Sanfaçon Hélène, Wellink Joan, Le Gall Olivier, Karasev Alexander, van der Vlugt René, Wetzel Thierry
Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, P O Box 5000, 4200 Highway 97, Summerland, BC V0H-1Z0, Canada.
Arch Virol. 2009;154(5):899-907. doi: 10.1007/s00705-009-0367-z. Epub 2009 Apr 7.
The order Picornavirales includes several plant viruses that are currently classified into the families Comoviridae (genera Comovirus, Fabavirus and Nepovirus) and Sequiviridae (genera Sequivirus and Waikavirus) and into the unassigned genera Cheravirus and Sadwavirus. These viruses share properties in common with other picornavirales (particle structure, positive-strand RNA genome with a polyprotein expression strategy, a common replication block including type III helicase, a 3C-like cysteine proteinase and type I RNA-dependent RNA polymerase). However, they also share unique properties that distinguish them from other picornavirales. They infect plants and use specialized proteins or protein domains to move through their host. In phylogenetic analysis based on their replication proteins, these viruses form a separate distinct lineage within the picornavirales branch. To recognize these common properties at the taxonomic level, we propose to create a new family termed "Secoviridae" to include the genera Comovirus, Fabavirus, Nepovirus, Cheravirus, Sadwavirus, Sequivirus and Waikavirus. Two newly discovered plant viruses share common properties with members of the proposed family Secoviridae but have distinct specific genomic organizations. In phylogenetic reconstructions, they form a separate sub-branch within the Secoviridae lineage. We propose to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae.
小RNA病毒目包括几种植物病毒,目前被归类于豇豆花叶病毒科(包括豇豆花叶病毒属、蚕豆病毒属和线虫传多面体病毒属)和伴生病毒科(包括伴生病毒属和水稻矮缩病毒属)以及未归类的樱桃病毒属和沙德瓦病毒属。这些病毒与其他小RNA病毒目病毒具有共同特性(颗粒结构、具有多蛋白表达策略的正链RNA基因组、包括III型解旋酶、一种3C样半胱氨酸蛋白酶和I型RNA依赖的RNA聚合酶的共同复制模块)。然而,它们也具有一些独特特性,使其与其他小RNA病毒目病毒区分开来。它们感染植物,并利用特殊的蛋白质或蛋白质结构域在宿主中移动。在基于其复制蛋白的系统发育分析中,这些病毒在小RNA病毒目分支内形成一个单独的独特谱系。为了在分类学层面识别这些共同特性,我们提议创建一个新的科,称为“联体病毒科”,以包括豇豆花叶病毒属、蚕豆病毒属、线虫传多面体病毒属、樱桃病毒属、沙德瓦病毒属、伴生病毒属和水稻矮缩病毒属。两种新发现的植物病毒与提议的联体病毒科成员具有共同特性,但具有独特的特定基因组结构。在系统发育重建中,它们在联体病毒科谱系内形成一个单独的亚分支。我们提议创建一个新的属,称为番茄卷叶病毒属(模式种,番茄卷叶病毒),并将该属归入提议的联体病毒科。