Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-CIAP-INTA), Camino 60 Cuadras Km 5,5 (X5020ICA), Córdoba, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas, Unidad de Fitopatología y Modelización Agrícola, Córdoba, Argentina.
Arch Virol. 2023 Jun 20;168(7):184. doi: 10.1007/s00705-023-05813-7.
The family Flaviviridae is composed of viruses with a positive-sense single-stranded RNA genome and includes viruses that are important veterinary and human pathogens. Most members of the family are arthropod- and vertebrate-infecting viruses, but more recently, divergent flavi-like viruses have been identified in marine invertebrate and vertebrate hosts. The striking discovery of gentian Kobu-sho-associated virus (GKaV), along with a recent report of a related virus from carrot, has expanded the known host range of flavi-like viruses to plants, suggesting they could be grouped in a proposed genus tentatively named "Koshovirus". Here, we report the identification and characterization of two novel RNA viruses that show a genetic and evolutionary relationship to the previously identified "koshoviruses". Their genome sequences were obtained from transcriptomic datasets of the flowering plants Coptis teeta and Sonchus asper. These two new viruses, which we have named "coptis flavi-like virus 1" (CopFLV1) and "sonchus flavi-like virus 1" (SonFLV1), are members of novel species characterized by the longest monopartite RNA genome observed so far among plant-associated RNA viruses, which is ca. 24 kb in size. Structural and functional annotations of the polyproteins of all koshoviruses resulted in the detection not only of the expected helicase and RNA-dependent RNA polymerase but also of several additional divergent domains, including AlkB oxygenase, trypsin-like serine protease, methyltransferase, and envelope E1 flavi-like domains. Phylogenetic analysis showed that CopFLV1, SonFLV1, GKaV, and the carrot flavi-like virus were grouped together in a monophyletic clade, strongly supporting the recent proposal for creation of the genus "Koshovirus" for the group of related plant-infecting flavi-like viruses.
黄病毒科由具有正链单链 RNA 基因组的病毒组成，包括对兽医和人类重要的病原体。该科的大多数成员是感染节肢动物和脊椎动物的病毒，但最近在海洋无脊椎动物和脊椎动物宿主中发现了分化的黄病毒样病毒。与 Gentian Kobu-sho 相关病毒 (GKaV) 的惊人发现，以及最近从胡萝卜中报道的一种相关病毒，将黄病毒样病毒的已知宿主范围扩展到了植物，这表明它们可能被归为一个新提议的属，暂定名为“Koshovirus”。在这里，我们报告了两种新型 RNA 病毒的鉴定和特征，它们与先前鉴定的“koshoviruses”在遗传和进化上具有关系。它们的基因组序列是从开花植物黄连和苦荬菜的转录组数据集获得的。这两种新病毒，我们分别命名为“黄连黄病毒 1”(CopFLV1)和“苦荬菜黄病毒 1”(SonFLV1)，是新型种的成员，其单份 RNA 基因组是迄今在植物相关 RNA 病毒中观察到的最长的，大小约为 24kb。所有 Koshovirus 的多蛋白的结构和功能注释不仅检测到了预期的解旋酶和 RNA 依赖性 RNA 聚合酶，还检测到了几个额外的发散结构域，包括 AlkB 氧化酶、胰蛋白酶样丝氨酸蛋白酶、甲基转移酶和包膜 E1 黄病毒样结构域。系统发育分析表明，CopFLV1、SonFLV1、GKaV 和胡萝卜黄病毒样病毒聚集在一个单系分支中，强烈支持最近提出的为相关植物感染黄病毒样病毒创建“Koshovirus”属的建议。
