P. Mcgarvey et al., THE COMPLETE SEQUENCE OF A CUCUMBER MOSAIC-VIRUS FROM IXORA THAT IS DEFICIENT IN THE REPLICATION OF SATELLITE RNAS, Journal of General Virology, 76, 1995, pp. 2257-2270
A cucumber mosaic virus (CMV-Ix) from Ixora is unusual in that it does
not support the accumulation of some well-characterized CMV satellite
RNAs in plants. CMV-Ix can support a particular satellite RNA variant
which causes lethal tomato necrosis when inoculated with other CMV st
rains but not when inoculated with CMV-Ix. This difference in ability
to support accumulation of specific satellite variants is apparent eve
n when their sequences differ by only 10 nucleotides. Electroporation
of tomato protoplasts with combinations of CMV-Ix or CMV-1 RNA plus th
e same satellite variants showed similar differences in accumulation,
indicating a defect in satellite RNA replication and not movement or e
ncapsidation. Pseudorecombinant virus infections between CMV-1 and CMV
-Ix indicated that the genomic determinants responsible for this pheno
type reside on RNA 1 since only combinations with CMV-Ix RNA 1 failed
to replicate satellite RNA. The complete genome of CMV-Ix was cloned,
sequenced and compared with the genomes of other cucumoviruses. CMV-Ix
is most similar in RNA and protein sequence to subgroup 1 CMV-Fny and
CMV-Y but slightly less similar than they are to each other. CMV-Ix a
nd all cucumovirus strains sequenced thus far share a domain in the 3'
untranslated portion of their genomic RNAs in which 39 of 40 bases ar
e completely conserved.