Search

Next-generation sequencing (NGS) allowed the assembly of the complete RNA-1 and RNA-2 sequences of a grapevine isolate of artichoke Italian latent virus (AILV). RNA-1 and RNA-2 are 7,338 and 4,630 nucleotides in length excluding the 3' terminal poly(A) tail, and encode two putative polyproteins of 255.8 kDa (p1) and 149.6 kDa (p2), respectively. All conserved motifs and predicted cleavage sites, typical for nepovirus polyproteins, were found in p1 and p2. AILV p1 and p2 share high amino acid identity with their homologues in beet ringspot virus (p1, 81% and p2, 71%), tomato black ring virus (p1, 79% and p2, 63%), grapevine Anatolian ringspot virus (p1, 65% and p2, 63%), and grapevine chrome mosaic virus (p1, 60% and p2, 54%), and to a lesser extent with other grapevine nepoviruses of subgroup A and C. Phylogenetic and sequence analyses, all confirmed the strict relationship of AILV with members classified in subgroup B of genus Nepovirus.

Previously characterized monoclonal antibodies (MAbs) to Grapevine virus A (GVA) showed a differential reactivity against intact or partially destabilized virus particles [2]. In the present study, this differential reactivity was confirmed and several peptides reacting with a panel of four different antibodies were identified by the PEPSCAN method of epitope mapping. Oligopeptide sequences comprised between coat protein residues 61 (V) and 72 (T) were recognized by all the antibodies tested. One of these peptides (VGPKASK) was also reactive when expressed on recombinant phage particles as a fusion protein with protein pVIII. The specificity of this sequence for antibody binding was also demonstrated by competitive-ELISA using one of the GVA MAbs. The results of this study suggest that GVA particles carry a highly structured epitope centered on a common peptide region of the coat protein sequence.

plants showing conspicuous concentric chrome-yellow bands in the leaves, from which itwas described and derived its name [9, 5]. New records from tomato came later from Italy[4], Spain [7] and France [6]. The Italian tomato isolate was characterized by Gallitelli [4].PZSV has a tripartite genome, particles morphologically similar to those of ilarviruses andgeneral properties resembling those of tripartite genome viruses of the family