Departamento de Fitopatologia, Universidade de Brasília (UnB), Campus Universitário Darcy Ribeiro, Brasília DF 70910-900, Brazil.
Embrapa Hortaliças, Brasília DF 70275-970, Brazil.
Viruses. 2020 Aug 27;12(9):950. doi: 10.3390/v12090950.
In a systematic field survey for plant-infecting viruses, leaf tissues were collected from trees showing virus-like symptoms in Brazil. After viral enrichment, total RNA was extracted and sequenced using the MiSeq platform (Illumina). Two nearly full-length picorna-like genomes of 9534 and 8158 nucleotides were found associated with ( family). Based upon their genomic information, specific primers were synthetized and used in RT-PCR assays to identify plants hosting the viral sequences. The larger contig was tentatively named as -associated virus 1 (HDaV1), and it exhibited low nucleotide and amino acid identities with species. The smaller contig was related to insect-associated members of the family but exhibited a distinct genome organization with three non-overlapping open reading frames (ORFs), and it was tentatively named as -associated virus 2 (HDaV2). Phylogenetic analysis using the amino acid sequence of RNA-dependent RNA polymerase (RdRp) revealed that HDaV1 and HDaV2 clustered in distinct groups, and both viruses were tentatively assigned as new members of the order . HDaV2 was assigned as a novel species in the family. The 5' ends of both viruses are incomplete. In addition, a nucleotide composition analysis (NCA) revealed that HDaV1 and HDaV2 have similarities with invertebrate-infecting viruses, suggesting that the primary host(s) of these novel virus species remains to be discovered.
在一项针对植物感染病毒的系统实地调查中，从巴西表现出类似病毒症状的树木中采集了叶片组织。在进行病毒富集后，使用 MiSeq 平台（Illumina）提取并测序了总 RNA。发现与 （家族）相关的两个近全长的类似微小核糖核酸病毒的基因组分别为 9534 和 8158 个核苷酸。根据它们的基因组信息，合成了特异性引物，并用于 RT-PCR 检测以鉴定宿主植物携带的病毒序列。较大的序列被暂命名为 -associated virus 1（HDaV1），与 物种的核苷酸和氨基酸同一性较低。较小的序列与昆虫相关的 家族成员有关，但具有独特的基因组组织，有三个不重叠的开放阅读框（ORFs），被暂命名为 -associated virus 2（HDaV2）。使用 RNA 依赖性 RNA 聚合酶（RdRp）的氨基酸序列进行的系统发育分析表明，HDaV1 和 HDaV2 聚类在不同的组中，这两种病毒都被暂定为目 的新成员。HDaV2 被分配为 家族的一个新种。两种病毒的 5' 末端都不完整。此外，核苷酸组成分析（NCA）表明，HDaV1 和 HDaV2 与无脊椎动物感染的病毒具有相似性，这表明这些新病毒种的主要宿主仍有待发现。
