Submitted to: Journal of General Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/1995
Publication Date: N/A
Interpretive Summary: Apple mosaic virus (ApMV) is the causal agent of disease in many woody hosts species such as apple, roses, hazelnuts, filberts, birch, raspberries, and hops. Members of this group of plant viruses produce ringspot symptoms on their hosts. ApMV is transmitted by thrips, but it is not known to be spread through pollen. ApMV is very similar to rose mosaic virus. Its genetic material is contained on three small ribonucleic acid chromosomes. The smallest of these contains a gene that expresses a protein that allows the virus to move throughout the plant during infection. This protein has been identified as a possible point where the disease caused by the virus could be controlled. If the action of this gene could be blocked the virus would not be able to spread in plants and it would not cause disease. To understand how the protein facilitates virus movement and how the gene might be altered to produce a defective protein which could interfere with virus movement, the gene has been isolated and its precise chemical organization determined. The next step in these experiments will be to modify the gene and then introduce it into host plants to test the effects of the modifications on virus movement.
Technical Abstract: The complete nucleotide sequence of (ApMV) RNA 3 has been determined from cloned viral cDNAs. The 5' terminus of RNA 3 was determined by direct RNA sequencing, while the 3' end was determined by polyadenylation of genomic RNA and sub-cloning using oligo dT. ApMV RNA-3 is 2056 bases in length and contains at least two open reading frames. It is similar in size and genome organization to the RNA-3 of other members of the Bromoviridae, which includes ilarviruses. The coat protein (CP) gene is located at the 3' half of the molecule, and another large open reading frame is located upstream of the CP gene which can potentially encode a peptide of 32,400 daltons. This peptide is the same size and shows limited amino acid sequence homology to the open reading frames located at the 5' ends of RNA 3 of tobacco streak and prune dwarf ilarviruses and alfalfa mosaic virus, which are postulated to be viral movement proteins. No sequence homology was seen to either tobacco streak, prune dwarf, alfalfa mosaic virus or other members of the Bromoviridae at the nucleic acid level. The 5'-non-coding region of ApMV RNA-3 contains a 15 base palindromic sequence which encloses a sequence resembling the ICR-2 regions of eukaryotic tRNA gene promoters.