Abstract
Brome mosaic virus (BMV) is a positive-strand RNA virus with a multipartite genome that causes symptomless infection in Nicotiana benthamiana. We have isolated and characterized a strain of BMV that produced uniform vein chlorosis in systemically infected N. benthamiana. Analysis of pseudorecombinants constructed by exchanging RNA 1 and 2 and RNA 3 components between wild-type (non-symptom-inducing) and vein chlorosis-inducing strains of BMV indicated that the genetic determinant for the induction of the chlorotic phenotype is located on RNA 3. Sequence analysis of progeny RNA 3 recovered from symptomatic N. benthamiana plants revealed that vein chlorosis is due to the single nucleotide transition 887G-->887A, which changes the codon for Val-266 to Ile-266 in the movement protein gene. The mutation had no detectable effect on the accumulation of virus in either inoculated or systematically infected leaves of N. benthamiana. The vein chlorosis phenotype is the manifestation of the substitution of Ile-266 for Val-266 in the movement protein gene, since additional alterations in this region (a silent mutation, i.e., 887GUU889-->GUC, and an alteration of valine to phenylalanine, i.e., 887GUU889-->887UUU889) resulted in symptomless infections on N. benthamiana. The modulation of the symptom phenotype by the substitution of Ile-266 for Val-266 is specific for N. benthamiana, since neither movement nor the symptom phenotype in barley plants was affected.
Full Text
The Full Text of this article is available as a PDF (252.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dreher T. W., Rao A. L., Hall T. C. Replication in vivo of mutant brome mosaic virus RNAs defective in aminoacylation. J Mol Biol. 1989 Apr 5;206(3):425–438. doi: 10.1016/0022-2836(89)90491-9. [DOI] [PubMed] [Google Scholar]
- Melcher U. Similarities between putative transport proteins of plant viruses. J Gen Virol. 1990 May;71(Pt 5):1009–1018. doi: 10.1099/0022-1317-71-5-1009. [DOI] [PubMed] [Google Scholar]
- Mise K., Allison R. F., Janda M., Ahlquist P. Bromovirus movement protein genes play a crucial role in host specificity. J Virol. 1993 May;67(5):2815–2823. doi: 10.1128/jvi.67.5.2815-2823.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rao A. L., Dreher T. W., Marsh L. E., Hall T. C. Telomeric function of the tRNA-like structure of brome mosaic virus RNA. Proc Natl Acad Sci U S A. 1989 Jul;86(14):5335–5339. doi: 10.1073/pnas.86.14.5335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rao A. L., Grantham G. L. Amplification in vivo of brome mosaic virus RNAs bearing 3' noncoding region from cucumber mosaic virus. Virology. 1994 Oct;204(1):478–481. doi: 10.1006/viro.1994.1559. [DOI] [PubMed] [Google Scholar]
- Rao A. L., Hall T. C. Recombination and polymerase error facilitate restoration of infectivity in brome mosaic virus. J Virol. 1993 Feb;67(2):969–979. doi: 10.1128/jvi.67.2.969-979.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rao A. L., Sullivan B. P., Hall T. C. Use of Chenopodium hybridum facilitates isolation of brome mosaic virus RNA recombinants. J Gen Virol. 1990 Jun;71(Pt 6):1403–1407. doi: 10.1099/0022-1317-71-6-1403. [DOI] [PubMed] [Google Scholar]
- Sarkar G., Sommer S. S. The "megaprimer" method of site-directed mutagenesis. Biotechniques. 1990 Apr;8(4):404–407. [PubMed] [Google Scholar]
- Shintaku M. H., Zhang L., Palukaitis P. A single amino acid substitution in the coat protein of cucumber mosaic virus induces chlorosis in tobacco. Plant Cell. 1992 Jul;4(7):751–757. doi: 10.1105/tpc.4.7.751. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsai C. H., Dreher T. W. Increased viral yield and symptom severity result from a single amino acid substitution in the turnip yellow mosaic virus movement protein. Mol Plant Microbe Interact. 1993 May-Jun;6(3):268–273. doi: 10.1094/mpmi-6-268. [DOI] [PubMed] [Google Scholar]