH分析。[结论]该研究将会促进大白菜基因图谱的构建和组织分析。  相似文献   

广宁红花油茶根尖压片制作技术     

李永泉  陈清凤  张应中  丁晓纲  蔡坚  刘喻娟 《广东林业科技》2012,28(2):22-25

广宁红花油茶在广东、广西等原生地种植容易获得高产,具有良好的遗传改良潜力。文章以广宁红花油茶为对象,探索了适用于荧光原位杂交技术中的染色体制片技术,并与传统的染色体压片制作技术进行比较,总结了一套节省时间、技术要求较低和效果较好的染色体根尖压片制作技术,可用于广宁红花油茶的细胞学研究,为开展分子染色体工程育种以及基因组分析奠定技术基础。  相似文献   

珍珠豆型花生品种白沙1016核型分析   总被引：1，自引：0，他引：1  

杜培  张新友  李丽娜  黄冰艳  董文召  汤丰收 《中国油料作物学报》2013,35(3)

珍珠豆型花生白沙1016是重要的花生种质资源.利用高度保守的重复序列5S和45SrDNA作探针对白沙1016根尖细胞中期染色体进行荧光原位杂交(FISH)分析,发现两探针在白沙1016的12条染色体上能产生杂交信号,其中1对染色体长臂与短臂、2对染色体短臂、3对染色体长臂具有杂交信号.综合DAPI+染色带纹和染色体长度、臂比、面积等特征,可以将白沙1016大部分染色体区分开,为白沙1016的育种利用提供了染色体遗传分析基础.  相似文献   

Search for Borrelia burgdorferi in kidneys of dogs with suspected "Lyme nephritis"     

Hutton TA  Goldstein RE  Njaa BL  Atwater DZ  Chang YF  Simpson KW 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(4):860-865

BACKGROUND: "Lyme nephritis" is a poorly characterized condition associated with proteinuria and often fatal renal failure in dogs with serological evidence of infection with Borrelia burgdorferi. OBJECTIVE: The aim of this study was to determine if intact B. burgdorferi organisms were present in the kidneys of serologically Lyme-positive dogs with histopathologic features of Lyme nephritis. ANIMALS: Twenty-six affected and 10 control dogs were identified over an 8-year period (1996-2004) in databases at Cornell University's College of Veterinary Medicine. Case inclusion required serologic evidence of natural exposure to B. burgdorferi and availability of renal tissue (frozen or paraffin embedded) exhibiting pathology consistent with Lyme nephritis. METHODS: Renal tissue samples were assessed using modified Steiner (silver) (MS) staining, immunohistochemistry (IHC), polymerase chain reaction (PCR) using 4 primer sets (eubacterial, B. burgdorferi, Bartonella, and canine genomic DNA), and fluorescence in situ hybridization (FISH) using a 5'-cy3-eubacterial probe for 16S rRNA. RESULTS: MS stain was positive in 1 case; IHC was negative in all cases. None of the B. burgdorferi or Bartonella PCR reactions was positive. Two of the B. burgdorferi FISH analyses were positive. CONCLUSIONS AND CLINICAL IMPORTANCE: Minimal evidence of the presence of intact B. burgdorferi or any other bacterial organism was found in the renal tissue of dogs with suspected Lyme nephritis. Direct renal invasion by B. burgdorferi organisms does not appear to be responsible for this syndrome.  相似文献   

黄瓜倍性材料创制及染色体组成的FISH鉴定     

管苇  张云霞  杨树琼  陈劲枫  娄群峰 《中国农业科学》2014,47(17):3513-3522

【目的】黄瓜（Cucumis sativus L.）遗传基础狭窄,种质资源多样性较为有限,遗传育种研究相对落后。本试验旨在创制整倍体和非整倍体黄瓜种质材料,建立其准确的染色体组成鉴定方法,为进一步选育黄瓜各种染色体系、目标性状的染色体定位及遗传育种研究奠定基础。【方法】以华北生态型黄瓜‘长春密刺’的高代自交系为材料,0.4％秋水仙素溶液处理萌动种子,诱导染色体数目加倍。为获得同源三倍体材料,以诱导获得的同源四倍体为母本,二倍体为父本进行杂交,授粉35-45 d后采收成熟果实进行胚拯救。采用染色体计数,结合形态学、叶片气孔电镜观察,对诱导株及杂交后代的倍性进行鉴定。利用染色体特异的探针进行荧光原位杂交（fluorescence in situ hybridization,FISH）,通过观察特异探针在染色体上杂交信号的数目、强弱及位置,结合黄瓜的染色体形态参数,对诱导株的染色体组成进行鉴定。【结果】对经秋水仙素处理的‘长春密刺’材料进行有丝分裂中期染色体计数观察,结果显示诱导获得8株四倍体（2n=28）,3株非整倍体（2n=16,19,27）材料。将四倍体与二倍体杂交获得了三倍体材料（2n=21）。经荧光原位杂交分析,根据黄瓜着丝粒探针Type III和核糖体45S rDNA两类信号在染色体上的信号特征可以看出,与二倍体相比,三倍体与四倍体上杂交信号为倍性变化关系,进一步验证创制出的整倍性材料为三倍体与四倍体。不同倍性‘长春密刺’植株的形态学特征存在一定差异,四倍体植株的形态指标与二倍体差异显著;三倍体植株与二倍体在形态学上差异不显著;非整倍体植株与二倍体在形态学上差异也不显著,但其长势较二倍体弱,且花期推迟,雌雄花花期不遇,坐果率明显低于二倍体。经叶片气孔电镜观察,‘长春密刺’二倍体、三倍体与四倍体植株叶片气孔的大小与密度均存在差异,随着倍性提高,气孔的长度和宽度增加,而气孔密度则下降,说明形态学筛选和叶片气孔电镜观察可以作为鉴定黄瓜倍性的辅助方法。以上述两类黄瓜重复序列（Type III和45S rDNA）和染色体特异的单拷贝基因Csa006700为探针,对染色体数目为16的一株非整倍体诱导株进行染色体组成鉴定。重复序列的荧光原位杂交结果显示,额外的两条染色体为1号或2号染色体。进一步利用黄瓜2号染色体端部的基因Csa006700探针检测,发现该基因只在其中一对染色体上有信号,由此明确该材料为附加两条1号染色体的四体材料（2n=14+2）。研究表明秋水仙素不仅可直接诱导出同源多倍体,同时可诱导各种非整倍体植株。【结论】利用秋水仙素处理黄瓜萌动种子,诱导染色体倍性的变化,结合染色体特异探针的荧光原位杂交鉴定,可快速创制并筛选出各种染色体组成的特异新种质。  相似文献