First Report of a Strain of Alternanthera yellow vein virus Infecting Eclipta prostrate (L.) L. (Compositae) in China

In 2005, Eclipta prostrata plants exhibiting yellow vein symptoms were observed in Guangzhou, Guangdong province, China. A virus isolate G8 was cloned from a symptomatic plant. The complete nucleotide sequence of G8 DNA-A was determined to be 2745 nucleotides, which had typical characteristics of Begomovirus genome organization. The comparison of complete nucleotide sequence of DNA-A showed that isolate G8 shared the highest sequence identity with Alternanthera yellow vein virus (AlYVV) isolates G38 and Hn51 at 95.9% and 94.3%, respectively. These results show that G8 infecting E. prostrata in Guangdong is a strain of AlYVV.     

Identification and Molecular Characterization of a New Geminivirus Betasatellite Infecting Malvastrum coromandelianum in China

The complete nucleotide sequence of a satellite molecule associated with Malvastrum leaf curl Guangdong virus (MLCuGdV) infecting M. coromandelianum plants exhibiting leaf curl symptoms in a suburb of Guangzhou, Guangdong Province of China, is described and analysed. The molecule has typical features of betasatellites, containing a single ORF in the complementary‐sense strand, an A‐rich region, the satellite‐conserved region and a stem–loop structure. Compared with the geminivirus betasatellites in GenBank database, this molecule shows the highest nucleotide sequence identity of 71.9% with Tomato leaf curl Philippine betasatellite isolate Laguna1 (ToLCPB, AB307732). Phylogenetic analysis indicates that it is more related to isolate Laguna 1 and Laguna 2 of ToLCPB. According to the proposed species demarcation threshold of betasatellites (78% nucleotide identity), it is a novel betasatellite species, for which we propose the name Malvastrum leaf curl Guangdong betasatellite (MLCuGdB).     

Papaya Leaf Curl Guangdong Virus and Ageratum Yellow Vein Virus Associated with Leaf Curl Disease of Tobacco in China

Two samples (YC7, YC27) of Nicotiana tabacum showing leaf curling, vein swelling and enations on undersides of leaves were collected in the Fujian Province of China in 2007. Virus isolates YC7‐1 and YC7‐2 (associated with betasatellite, YC7‐2β) were detected in both samples. The complete DNA‐A sequence of YC7‐1 (FJ869907) comprised 2741 nucleotides (nt). The complete DNA‐A (FJ869908) and betasatellite (FJ869909) sequence of YC7‐2 consisted of 2754 and 1344 nt, respectively. YC7‐1 had the highest nucleotide sequence identity (97.3%) with Papaya leaf curl Guangdong virus (PaLCuGuV‐[CN:Gd2:02], AJ558122). YC7‐2 had the highest sequence identity (90.1%) with Ageratum yellow vein virus (AYVV‐TW[TW:Tai:99], AF307861) and its betasatellite (96.5%) with Ageratum yellow vein betasatellite (AYVB‐[TW:CHu:02], AJ542495). These indicate that YC7‐1 and YC7‐2 are isolates of PaLCuGuV and AYVV, respectively. Symptoms including leaf curling, vein swelling and enations on undersides of leaves were observed in N. tabacum and N. glutinosa when infected by whiteflies with sample YC7 as the viral source under greenhouse conditions. PCR results showed that these infected plants contained both YC7‐1 and YC7‐2/YC7‐2β. To our knowledge, this is the first report of PaLCuGuV and AYVV/AYVB co‐infecting N. tabacum in China.     

Molecular variation of satellite DNA beta molecules associated with Malvastrum yellow vein virus and their role in pathogenicity

Previous studies have found that the diversity of begomovirus-associated DNA beta satellites is related to host and geographical origin. In this study, we have cloned and sequenced 20 different isolates of DNA beta molecules associated with Malvastrum yellow vein virus (MYVV) isolated from Malvastrum coromandelianum plants in different geographical locations of Yunnan Province, China. Analyses of their molecular variation indicate that the satellites are clustered together according to their geographical location but that they have only limited sequence diversity. Infectivity tests using infectious clones of MYVV and its associated DNA beta molecule indicate that MYVV DNA beta is indispensable for symptom induction in Nicotiana benthamiana, N. glutinosa, Petunia hybrida, and M. coromandelianum plants. Furthermore, we showed that MYVV interacts functionally with heterologous DNA beta molecules in N. benthamiana plants.     

Short Communication: Ageratum,Croton and Malvastrum harbour geminiviruses: evidence through PCR amplification

Ageratum conyzoides, Croton bonpladianum and Malvastrum coromandelianum are common weeds found around agricultural fields. In several cases these were found to exhibit vein yellowing and yellow mosaic symptoms. Using degenerate primers specific for whitefly-transmitted geminiviruses (WTGs), and total DNA isolated from such infected plants (exhibiting the above symptoms) as a template, 1.2kbp fragments were amplified and were shown to have homology to DNA-A of Indian tomato leaf curl virus (ITLCV) by Southern hybridization. In control experiments the same primers failed to amplify any DNA fragments from the total DNA isolated from healthy plants (no symptoms as above). These results show that Ageratum, Croton and Malvastrum harbour geminivirus(es).     

广东番茄曲叶病毒G2分离物基因组DNA-A的分子特征

从采集于广东的番茄曲叶病病株上分离到病毒分离物G2 ,序列分析结果表明 ,其DNA_A为单链环状 ,全长2 74 4nt,共有 6个ORF ,其中病毒链上编码AV1(CP)、AV2 ,互补链上编码AC1、AC2、AC3和AC4。BLAST结果显示 ,与G2基因组有同源关系的病毒均属双生病毒科菜豆金色花叶病毒属。序列比较结果显示 ,G2与菜豆金色花叶病毒属病毒的DNA_A序列同源率均不超过 83% ,其中同源率最高的是PaLCuCNV_[G10 ](82 8% )。进一步比较发现 ,它们的基因间隔区 (IR)变异最大 (同源率为 30 9%～ 81 8% ) ;CP氨基酸序列的同源率较高 (77 6 %～ 99 2 % ) ,AC4蛋白氨基酸序列的同源率较低 (4 3 5 %～ 78 8% )。系统进化关系分析结果也显示 ,G2与已报道的菜豆金色花叶病毒属病毒的亲缘关系均较远。因此 ,G2可能是双生病毒科菜豆金色花叶病毒属中一个未报道的新种 ,命名为广东番茄曲叶病毒 (TomatoleafcurlGuangdongVirus ,ToLCGDV)     

侵染广西烟草的中国番茄黄化曲叶病毒及其伴随的卫星DNA分子的基因组特征

从中国广西靖西的烟草病株上分离到病毒分离物G102和G103,用双生病毒特异性引物均扩增出约500bp的片段,两者序列同源性达99%。对G102基因组DNA-A全序列测定表明,其全长为2728个核苷酸,与中国番茄黄化曲叶病毒(TYLCCNV)同源性最高,达96.5%。进一步研究发现,G102和G103都伴随有长为1342个核苷酸的卫星DNA分子(DNAβ),这两个DNAβ分子的全序列与TYLCCNV的DNAβ同源性最高,分别为92.9%和93.4%。这是首次明确广西分离的TYLCCNV也伴随有卫星分子。     

Characterization and Complete Nucleotide Sequence of Two Isolates of Tomato mosaic virus

Two virus isolates, designated S1 and TL, were obtained from tomato and camellia root in China, respectively, and their host ranges, symptomatology, serological reactions and complete nucleotide sequences were determined. Isolate TL systemically infected Chenopodium amaranticolor causing leaf chlorosis, but the isolate S1 induced only local necrotic lesions. The complete nucleotide sequences of S1 and TL were determined and consisted of 6384 and 6383 nucleotides (Genbank accessions AJ132845 and AJ417701 ), respectively. Sequence analysis revealed that both isolates have the highest nucleotide sequence identity (over 92%) with Tomato mosaic virus (ToMV), but less (80%) with other tobamoviruses. Phylogenetic analyses based on the amino acid sequences of 30‐kD and 17.5‐kD proteins also indicated that both the isolates form a cluster with the isolates of ToMV. These data suggest that S1 and TL are isolates of ToMV. The possible reasons that TL infected C. amaranticolor systemically but S1 induced only local necrotic lesions are discussed.     

我国肾综合征出血热疫苗生产株LR1株的全基因组序列分析

为测定我国肾综合征出血热疫苗生产株LR1株的全基因组序列 ,了解该株分子基础 ,从提取的细胞总RNA逆转录PCR扩增 ,产物纯化后克隆T载体纯化后测序 ,结果证明 ,LR1株全基因组序列由L6 5 33、M36 16、S片段的16 92个核苷酸组成 ,依各自读码框架分别编码 2 15 1、1135、42 9个氨基酸。序列同源比较分析表明 ,LR1毒株与国外HTN型毒株高度同源 ,属同一亚型 ,尤其与HTN代表株 76 - 1183个片段同源率高达 99 3%～ 99 8% ,而与国内的HTN型病毒差异较大 ,同源率仅为 79 4%～ 84 6 %。氨基酸比较也显示了同样的结果。     

Complete Genome Sequences of Two Chinese Beet soil-borne virus Isolates Provide Evidence that the Genome is Highly Conserved

The complete nucleotide sequences of two Chinese isolates of Beet soil-borne virus (BSBV) from the Inner Mongolia and Xinjiang provinces (designated BSBV-IM and BSBV-XJ, respectively) were found to share around 99% sequence identity with that of a previously reported German isolate (BSBV-G). The genome organization of the three isolates was identical. A diversity index (Pi) analysis indicated that the overall nucleotide variability of all RNAs among the three isolates was <7%, only for the 5' part of the first triple gene block gene on RNA3 was it >6%. Although the 3' end of BSBV RNA 3 was previously reported to be highly variable, the results of this study show that the total BSBV genomes are considerably conserved, especially RNAs 1 and 2.     

香蕉束顶病毒基因克隆和序列分析

对香蕉束顶病毒（ＢＢＴＶ）中国分离株ＤＮＡ组份Ｉ（ＤＮＡ－１）、外壳蛋白（ＣＰ）和运转蛋白（ＭＰ）基因进行了克隆和序列分析。ＢＢＴＶＤＮＡ－１含有１１０３个核苷酸,与南太平洋和亚洲分离株分别有８７％－８８％ ９６．９－９８％的核苷酸序列同源性。由ＤＮＡ－１编码的复制酶含有１８６个在酸残基。与南太平洋和亚洲分离株分别有８４．４％－９５．８％和９７．６％、９８．０％的氨基酸序列同源性。外壳蛋白基因由５     

Cloning and sequencing of partial DNA-A of Cassava mosaic virus

Abstract

Polymerase chain reaction of Cassava mosaic virus revealed that out of the 50 samples analysed only two samples, one from Musiri (Trichy district) and other from Mallur (Salem district), were detected with ICMV infection as 904 bp fragment of DNA-A amplified. All the other samples from various districts of Tamil Nadu were detected invariably with SLCMV as they amplified 599 bp of DNA-A. A 599 bp fragment of DAN-A was cloned and sequenced from the sample collected from Mallur. The nucleotide sequence has been submitted to GenBank under the accession number DQ303479. The nucleotide sequence was compared with other cassava infecting geminiviruses and other geminiviruses in GenBank. Cluster dendrogram revealed that the cloned sequence was most closely related to ICMV, Maharastra strain rather than SLCMV, forming one cluster. Comparative sequence analyses showed that the cloned fragment shared a maximum sequence identity with ICMV at nucleotide levels (93%) than with SLCMV (88%).     

Complete nucleotide sequence and the genome organization of tobacco leaf curl geminivirus from Japan

The genomic DNA of tobacco leaf curl geminivirus (TLCV) from tomato plants with leaf curl disease in Japan has been sequenced. The single circular DNA molecule comprises 2,761 nucleotides. TLCV DNA contains six open reading frames (ORFs) capable of encoding proteins with a molecular weight greater than 10 K. In total nucleotide sequence comparisons with other geminiviruses, TLCV was most closely related to tomato leaf curl virus from Taiwan (TwToLCV) (76% identity), tomato leaf curl virus from Bangalore (ToLCV-Ba) (74%) and agerantum yellow vein virus (AYVV) (74%), all possessing a monopartite genome. The significant but relatively low sequence similarity in the genomic DNA between TLCV and other geminiviruses suggests it is a distinct geminivirus in genus Begomovirus.     

Begomoviruses Associated with Leaf Curl Disease of Tomato in Java,Indonesia*

We report that several begomoviruses are associated with tomato leaf curl disease in Java, Indonesia. Tomato plants with leaf curl symptoms were collected from Bandung (west Java), Purwokerto (central Java), Magelang (central Java) and Malang (east Java) of Indonesia, the major tomato‐growing areas of the country. Viruses were detected using the polymerase chain reaction (PCR), with universal primers for the genus Begomovirus. PCR‐amplified fragments were cloned and sequenced. Based on sequence comparisons and phylogenetic analyses, the viruses were divided into three groups. With respect to amino acid (aa) identities of the N‐terminal halves of the coat proteins compared in this study, group I was most closely related to Ageratum yellow vein virus (AYVV) (97%), Ageratum yellow vein China virus‐[Hn2] (AYVCNV‐[Hn2]) (96%) and Ageratum yellow vein virus‐[Taiwan] (AYVV‐[Tai]) (95%), and ageratum‐infecting begomovirus from Java (99%). Group II had high sequence identity with a tentative species of tomato leaf curl Java virus (ToLCJAV) (96% aa) for the CP. Group III was most closely related to a proposed species of Pepper yellow leaf curl Indonesia virus (PepYLCIDV) (90% aa identity) by its partial CP sequence.     

Molecular characterizations of two begomoviruses infecting Vinca rosea and Raphanus sativus in India

Dear Editor Samples of Vinca rosea and Raphanus sativus leaves showing typical leaf curling were collected from gardens and fields of Bhatinda,Punjab (India).An expected product of ～550 bp in size was amplified from total DNA extracts of symptomatic leaf samples with universal primers on the coat protein region of begomoviral DNA-A component.Moreover,DNA β were also detected in both V.rosea and R.sativus using β satellite universal primers.This is the first report of a β satellite associated with V.rosea in India.The presence of begomoviruses was also confirmed by Southern blot analysis using cloned DNA-A probe of Papaya leaf curl virus.Sequence analysis of viruses infecting V.rosea (Vinca yellow vein virus) and R.sativus (Raphanus sativus leaf curl Bhatinda virus) showed 74％ and 84％ nucleotide sequence identity with Papaya leaf curl virus,respectively.     

侵染朱槿的木尔坦棉花曲叶病毒及其卫星DNA全基因组结构特征

从广州朱槿上分离到病毒分离物G6,全序列测定结果表明,G6 DNA-A全长为2 737个核苷酸.序列比较显示,G6 DNA-A与木尔坦棉花曲叶病毒(CLCuMV)各分离物的同源率均大于89%,其中与CLCuMV-[62]的同源率最高(96.1%),与拉贾斯坦棉花曲叶病毒(CLCuRV)的同源率87.1%～89.8%,而与其他菜豆金色花叶病毒属病毒同源率均在87%以下.DNA-A系统进化关系分析显示,G6与CLCuMV各分离物的亲缘关系最近,聚在一起形成一个分支,而与其他几种双生病毒的亲缘关系相对较远.利用DNAβ特异引物β01和β02,从G6中扩增到卫星DNA分子(DNAβ).序列分析结果表明,G6 DNAβ全长1 346个核苷酸,推导其互补链上编码一个ORF(C1).序列比较结果表明,G6 DNAβ与CLCuMV DNAβ的同源率最高(92.1%),与CLCuRV DNAβ的同源率为88.7%,而与其他已报道的DNAβ的同源率均在80%以下.DNAβ系统进化关系分析显示,G6 DNAβ与CLCuMV DNAβ形成一个独立的分支,再与CLCuRV及MYVV-[Y47]的DNAβ形成一个较大分支.从上述研究结果可以得出,侵染广东朱槿的病毒分离物G6应该是CLCuMV一个分离物.     

2001～2011年上海市风疹病毒分子流行病学研究

本研究对2001～2011年本实验室保存的血清标本检测结果为麻疹IgM阴性,风疹IgM阳性病例相对应的咽拭子标本进行风疹病毒（Rubella virus,RV）分离,用RT-PCR方法对细胞培养产物鉴定后扩增病毒E1基因,扩增产物用于核苷酸序列测定,并进行分子流行病学分析。结果表明,60份咽拭子标本共分离到31株RV,获得27株RV的739nt（nt8 731～nt9 469）核苷酸序列,系统同源性分析表明,27株RV分离株分别属于两个不同的基因型,除分离自2011年的11009株、11052株和11106株为2B基因型外,其他分离株均为1E基因型。27株RV分离株大部分的核苷酸突变为无义突变,氨基酸序列高度保守。24株1E基因型分离株中大部分毒株氨基酸序列完全一致,自2001年以来可能有来自同一传播链的RV在持续传播。本研究首次监测到2B基因型RV2011年开始在上海流行,经GenBank核苷酸序列比对发现,其与越南、日本、阿根廷等国家近几年的RV分离株核苷酸序列同源性达99%。由于以前对风疹的监测较少,尚不能证明其来源。     

Molecular Characterization of a Distinct Begomovirus and its Associated Satellite DNA Molecule Infecting Sida acuta in China*

Three viral isolates Hn8, Hn40 and Hn41 were obtained from Sida acuta showing yellow mosaic symptom in the Hainan province, China. Comparison of partial DNA‐A sequences amplified with degenerate primers confirmed the existence of single type of Begomovirus. The complete nucleotide sequence of the DNA‐A‐like molecule of Hn8 was determined to be 2749 nucleotides, having a typical genetic organization of a Begomovirus. Hn8 DNA‐A had the highest sequence identity (78%) with that of Ageratum yellow vein China virus‐[G13] ( AJ558120 ), and had less sequence identity with other begomoviruses. Based on the above molecular data, Hn8 was thus considered as a new Begomovirus species, for which the name Sida yellow mosaic China virus (SiYMCNV) is proposed. Satellite DNA‐β molecules (Hn8‐β, Hn40‐β and Hn41‐β) were found to be associated with Hn8, Hn40 and Hn41 and their complete nucleotide sequences were determined. Sequence analysis showed that Hn8‐β, Hn40‐β and Hn41‐β shared more than 84% nucleotide sequence identity, and they were different from other characterized DNA‐β, sharing the highest nucleotide sequence identity (47.8%) with DNA‐β of Ageratum yellow vein virus.     

猪繁殖与呼吸综合征病毒HB-1(sh)/2002株全基因组分子特征分析

猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus,PRRSV)可引起妊娠母猪流产,早产,产死胎、弱胎、木乃伊胎及仔猪和肥育猪的呼吸道症状.最先于20世纪80年代末期爆发于美国和欧洲一些国家,随后很快传至全世界,给世界养猪业造成了巨大的损失.我国在1995年底爆发该病,之后蔓延到我国很多省份.1996年郭宝清、杨汉春等分别从疑似PRRS的病例中分离出PRRSV[1,2].     

Characterization of Maize Chlorotic Mottle Virus Associated with Maize Lethal Necrosis Disease in China

A maize lethal necrosis disease was observed in Yunnan province of China. Isometric virus particles 30 nm in diameter were found in infected maize leaf tissues. Using DAS‐ELISA, diseased maize plant samples reacted positively with the antiserum of Maize chlorotic mottle virus (MCMV). The complete nucleotide sequence (4436 nt) of a Yunnan isolate of MCMV was determined; it shares 97% nucleotide sequence identity with previously reported MCMV isolates. This is the first report of MCMV occurring in China.