Pospieszny H, Hasiów B, Borodynko N
Department of Virology and Bacteriology, Institute of Plant Protection, Miczurina 20, 60-318 Poznan, Poland.
Plant Dis. 2007 May;91(5):639. doi: 10.1094/PDIS-91-5-0639B.
Zucchini yellow mosaic virus (ZYMV) is a member of the Potyvirus genus in the Potyviridae family, the largest group of plant viruses. Different isolates of this virus have been found in infected cucurbits throughout the world, including localities in Europe, America, Australia, and Asia. In August 2005, mosaic and yellowing of leaves, as well as yellow spots on green fruits, were observed on zucchini (Cucurbita pepo cv. giromontiina) growing in commercial fields in the Kujawsko-Pomorskie Region of Poland. Flexuous virus particles (~750 nm long), typical of potyviruses, were observed in leaf-dip preparations from symptomatic zucchini plants. The virus in the sap from symptomatic plants was mechanically transmitted and systemic infections were produced on Citrullus lanatus, Cucumis melo, Cucumis sativus, C. pepo cvs. giromontiina and patissoniana, C. maxima, and Nicotiana benthamiana. Severe symptoms such as severe malformation of leaves and stunting of plants were observed on zucchini plants (cv. giromontiina) infected mechanically with the virus and grown in the greenhouse. Double-antibody sandwich (DAS)-ELISA using an anti-ZYMV polyclonal antiserum (AS-0234; DSMZ, Braunschweig, Germany) identified the presence of ZYMV in mechanically infected C. pepo cv. giromontiina and N. benthamiana plants. Subsequently, a reverse transcription (RT)-PCR using a universal primer, Sprimer, designed from the consensus sequences that code for the conserved sequence GNNSGQP in the NIb region of Potyviridae family members and the M4 primer was performed (1). The 1740-bp PCR fragments were cloned into the pGEM-T vector (Promega, Madison, WI) and three randomly selected clones were sequenced on an ABI automatic sequencer. An 837-bp sequence representing the full length coat protein gene (GenBank Accession No. EF178505) was compared with homologous sequences from other ZYMV isolates using BioEdit and Mega 3.1 softwares. Genetic distances were calculated by Kimura's two-parameter method (2). Surprisingly, the Polish ZYMV isolate (ZYMV-Zug) was more closely related to ZYMV isolates from Asia than those from Europe. Pairwise comparisons of ZYMV-Zug with several other European ZYMV isolates (GenBank Accession Nos. DQ645729, AJ420020, AJ459956, AJ420014, AJ420019, DQ124239, and AJ420018) indicated an 81 to 82% nucleotide and 91 to 92% amino acid identity, while there was a 94% nucleotide and 99% amino acid identity with the Shanxi (GenBank Accession No. AY074808) and Shandong isolates (GenBank Accession No. AF513552) from China. References: (1) J. Chen et al. Arch. Virol. 146:757, 2001. (2) S. Kumar et al. Brie. Bioinform. 5:150, 2004.
西葫芦黄花叶病毒（ZYMV）是马铃薯Y病毒科马铃薯Y病毒属的成员，马铃薯Y病毒科是最大的植物病毒类群。在世界各地受感染的葫芦科植物中都发现了该病毒的不同分离株，包括欧洲、美洲、澳大利亚和亚洲的一些地区。2005年8月，在波兰库亚维-波美拉尼亚地区的商业种植田中，种植的西葫芦（Cucurbita pepo cv. giromontiina）出现了叶片花叶和黄化现象，以及绿色果实上出现黄斑。在有症状的西葫芦植株的叶浸液制剂中观察到了典型的马铃薯Y病毒的弯曲病毒粒子（约750纳米长）。有症状植株汁液中的病毒通过机械接种进行传播，并在西瓜、甜瓜、黄瓜、西葫芦品种giromontiina和patissoniana、南瓜以及本氏烟草上产生了系统感染。在用感染病毒的西葫芦（品种giromontiina）在温室中种植时，观察到了严重的症状，如叶片严重畸形和植株矮化。使用抗ZYMV多克隆抗血清（AS - 0234；德国不伦瑞克的德国微生物和细胞培养物保藏中心）进行的双抗体夹心（DAS）-ELISA检测，确定在机械接种感染的西葫芦品种giromontiina和本氏烟草植株中存在ZYMV。随后，使用根据马铃薯Y病毒科成员NIb区域中编码保守序列GNNSGQP的共有序列设计的通用引物Sprimer和M4引物进行了逆转录（RT）-PCR（1）。将1740碱基对的PCR片段克隆到pGEM - T载体（美国威斯康星州麦迪逊市的Promega公司）中，并在ABI自动测序仪上对三个随机选择的克隆进行测序。使用BioEdit和Mega 3.1软件，将代表全长外壳蛋白基因的837碱基对序列（GenBank登录号EF178505）与其他ZYMV分离株的同源序列进行比较。通过Kimura双参数法计算遗传距离（2）。令人惊讶的是，波兰的ZYMV分离株（ZYMV - Zug）与来自亚洲的ZYMV分离株的亲缘关系比与来自欧洲的ZYMV分离株更近。将ZYMV - Zug与其他几个欧洲ZYMV分离株（GenBank登录号DQ645729、AJ420020、AJ459956、AJ420014、AJ420019、DQ124239和AJ420018）进行成对比较，结果显示核苷酸同一性为81%至82%，氨基酸同一性为91%至92%，而与来自中国山西（GenBank登录号AY074808）和山东的分离株（GenBank登录号AF513552）的核苷酸同一性为94%，氨基酸同一性为99%。参考文献：（1）J. Chen等人，《病毒学档案》146:757，2001年。（2）S. Kumar等人，《Brief. Bioinform.》5:150，2004年。
