TL;DR: This work proposes to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae, a new family of plant viruses that infect plants and use specialized proteins or protein domains to move through their host.
Abstract: 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.
TL;DR: This is the first attempt to integrate viral data within the new B. tabaci species complex framework and it is clear that matching historical transmission data with the current species framework is difficult due to the lack of awareness of the underlying genetic diversity within B.tabaci.
TL;DR: A new virus isolated from tomato plants from the Murcia region in Spain which showed symptoms of ‘torrado disease’ very distinct necrotic, almost burn-like symptoms on leaves of infected plants most likely represents a member of a new plant virus genus.
Abstract: A new virus was isolated from tomato plants from the Murcia region in Spain which showed symptoms of ‘torrado disease’ very distinct necrotic, almost burn-like symptoms on leaves of infected plants. The virus particles are isometric with a diameter of approximately 28 nm. The viral genome consists of two (+)ssRNA molecules of 7793 (RNA1) and 5389 nts (RNA2). RNA1 contains one open reading frame (ORF) encoding a predicted polyprotein of 241 kDa that shows conserved regions with motifs typical for a protease-cofactor, a helicase, a protease and an RNA-dependent RNA polymerase. RNA2 contains two, partially overlapping ORFs potentially encoding proteins of 20 and 134 kDa. These viral RNAs are encapsidated by three proteins with estimated sizes of 35, 26 and 23 kDa. Direct protein sequencing mapped these coat proteins to ORF2 on RNA2. Phylogenetic analyses of nucleotide and derived amino acid sequences showed that the virus is related to but distinct from viruses belonging to the genera Sequivirus, Sadwavirus and Cheravirus. This new virus, for which the name tomato torrado virus is proposed, most likely represents a member of a new plant virus genus.
TL;DR: A simple assay was devised to analyze whether ToTV can be transmitted by whiteflies and strongly suggest that both B. tabaci and T. vaporariorum can transmit ToTV.
Abstract: Torrao or torrado is an emerging disease that is causing serious economic losses in tomato crops of southeastern Spain. The causal agent has been shown to be a new picorna-like plant virus, tentatively named Tomato torrado virus (ToTV) (4). By using trap tomato plants in a greenhouse affected by torrado located in the Murcia Region of Spain, we obtained a ToTV isolate (ToTV-CE) that we have biologically and molecularly characterized. Subtracted cDNA libraries (1) and expressed sequence tags sequencing were used to determine the partial nucleotide sequence of ToTV-CE. We covered ≈53% of the virus genome (GenBank Accession Nos. EU476181 and EU476182) and found that ToTV-CE RNAs 1 and 2 had a high nucleotide similarity (98 and 99%, respectively) with the ToTV published sequences (2,4). ToTV-CE sequences also showed a 70% nt similarity with those of Tomato apex necrosis virus, a newly identified virus in tomato crops of the Culiacan area (Sinaloa, Mexico) (3). To characterize the host range of ToTV-CE, 6 to 1...
TL;DR: The results altogether indicate a semi-persistent stylet-borne mode of vector transmission for torradoviruses, the first group of spherical viruses transmitted by at least three different species of whiteflies.