Complete genome sequence of lettuce chordovirus 1 isolated from cultivated lettuce in France

Abstract

Double-stranded RNAs purified from cultivated (Lactuca sativa) or wild (L. serriola) lettuce from southwest France were analyzed by high-throughput sequencing. For both samples, BLAST annotation revealed contigs with homology to Betaflexiviridae family members. The full genome sequence of the isolate from cultivated lettuce (JG1) was completed (8,536 nucleotides [nt], excluding the poly(A) tail). The sequence of the 3' half of the genome (4,800 nt) of a wild lettuce isolate (P22) was determined and found to share 95.1% nt sequence identity with the JG1 isolate. The JG1 genome contains four open reading frames, encoding a replicase, a movement protein, a capsid protein, and a protein of unknown function, respectively. Based on genome organization and phylogenetic relationships, the lettuce virus is most closely related to the recently described carrot chordoviruses 1 and 2 in the family Betaflexiviridae. Considering the species demarcation criteria in this family, the two lettuce viruses represent isolates of a new chordovirus species for which the name "lettuce chordovirus 1" (LeCV1) is proposed.

Molecular and Biological Characterization of Novel and Known Family Secoviridae Members Infecting Lettuce

“…Trocadéro) failed (data not shown). The same was observed for LeCV1 (Svanella-Dumas et al 2018). These observations are consistent with the notion that waikaviruses are not mechanically sap-transmissible because they are confined to phloem tissue (Reavy et al 1993).…”

“…In recent years, several novel viruses have been characterized in lettuce crops (Ciuffo et al 2016;Svanella-Dumas et al 2018, Verbeek et al 2014, while the main viruses infecting lettuce in Europe or in Central America have been respectively reviewed in Moreno et al (2012) and Pavan et al (2008). Lettuce mosaic virus (LMV, Potyvirus) is probably the most important virus of lettuce worldwide (Pavan et al 2008).…”

Carrot populations in France and Spain host a complex virome rich in previously uncharacterized viruses

“…Another group of +ssRNA viruses identified is this study involves the family Betaflexiviridae . The genus Chordovirus was recently accepted within the family Betaflexiviridae ( https://ictv.global/taxonomy ) and comprises carrot chordovirus 1 and 2 (CChV1 and CChV2), identified in the UK [ 16 ], lettuce chordovirus 1 identified in lettuce in France [ 56 ] and hogweed virus 4 (OK032418) recently characterized from a historical UK hogweed sample [ 57 ]. We identified two novel chordoviruses, CChV3 and CChV4 as well as a novel vitivirus, CaVV1.…”