Analysis of the dsRNAs of apple chlorotic leaf spot virus

Abstract

Double-stranded RNAs were isolated from plants infected with five different isolates of apple chlorotic leaf spot virus (ACLSV). Analysis by PAGE and by Northern blot hybridization showed that six major species of viral dsRNA of approximately 7-5, 6.4, 5-4, 2-2, 1-1 and 1.0 kbp can be detected in infected plants, irrespective of the ACLSV isolate used. In addition to the dsRNA of 7.5 kbp corresponding to the full-length genome, the size and position on the genome of the 2-2 and 1-1 kbp species indicate that these are very probably double-stranded forms of subgenomic RNAs allowing the expression of the internal open reading frames coding respectively for the ACLSV 50K and coat proteins. The subgenomic messenger for the coat protein was indeed detected in total RNA preparations from infected plants. Surprisingly, the two most abundant dsRNA species, of 6-4 and 5.4 kbp, were found to be 5'-coterminal with the genomic RNA. A model for the expression of the genome of ACLSV and for the production of the molecules 5'-coterminal with the genomic RNA is presented.

Purification and Characterization of Peach Mosaic Virus

“…The size of the PMV genomic RNA (8.1 kb) is similar to that reported for lettuce infectious yellows closterovirus (13), larger than the 6.5 kb reported for capilloviruses (19), but similar to the 7.5 to 8.7 reported for trichoviruses (17). The multiple high molecular mass dsRNA bands found for PMV are not consistent with those found for closteroviruses (7); however, multiple high molecular mass dsRNA bands have been described for trichoviruses (10). We suggest that PMV appears to be most closely related to trichoviruses, in contrast to the report that CMLV is likely a closterovirus (11).…”

Complete nucleotide sequence of the genome of an apple isolate of apple chlorotic leaf spot virus

“…The products (51K and 23K proteins) detected in translation experiments may be synthesized from fragmented RNAs of ACLSV-A RNA because the proteins encoded by ORFs 2 and 3 are thought to be translated from subgenomic RNAs (German et al, 1992). The M r (21.4K) of the protein encoded by ORF 3 of ACLSV-A agrees with that of the ACLSV-A coat protein M r estimated by PAGE (Yoshikawa & Takahashi, 1988).…”

The closteroviruses, capilloviruses and other similar viruses: a short review

“…Identical dsRNA patterns are induced by five isolates of the virus (German et al, 1992). Using cDNA probes to various regions of the ACLV genome a total of six dsRNAs (I to VI) were detected and mapped to particular areas of the genome.…”

“…dsRNA extracts from plants infected with the subgroup B/C closteroviruses BYV, CNFV (which are serologically related) and CTV exhibit very similar patterns. Extracts of plants infected with different strains of CTV have distinguishable dsRNA patterns which can be used to differentiate between them (Dodds et al, 1987;Guerri et al, 1991 ;Moreno et al, 1990), but all the patterns are broadly similar in the number and spacing of the major bands, dsRNA has also been isolated from a number of other clostero-like virus infections including plants infected with grapevine corky bark, a virus German et al, 1992). (b) PAGE (Dodds & Bar-Joseph, 1983).…”