Molecular characterization of two alphacryptovirus dsRNAs isolated from Daucus carota

The genome of Beet cryptic virus 1 shows high homology to certain cryptoviruses present in phylogenetically distant hosts

“…The identical stretches include the terminal motif 5 0 -GAU-CAAAAGA-3 0 described by Blawid et al [11] for VCV dsRNA. A similarly high degree of identity in the whole 5 0 -UTRs to the corresponding WCCV1, VCV and CaCV sequences [11,14] was also obvious; although, the published WCCV1 sequences seem to be incomplete at their extreme 5 0 -ends. In all four viruses the 5 0 -UTR of dsRNA2 was longer than that of dsRNA1.…”

“…No other gene products have yet been described. Complete genome sequences are available for many fungal partitiviruses, currently classified in the genus Partitivirus, and during the last few years several sequences have been reported for plant viruses in the genus Alphacryptovirus, but none for betacryptoviruses [5][6][7][8][9][10][11][12][13][14]. Sequence comparisons fully support the relatedness of fungal and plant partitiviruses, moreover, they clearly show that similarity between certain plant and fungal viruses may be higher than similarity among the plant viruses [11].…”

“…While cloning and characterizing the BCV1 genome we found that it also shows a similarly high sequence identity to WCCV1 and VCV, and to the sequence of a carrot alphacryptovirus, published after we added our sequence in the GenBank database [6,7,11,14]. In this article, we describe the characteristic features of the BCV1 genome and discuss the possible evolutionary causes of the strong relatedness of cryptoviruses persisting in phylogenetically distant hosts.…”

“…The RdRp sequences of three plant cryptic viruses, namely those of the recently cloned CaCV (Carrot cryptic virus), as well as of WCCV1 and VCV showed 81-85% amino acid sequence identity to BCV1 without any gaps (Fig. S2 in Online Resource; [6,7,11,14]. The RdRp of two other viruses, Cherry chlorotic rusty spot associated partitivirus (CCRSPV) and Amasya cherry disease associated partitivirus (ACDPV) also show more than 50% identity (not shown in Fig.…”

“…dsRNA2 encodes the viral CP All cryptoviruses are known to encode their own RdRp and one or two CPs [12,14]. Since the BCV1 genome consists of two segments, it was expected that the CP would be encoded by the large open reading frame (ORF) on dsRNA2.…”