Department of Plant Pathology, University of California-Davis, Davis, CA 95616, USA.
Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, 70126 Bari, Italy.
Viruses. 2019 Jul 26;11(8):685. doi: 10.3390/v11080685.
Two novel negative-stranded (ns)RNA viruses were identified by high throughput sequencing in grapevine. The genomes of both viruses, named grapevine Muscat rose virus (GMRV) and grapevine Garan dmak virus (GGDV), comprise three segments with each containing a unique gene. Based on sequence identity and presence of typical domains/motifs, the proteins encoded by the two viruses were predicted to be: RNA-dependent RNA polymerase (RdRp), nucleocapsid protein (NP), and putative movement protein (MP). These proteins showed the highest identities with orthologs in the recently discovered apple rubbery wood viruses 1 and 2, members of a tentative genus (Rubodvirus) within the family . The three segments of GMRV and GGDV share almost identical sequences at their 5' and 3' termini, which are also complementary to each other and may form a panhandle structure. Phylogenetics based on RdRp, NP and MP placed GMRV and GGDV in the same cluster with rubodviruses. Grapevine collections were screened for the presence of both novel viruses via RT-PCR, identifying infected plants. GMRV and GGDV were successfully graft-transmitted, thus, they are the first nsRNA viruses identified and transmitted in grapevine. Lastly, different evolutionary scenarios of nsRNA viruses are discussed.
通过高通量测序在葡萄中鉴定出两种新型负链（ns）RNA 病毒。这两种病毒的基因组，命名为葡萄麝香玫瑰病毒（GMRV）和葡萄 Gara ndmak 病毒（GGDV），由三个片段组成，每个片段都包含一个独特的基因。基于序列同一性和典型结构域/基序的存在，两种病毒编码的蛋白质被预测为：RNA 依赖性 RNA 聚合酶（RdRp）、核衣壳蛋白（NP）和推定的运动蛋白（MP）。这些蛋白质与最近发现的苹果橡胶木病毒 1 和 2 的同源物具有最高的同一性，苹果橡胶木病毒 1 和 2 是家族中的一个暂定属（Rubodvirus）的成员。GMRV 和 GGDV 的三个片段在其 5'和 3'末端具有几乎相同的序列，它们彼此互补，可能形成一个发夹结构。基于 RdRp、NP 和 MP 的系统发育将 GMRV 和 GGDV 置于与 rubodviruses 相同的聚类中。通过 RT-PCR 对葡萄属植物进行了两种新型病毒的检测，发现了感染植物。GMRV 和 GGDV 成功地通过嫁接进行了传播，因此，它们是在葡萄中首次鉴定和传播的 nsRNA 病毒。最后，讨论了 nsRNA 病毒的不同进化情景。
