基因芯片在百合无症病毒检测中的应用

设计百合无症病毒、植物18SrRNA基因的特异扩增引物和各种对照的探针，将探针固定在醛基化玻璃片基上，完成植物基因芯片制备。提取百合种球总RNA，经RT-PCR扩增相应区段并用Cy3dCTP进行标记，用标记的PCR产物与芯片杂交，扫描仪对杂交结果进行扫描，GenePixProd．0软件对杂交图像进行分析。结果从荷兰进口的百合种球中检测出百合无症病毒，证明了该实验研制的植物病毒基因芯片的准确性和灵敏性。     

兰花5种病毒可视化基因芯片检测方法建立

为建立运用可视基因芯片技术快速、准确检测兰花病毒的方法,选择黄瓜花叶病毒、齿舌兰环斑病毒、建兰花叶病毒编码外壳蛋白(coat protein,CP)基因、辣椒褪绿病毒编码核衣壳蛋白N基因、落葵皱纹花叶病毒编码CI蛋白基因为目标基因,设计引物和探针(5'标记一段poly T)。利用多重RT-PCR方法进行病毒核酸扩增,将扩增产物与固定于芯片的特异性探针杂交,经清洗、可视化显色后进行结果分析。在优化的检测条件下,本研究筛选出2组多重引物组合Cm(F2-R2a)、Ba(F1-R1);Or(F1-R1)、Cy(F2-R2)和Ca(F1-R1),5条特异性探针。所建立的可视基因芯片具有较好的特异性和重复性,可检测出病毒阳性质粒的量为不低于10~3拷贝·μL~(-1)。     

辣椒轻斑驳病毒葫芦岛分离物RNA杂交检测体系的建立

辣椒轻斑驳病毒(pepper mild mottle virus,PMMoV)可引起辣椒叶片以及果实的花叶和畸形症状,造成相当的经济损失。为了建立辣椒轻斑驳病毒的高特异性和灵敏度的分子检测体系,采用非放射性的化合物地高辛(DIG)标记检测PMMoV正义链的RNA探针,建立了该病毒Dot blot杂交和Northern blot杂交检测体系,并通过RT-PCR法验证了杂交体系的检测特异性。结果表明,RNA探针对PMMoV具有很高的检测特异性和灵敏度,适用于病毒的早期检测以及相关分子研究。     

实时荧光RT-PCR一步法检测苹果茎沟病毒

 根据苹果茎沟病毒(ASGV)各分离物外壳蛋白(CP)基因的保守序列,设计并合成1对特异性引物和1条TaqMan-MGB探针,建屯了对ASGV的实时荧光RT-PCR检测方法。TaqMan-MGB探针3'端具有小沟结合分子(Minor groove binder,MGB),提高了探针的Tm值,缩短了探针长度,解决了病毒各分离物之间基因组变异较大、难以找到较长一致的序列来设计探针的困难。该方法的检测灵敏度比常规RT-PCR电泳检测高约10倍,对于ASGV等在果树体内含量较低的病毒尤为适用。此方法快速、灵敏,整个检测过程完全闭管,无需PCR后处理。     

玉米褪绿斑驳病毒实时荧光RT-PCR检测方法研究

玉米褪绿斑驳病毒(Maize chlorotic mottle virus,MCMV)是我国对外公布的检疫性有害生物。本研究根据该病毒外壳蛋白基因的保守序列,设计得到特异性引物及Taqman荧光探针,建立了MCMV的实时荧光RT-PCR方法,并对其灵敏度与特异性进行了研究。该方法针对2个不同来源的毒株均能得到典型扩增曲线,而没有从小麦线条花叶病毒、玉米粗缩病毒和玉米矮花叶病毒的RNA得到扩增曲线,表明引物与荧光探针具有良好的特异性。针对玉米褪绿斑驳病毒RNA不同稀释度样品,实时荧光RT-PCR检测低限达到10-5稀释度,检测灵敏度要比普通RT-PCR高出100倍。因此,本研究建立的MCMV实时荧光方法具有特异性强、灵敏度高和快速有效的优点。     

实时荧光RT-PCR方法检测齿兰环斑病毒与建兰花叶病毒

齿兰环斑病毒（Odontoglossum ringspot virus, ORSV）与建兰花叶病毒（Cymbidium mosaic virus, CymMV）是严重危害兰科植物的2种主要病毒。本研究根据病毒不同分离株外壳蛋白基因的保守序列,分别设计了ORSV与CymMV各自的特异性引物与荧光探针,建立了基于TaqMan探针的实时荧光RT-PCR检测方法。该方法与酶联免疫检测方法相比,灵敏度提高104倍,具有快速、灵敏和高特异性的优点,适合对ORSV和CymMV的快速检测。应用该方法,从来自台湾的蝴蝶兰样品中检出齿兰环斑病毒。     

TaqMan探针双重实时荧光定量PCR法同步检测兰花中的建兰花叶病毒和齿兰环斑病毒

为建立一种同步定量检测建兰花叶病毒(cymbidium mosaic virus,CymMV)和齿兰环斑病毒(odontoglossum ringspot virus,ORSV)的高效检测方法,本研究根据CymMV和ORSV CP基因高度保守区分别设计引物和探针并筛选,获得156 bp和148 bp的靶标序列及对应的最优特异性引物探针组合,建立了基于TaqMan探针的双重实时荧光定量PCR方法。该方法最低检出限为1拷贝或6.2×10-3fg,最低稳定检出限为10拷贝或6.2×10-2 fg,是RT-PCR的10~100倍;构建的标准曲线线性关系良好,扩增效率分别为97.7%和100.2%,相关系数R2分别为1.000和0.999;对其他5种常见病毒均无扩增曲线,检测特异性强;批组内与批组间重复性试验Ct值变异系数≤0.60%,重复性和稳定性好。利用该方法和基因芯片法分别对4个种属的66个兰花样品进行方法验证,该方法相较于基因芯片法检出率提高了53.85%(CymMV)和162.5%(ORSV)。综上所述,本方法可同时高通量检测CymMV和ORSV 2种病毒靶基因,结果可靠,应用前景广阔,可为开展病毒精准鉴定、科学防控以及从源头遏制病毒传播提供技术支撑。     

利用两种方法检测苹果锈果类病毒

以克隆ASSVd的部分序列,通过RT-PCR成功合成了地高辛标记的cDNA探针,提取苹果和梨树枝条的总RNA,用斑点杂交技术对其进行了检测试验,结果表明,探针具有很高的灵敏度和特异性。地高辛标记的cDNA探针不与阴性对照枝条RNA以及感染PBCVd、AFCVd、ADFVd枝条总RNA发生杂交,仅与感染ASSVd样品的总RNA杂交。     

应用基因芯片检测烟草脆裂病毒

 Total RNA in tulips was extracted by Trizol method. Primers were designed according to the sequences of Tobacco rattle virus and 18S rRNA gene of plant. The corresponding sections were amplified by RT-PCR and the PCR products were labeled by Cy3-dCTP. The probes of plant virus, 18S rRNA gene and comparisons were designed and immobilized on chips. Labeled PCR products were hybridized with the probes and the signals were scanned by scanner and analyzed by GenePix Pro 4.0 software. Tobacco rattle virus was detected from tulips which were imported from Holand. The accuracy and sensitivity of the plant virus gene chip were proved.     

Detection of four calla potyviruses by multiplex RT-PCR using nad5 mRNA as an internal control

Dasheen mosaic virus (DsMV), Turnip mosaic virus (TuMV), Konjac mosaic virus (KoMV) and Zantedeschia mild mosaic virus (ZaMMV) are important potyviruses previously identified in calla lily plants in Taiwan. In order to save time and cost of virus detection, a multiplex RT-PCR assay was developed for these calla potyviruses. Specific primers for each virus were designed based on the sequences of 3′ terminal region of respective viruses. To prevent false negative results, a primer pair specific to plant mitochondrial nad5 mRNA was used to produce a 185-bp fragment as an internal control of RT-PCR. The specificities of primers were confirmed by means of simplex and multiplex PCR assays. Optimal primer concentration ratio was identified by multiplex PCR assay. Total RNAs purified from virus-infected plants were used directly or mixed in different combinations, and then tested by multiplex RT-PCR. The result indicated that the expected RT-PCR products could be specifically amplified and identified on the basis of their molecular sizes. The detection sensitivity of multiplex RT-PCR was 25–625 times higher than that of indirect-ELISA (I-ELISA) depending on the virus. When applied to field surveys, multiplex RT-PCR could detect more single as well as mixed infection samples than I-ELISA. Accordingly, our multiplex RT-PCR assay provides a simple, rapid and reliable method for multiple potyvirus detection in calla lily.     

地高辛标记的cDNA探针检测烟草花叶病毒、黄瓜花叶病毒及马铃薯Y病毒

 根据已发表的烟草花叶病毒(Tobacco mosaic virus,TMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)和马铃薯Y病毒(Potato virus Y,PVY)的外壳蛋白基因序列,设计特异引物,分别以提取的TMV、CMV和PVY侵染的病叶总RNA为模板,反转录PCR进行体外扩增,分别得到长度为0.44、0.77、0.80 kb的目的片段,并克隆到pGEM-T easy质粒载体上,以构建的重组质粒为模板,用PCR方法合成了相应的地高辛标记的双链DNA探针。以合成的探针通过斑点杂交技术检测烟草病叶总RNA和烟草病叶汁液。TMV、CMV和PVY的3种地高辛探针检测各自感染的烟草病叶总RNA的稀释低限分别为1:1000、1:10000、1:320,检测各自侵染烟草病汁液的最大稀释倍数分别为1:100、1:100、1:10,而每种探针与健康烟草和其它2种病毒的反应均为阴性。     

High prevalence of viruses in table grape from Spain detected by real-time RT-PCR

Table grapes from one of the most important growing area in Spain (Vinalopó, Alicante) protected by the Designation of Origin “Vinalopó bagged table grape”, were surveyed and analysed to determine the prevalence of the five viruses included in the Spanish certification program: Arabis mosaic virus (ArMV), Grapevine fanleaf virus (GFLV), Grapevine fleck virus (GFkV), Grapevine leafroll associated virus-1 (GLRaV-1) and Grapevine leafroll associated virus-3 (GLRaV-3). Ninety five sampling points were selected and the position of grapevine plants georeferenced. Samples were collected in two different vegetative periods and analyses were performed by ELISA and real-time RT-PCR. Purified RNA and immobilized viral targets from plant extracts on nylon membranes were used in parallel assays as templates for PCR assays. In order to analyse these five viral species by real-time RT-PCR, new specific primers and TaqMan probes were designed for detection of ArMV and GFkV. Real time RT-PCR from purified RNA was more sensitive than spot version and ELISA tests. The most prevalent virus was GFLV (95.8%) followed by GLRaV-3 (94.7%), GLRaV-1 (66.3%) and GFkV (65.3%). ArMV was not detected in any sample. The high level of viral infections and the presence of mixed infections suggest that initial infected plant material and uncontrolled traffic of propagation material have played an important role in the spread of viruses.