香石竹斑驳病毒(CarMV)云南分离物CP基因的克隆和序列分析

 香石竹斑驳病毒(CarMV)是侵染香石竹的主要病毒。关于该病毒的株系和不同地区分离物的病毒核酸序列研究报道较少。     

香石竹斑驳病毒( CarMV) 主要基因的分子变异分析

 香石竹斑驳病毒(Carnation mottle virus, CarMV)是侵染香石竹的主要病毒之一。本试验从12 个香石竹品种中获得CarMV 分离物,通过RT-PCR 扩增包含p7、p9、CP 3 个主要基因的片段,并对扩增产物进行克隆测序。通过序列比对发现CarMV 的p7、p9、CP 3 个基因有较高的稳定性,p7 基因核苷酸序列相似性为98. 10% ,氨基酸序列相似性为97. 81% ,其中氨基酸的第11 和14 位存在显著差异;p9 基因核苷酸序列的相似性为98. 80% ,氨基酸序列相似性为99. 13% ,氨基酸序列在第4 差异明显;CP 基因核酸序列相似性为97. 58% ,氨基酸的相似性为98. 43% ,氨基酸序列的第164 和331 位的变异存在相关性,整个CP 变异位点比较分散。证实p7 和p9 的变异位点主要集中在暴露与寄主互作相关的N 端,推测这是导致病毒变异,与寄主互作变异的重要位点。     

香石竹斑驳病毒云南分离物全基因组序列测定和侵染性克隆构建

香石竹斑驳病毒(Carnation mottle virus,CarMV)是危害香石竹的一种重要病毒,本研究通过构建农杆菌介导的CarMV侵染性克隆来进一步研究该病毒基因功能。首先获得CarMV云南分离物全长序列,与报道的上海分离物相似性达到94.78%;将CarMV全长cDNA基因序列构建到具有35S启动子的双元表达载体pCV-nGFP,通过农杆菌浸润到本氏烟中瞬时表达,本氏烟系统叶片RT-PCR能检测到CarMV。试验结果表明,本研究构建Car-MV侵染性克隆通过农杆菌介导可快速高效侵染植物,可以用于病毒基因功能研究;同时CarMV云南分离物全长序列测定结果表明其属于P164 K331组群。     

香石竹斑驳病毒单克隆抗体的制备及检测应用

 用香石竹斑驳病毒(CarMV)免疫的BALB/c鼠脾细胞与Sp2/0鼠骨髓瘤细胞融合,经筛选克隆,获得5株能稳定传代且分泌抗CarMV单克隆抗体(MAb)的杂交瘤细胞,并分别制备它们的单克隆抗体腹水。5株单克隆抗体腹水间接ELISA效价达10^-6,其中3G1、1B9、2A9和2F8的抗体类型及亚类均为IgG1,而2F₂为IgG3。Western-blot分析表明,5株单克隆抗体均与CarMV 38 kD的外壳蛋白亚基有特异性反应。利用2A9单抗建立的抗原包被的间接ELISA (ACP-ELISA)检测CarMV方法,病叶1:800倍稀释、提纯CarMV病毒浓度为1 ng/mL (绝对检测量为0.1 ng)时仍能检测到病毒。利用ACP-ELISA对田间香石竹样品的检测表明,CarMV在香石竹上发病很普遍。     

侵染葫芦的黄瓜绿斑驳花叶病毒广西分离物分子鉴定

从广西南宁市郊温室大棚中的葫芦[Lagenaria siceraria(Molina)Stand.]上采集到一个表现脉绿、花叶症状的病毒样品,ELISA检测表明,该样品与黄瓜绿斑驳花叶病毒(Cucumber green mottle mosaic virus,CGMMV)有密切的血清学关系,利用RT-PCR方法从样品中扩增获得约500bp的DNA片段,序列分析表明,该片段是CGMMV的外壳蛋白基因,暂将该病毒分离物定名为GX-BG。外壳蛋白基因核苷酸序列系统进化树分析表明,已报道的CGMMV主要分为3大群体,GX-BG与中国辽宁分离物(CGMMV-LN)分别属于不同的群体。     

应用特异引物和简并引物检测百合斑驳病毒

应用特异引物和简并引物对百合斑驳病毒(LMoV)进行RT-PCR检测.结果表明,特异引物和简并引物均能从LMoV感病百合组织中扩增出与预期大小一致的目标片段,而健康组织无此扩增产物,简并引物还能从感染TBV的郁金香病叶中扩增出目标片段.将感染LMoV组织总RNA以10倍梯度稀释成不同浓度检测,特异引物检测的灵敏度为10-4,简并引物的灵敏度为10-3.对特异引物的PCR产物进行克隆和测序,序列分析表明与LMoV不同分离物的序列同源性为90%～99%,说明采用本研究确定的方法检测百合斑驳病毒结果准确可靠.     

烟草花叶病毒丁香分离物的分离与鉴定

 从表现花叶症状的丁香病株上获得一病毒分离物,其在电镜下为约300 nm×18nm的杆状粒子;电泳分析表明感病组织中ds RNA大约为6.4kbp,而其外壳蛋白分子量约为17.6k Da。以上实验结果初步将该病毒分离物鉴定为烟草花叶病毒属(Tobamovirus)。根据该属病毒复制酶基因序列设计通用引物,进行RT-PCR检测,扩增出约1000 bp的预期特异片段(Gen Bank AY566703)。将PCR产物克隆后测序,序列分析表明,与从蚕豆中分离的TMV-B株系序列(Gen Bank AJ011933.1)同源性为99.90%。根据烟草花叶病毒(Tobacco mosaic virus,TMV)的RNA CP基因序列设计引物,进行RT-PCR,扩增出约800 bp的预期特异片段(Gen Bank AY56672),序列分析表明,与TMV-B株系序列(Gen Bank AJ011933.1)同源性达99%,上述实验结果表明,该病毒分离物为TMV。由于该分离物与TMV-B在指示植物上的症状存在明显差异,所以,作者把该分离物暂命名为TMV-S。     

侵染扶桑的烟草花叶病毒分离物鉴定

从表现叶斑驳症状的扶桑病株上获得一病毒分离物,电镜下可见约300 nm×18 nm的杆状粒子,其与烟草花叶病毒抗血清呈明显的阳性反应,dsRNA约为6.4 kbp。根据烟草花叶病毒(tobacco.mosaic virus,TMV)的RNA序列设计引物,进行RT-PCR检测,扩增出约800 bp的预期特异片段。将PCR产物连接pMD18-T载体,转化大肠杆菌DH5α,得到了含有目的片段的重组子。序列分析表明,与周雪平等报道的序列(GenBank AJ011933.1)同源性达99％。通过生物学、病毒粒子观察、血清学以及分子生物学实验结果,确定该病毒分离物为TMV。     

应用斑点免疫法检测香石竹斑驳病毒

本文应用斑点免疫法(dotimmunobinding,简称DIB)检测了进口香石竹幼苗中的香石竹斑驳病毒。其中1990年从日本引进的材料检测了10个品种,全部呈阳性反应;1991年从荷兰引进材料检测的10个品种中有4个品种表现阴性反应,6个品种表现阳性反应。DIB检测结果与电镜观察结果高度一致,即DIB检测为阳性的材料在电镜下都可观测到病毒粒体,而DIB阴性反应的样品在电镜下检测不到粒体的存在。     

北京怀桑地区李矮缩病毒的检测鉴定

在北京怀柔地区核果类果树病毒疫情调查中,对樱桃树上有矮缩、斑驳、皱缩等症状的叶片样品,通过酶联免疫检测为阳性反应,进行RT-PCR鉴定、外壳蛋白基因扩增片段测序,发现该序列与李属坏死环斑病毒(PDV)ch株系分离物(L28145.1)序列的同源性为100%,与分离物(AF208746.1,AF208747.1,AF208743.1)序列的同源性大干97%,说明被检测样品感染有PDV.这是PDV病毒在北京地区发生的首次报道,对该病毒来源及其流行趋势也进行了分析.     

ELISA indexing of commercial carnations for carnation mottle virus using a urease-antibody conjugate

The high sensitivity of the urease form of enzyme-linked immunosorbent assay (ELISA) system allowed the use of pooled samples for the detection of carnation mottle virus (CarMV) with greater sensitivity than the phosphatase system. The urease-ELISA was used for a field assessment of the effectiveness of a Plant Improvement Programme (PIP) for carnations operated by the Victorian Department of Agriculture for the control of carnation mottle virus. On properties growing only PIP carnations, infection with CarMV averaged 0.95%. whereas cm properties growing carnations from ordinary commercial sources, all plants sampled contained the virus. The Plant Improvement Programme provided effective control of CarMV in Sim carnations.     

Non-radioactive molecular hybridization detection of carnation mottle virus in infected carnations and its comparison to serological and biological techniques

A non-radioactive molecular hybridization method was developed to detect carnation mottle virus (CarMV) in carnation plants. This method was compared to the standard ELISA test and biological assays. For crude plant extracts, the molecular hybridization technique proved to be at least 125 times more sensitive than double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The method was adapted to avoid the necessity to clarify the samples by centrifugation and to use pipettes to load them. By introducing this modification, the hybridization assay was found to be a suitable method for routine virus detection. The relative benefits of using this procedure for large-scale indexing are discussed.     

First report of Alternaria dianthicola causing flower blight on carnation in China

A severe disease of carnation flowers was observed in Kunming, China in November 2009. Initial symptoms on flowers and immature flower buds were characterized by water‐soaked areas. Spots with purple margins could be seen on petals of some varieties. An Alternaria sp. was isolated from 100% of symptomatic tissues sampled. The isolates showed high virulence when inoculated onto tissue culture plantlets and on healthy carnation flowers. Results of sequence analysis of 5.8S rDNA‐ITS of isolates showed 99% sequence similarity with Alternaria dianthicola in GenBank. To the best of the authors' knowledge, this was the first sighting of blight of flowers and immature flower buds of carnation caused by Alternaria dianthicola in China.     

Description of symptoms and assessment of loss caused by some viruses in the carnation cultivar ‘william sim’

A study was made of the influence of carnation mottle, ring spot and vein mottle viruses on carnations of the ‘William Sim’ variety by artificial infection of virus-free plants of one single clone. No clear leaf symptoms were obtained by artificial infection with the mottle virus, but leaf symptoms appeared on plants infected with the ring spot virus and the growth of these plants was markedly reduced. The carnation vein mottle virus caused a definite leaf flecking. A depressing effect on yield was demonstrated with all three viruses. Vein mottle was serious, particularly because it caused flower colour breaking. The ring spot virus, also, had a depressing effect on the quality of the flowers, causing a high percentage of split calices. The carnation mottle virus also caused a reduction in the quality of the produce, though not so intense as that caused by the ring spot virus. A combination of the two last-mentioned viruses proved slightly more serious than the ring spot virus alone.     

昆明地区香石竹斑驳病毒的鉴定、提纯及抗血清制备

在昆明地区栽培的香石竹上发现了香石竹斑驳病毒,人工接种可局部侵染苋色藜、墙生藜、千日红及番杏,可系统侵染昆诺阿藜和美国石竹,分别造成褪绿斑、斑驳或坏死斑。经二轮ＰＥＧ（分子量６０００）沉淀,病毒提纯量约２２０ｍｇ／ｋｇ鲜组织。电镜观察病毒颗粒直径为２８ｎｍ,等轴对称。提纯物紫外扫描呈典型病毒核蛋白吸收峰,Ａ２６０／Ａ２８０值为１．５６。提纯病毒经４次免疫家兔,所得抗血清经试管沉淀测定效价为１∶４０９６,琼脂糖双扩散效价为１∶１０２４。     

Biological and molecular characterization of a novel carmovirus isolated from angelonia

ABSTRACT A new carmovirus was isolated from Angelonia plants (Angelonia angustifolia), with flower break and mild foliar symptoms, grown in the United States and Israel. The virus, for which the name Angelonia flower break virus (AnFBV) is proposed, has isometric particles, approximately 30 nm in diameter. The experimental host range was limited to Nicotiana species, Schizanthus pinnatus, Myosotis sylvatica, Phlox drummondii, and Digitalis purpurea. Virions were isolated from systemically infected N. benthamiana leaves, and directly from naturally infected Angelonia leaves, using typical carmovirus protocols. Koch's postulates were completed by mechanical inoculation of uninfected Angelonia seedlings with purified virions. Isometric particles were observed in leaf dips and virion preparations from both Angelonia and N. benthamiana, and in thin sections of Angelonia flower tissue by electron microscopy. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of dissociated purified virus preparations, a major protein component with a molecular mass of 38 kDa was observed. Virion preparations were used to produce virus-specific polyclonal antisera in both Israel and the United States. The antisera did not react with Pelargonium flower break virus (PFBV), Carnation mottle virus (CarMV), or Saguaro cactus virus (SgCV) by either enzyme-linked immunosorbent assay or immunoblotting. In reciprocal tests, antisera against PFBV, CarMV, and SgCV reacted only with the homologous viruses. The complete nucleotide sequence of a Florida isolate of AnFBV and the coat protein (CP) gene sequences of Israeli and Maryland isolates were determined. The genomic RNA is 3,964 nucleotides and contains four open reading frames arranged in a manner typical of carmoviruses. The AnFBV CP is most closely related to PFBV, whereas the AnFBV replicase is most closely related to PFBV, CarMV, and SgCV. Particle morphology, serological properties, genome organization, and phylogenetic analysis are all consistent with assignment of AnFBV to the genus Carmovirus.     

黄瓜花叶病毒NASBA检测技术的建立

 以香蕉花叶病病样为材料,初步建立了黄瓜花叶病毒核酸序列依赖性扩增(Nucleic acid sequence based amplifica-tion,NASBA)的检测技术。通过以香蕉叶片总RNA为模板,在黄瓜花叶病毒(Cucumber mosaic virus,CMV)亚组ⅠRNA 2高保守区设计特异引物,进行NASBA反应,经5%琼脂糖凝胶电泳检测,阳性样品中出现了预期大小为310 bp的条带,而阴性和空白对照中均未出现。并对11份香蕉样品分别进行NASBA反应,并经过斑点杂交验证与RT-PCR检测比较,两者的检测结果一致,灵敏度相当,检出限量可达100 pg。