Purification and properties of blackberry chlorotic ringspot, a new virus species in subgroup 1 of the genus Ilarvirus found naturally infecting blackberry in the UK

Abstract

A mechanically transmissible virus was isolated from Bedford Giant blackberry plants showing chlorotic mottling and ringspot symptoms growing in Scotland. It infected several herbaceous test plants, many of them symptomlessly. This virus was also transmitted to several Rubus species and cultivars by graft inoculation with scions from the field-infected Bedford Giant plant. Most grafted plants were infected symptomlessly, but Himalaya Giant blackberry and the hybrid berry Tayberry developed symptoms similar to those in the infected Bedford Giant plant. In the sap of infected Chenopodium quinoa, the virus lost infectivity when diluted 10 24 but not 10 23 , after 6 h and 48 h when kept at 20°C and 4°C, respectively, but was infective for more than 8 days when kept at 215°C. Preparations of purified virus from infected C. quinoa or spinach sedimented as three major nucleoprotein components and consisted of quasiisometric particles that varied in size from 24 to 32 nm in diameter and that were not penetrated by negative stain. Such virus particle preparations contained a major polypeptide of ca 28 kDa and three single-stranded RNA species of estimated size 3.2, 2.8 and 2.1 kb. The complete sequence of the largest RNA (RNA 1, 3478 nt) and the partial sequence of the other RNAs (1863 and 2102 nt long, respectively) were determined and compared with sequences in databases. These findings, together with the biological and biochemical properties of this virus, indicate that it should be regarded as a distinct species in subgroup 1 of the genus Ilarvirus even though it was serologically unrelated to existing members of this subgroup. The virus showed a very distant serological relationship with prune dwarf virus (PDV) but differed significantly from it in the amino acid sequence of its coat protein, experimental host range and symptomatology and was unrelated to PDV at the molecular level. The virus, tentatively named blackberry chlorotic ringspot virus, is therefore a newly described virus and the first ilarvirus found naturally infecting Rubus in the UK.

Characterisation of a novel ilarvirus causing grapevine angular mosaic disease

“…In addition, efficient purification and detection methods were developed. Phylogenetic analysis places GAMV in the genus Ilarvirus and more specifically in its subgroup 1, along with Tobacco streak virus (TSV), Strawberry necrotic shock virus (SNSV) (Tzanetakis et al 2004), Blackberry chlorotic ring spot virus (BCRV) (Jones et al 2006), and Parietaria mottle virus (PMoV) .…”

Pest categorisation of non‐EU viruses of Rubus L.

“…EU distribution of non-EU viruses of Rubus (those viruses not reported in the EU are excluded from this table)Reported only once in the UK in a few plants of a single cultivar(Jones et al, 2006) …”

Genome activation by raspberry bushy dwarf virus coat protein

“…Experiments have shown that the AMV CP and TSV CP can functionally substitute for one another. To examine the similarities in genome activation of RBDV, AMV and TSV, we tested whether expression of either the AMV, TSV or BCRV, a Rubus-infecting ilarvirus (Jones et al, 2006), CP gene from a binary plasmid could activate replication of agroinfiltrated RBDV RNA1 and RNA2. In each case, the CPs from these different viruses did not activate RBDV replication (Supplementary Table S2, Fig.…”