Yang Caixia, Zhang Song, Han Tong, Fu Jingjing, Di Serio Francesco, Cao Mengji
Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, College of Life Science and Engineering, Shenyang University, Shenyang, China.
National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Chongqing, China.
Front Microbiol. 2019 Jun 25;10:1417. doi: 10.3389/fmicb.2019.01417. eCollection 2019.
A previously unreported disease affecting jujube ( Mill.) trees was observed in China (Liaoning province) in 2015 and named jujube yellow mottle disease (JYMD), due to prevalent symptoms on the leaves. Diseased plants produced also malformed and discolored fruits. In an attempt to identify the possible causal agent of JYMD, high-throughput sequencing of small RNA libraries was performed and a novel virus, tentatively named jujube yellow mottle-associated virus (JYMaV), was identified and characterized. Six genomic RNA segments of JYMaV were completely sequenced. Each one contains a single open reading frame in the viral complementary strand and two untranslated regions with complementary 5' and 3' terminal ends, thus showing typical features of other negative-stranded RNA viruses. RNA1 (7.1 kb), RNA2 (2.2 kb) and RNA3 (1.2 kb) encode putative proteins that, based on their conserved motifs, have been identified as the RNA dependent RNA polymerase, the glycoprotein and the nucleocapsid protein, respectively. These proteins share significant sequence identity (52.1-70.4%) with proteins encoded by raspberry leaf blotch virus (RLBV). RNA4 (1.5 kb) and RNA5 (1.2 kb) code for two putative 30 K movement proteins also related to the homologous RLBV protein. The functional role of the protein encoded by JYMaV RNA6 remains unknown. These data together with the phylogenetic relationships of JYMaV with other recognized emaraviruses support the proposal that JYMaV is the representative member of a novel species in the genus . In agreement with this proposal, virus-like particles and double-membrane-bound bodies, similar to those previously reported for other emaraviruses, were observed by transmission electron microscopy in extracts and tissues from symptomatic leaves, respectively. A specific RT-PCR-based detection method has been developed and used in a preliminary field survey that provided results strongly supporting the close association of JYMaV with the novel disease.
2015年在中国辽宁省发现了一种此前未报道过的影响枣树（枣属）的病害，因其叶片上普遍出现的症状，将其命名为枣黄斑驳病（JYMD）。患病植株还会结出畸形和变色的果实。为了确定可能导致JYMD的病原体，对小RNA文库进行了高通量测序，并鉴定和表征了一种新型病毒，暂定名为枣黄斑驳相关病毒（JYMaV）。对JYMaV的6个基因组RNA片段进行了全序列测定。每个片段在病毒互补链中都包含一个单一的开放阅读框以及两个具有互补5'和3'末端的非翻译区，因此显示出其他负链RNA病毒的典型特征。RNA1（7.1 kb）、RNA2（2.2 kb）和RNA3（1.2 kb）编码的假定蛋白，根据其保守基序，分别被鉴定为RNA依赖RNA聚合酶、糖蛋白和核衣壳蛋白。这些蛋白与树莓叶斑点病毒（RLBV）编码的蛋白具有显著的序列同一性（52.1 - 70.4%）。RNA4（1.5 kb）和RNA5（1.2 kb）编码两种假定的30K运动蛋白，也与同源的RLBV蛋白相关。JYMaV RNA6编码的蛋白的功能作用尚不清楚。这些数据以及JYMaV与其他已确认的埃玛病毒的系统发育关系支持了JYMaV是该属一个新物种的代表成员的提议。与此提议一致的是，通过透射电子显微镜在有症状叶片的提取物和组织中分别观察到了类似于先前报道的其他埃玛病毒的病毒样颗粒和双膜结合体。已经开发了一种基于RT-PCR的特异性检测方法，并用于初步的田间调查，结果有力地支持了JYMaV与这种新病害的密切关联。
