Abstract
Transgenic tobacco plants engineered to express either the potato virus X (PVX) coat protein (CP+) or the antisense coat protein transcript (CP-antisense) were protected from infection by PVX, as indicated by reduced lesion numbers on inoculated leaves, delay or absence of systemic symptom development and reduction in virus accumulation in both inoculated and systemic leaves. The extent of protection observed in CP+ plants primarily depended upon the level of expression of the coat protein. Plants expressing antisense RNA were protected only at low inoculum concentrations. The extent of this protection was even lower than that observed in plants expressing low levels of CP. In contrast to previous reports for plants expressing tobacco mosaic virus or alfalfa mosaic virus CP, inoculation of plants expressing high levels of PVX CP with PVX RNA did not overcome the protection. Specifically, lesion numbers on inoculated leaves and PVX levels on inoculated and systemtic leaves of the CP+ plants were reduced to a similar extent in both virus and RNA inoculated plants. Although these results do not rule out that CP-mediated protection involves inhibition of uncoating of the challenge virus, they suggest that PVX CP (or its RNA) can moderate early events in RNA infection by a different mechanism.
Keywords: cross-protection, potato virus X, transgenic plants, coat protein, antisense RNA
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- A simple and general method for transferring genes into plants. Science. 1985 Mar 8;227(4691):1229–1231. doi: 10.1126/science.227.4691.1229. [DOI] [PubMed] [Google Scholar]
- Abel P. P., Nelson R. S., De B., Hoffmann N., Rogers S. G., Fraley R. T., Beachy R. N. Delay of disease development in transgenic plants that express the tobacco mosaic virus coat protein gene. Science. 1986 May 9;232(4751):738–743. doi: 10.1126/science.3457472. [DOI] [PubMed] [Google Scholar]
- Ecker J. R., Davis R. W. Inhibition of gene expression in plant cells by expression of antisense RNA. Proc Natl Acad Sci U S A. 1986 Aug;83(15):5372–5376. doi: 10.1073/pnas.83.15.5372. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HELMS K., McINTYRE G. A. Studies on size of lesions of tobacco mosaic virus on pinto bean. Virology. 1962 Dec;18:535–545. doi: 10.1016/0042-6822(62)90054-5. [DOI] [PubMed] [Google Scholar]
- Loesch-Fries L. S., Merlo D., Zinnen T., Burhop L., Hill K., Krahn K., Jarvis N., Nelson S., Halk E. Expression of alfalfa mosaic virus RNA 4 in transgenic plants confers virus resistance. EMBO J. 1987 Jul;6(7):1845–1851. doi: 10.1002/j.1460-2075.1987.tb02442.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Otten L. A., Schilperoort R. A. A rapid micro scale method for the detection of lysopine and nopaline dehydrogenase activities. Biochim Biophys Acta. 1978 Dec 8;527(2):497–500. doi: 10.1016/0005-2744(78)90363-7. [DOI] [PubMed] [Google Scholar]
- Rothstein S. J., Dimaio J., Strand M., Rice D. Stable and heritable inhibition of the expression of nopaline synthase in tobacco expressing antisense RNA. Proc Natl Acad Sci U S A. 1987 Dec;84(23):8439–8443. doi: 10.1073/pnas.84.23.8439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shepard J. F., Shalla T. A. Relative antigenic specificities of two PVX strains and their D-protein oligomers. Virology. 1972 Jan;47(1):54–60. doi: 10.1016/0042-6822(72)90238-3. [DOI] [PubMed] [Google Scholar]
- Sonenberg N., Shatkin A. J., Ricciardi R. P., Rubin M., Goodman R. M. Analysis of terminal structures of RNA from potato virus X. Nucleic Acids Res. 1978 Jul;5(7):2501–2512. doi: 10.1093/nar/5.7.2501. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tumer N. E., Clark W. G., Tabor G. J., Hironaka C. M., Fraley R. T., Shah D. M. The genes encoding the small subunit of ribulose-1,5-bisphosphate carboxylase are expressed differentially in petunia leaves. Nucleic Acids Res. 1986 Apr 25;14(8):3325–3342. doi: 10.1093/nar/14.8.3325. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tumer N. E., O'connell K. M., Nelson R. S., Sanders P. R., Beachy R. N., Fraley R. T., Shah D. M. Expression of alfalfa mosaic virus coat protein gene confers cross-protection in transgenic tobacco and tomato plants. EMBO J. 1987 May;6(5):1181–1188. doi: 10.1002/j.1460-2075.1987.tb02352.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wodnar-Filipowicz A., Skrzeczkowski L. J., Filipowicz W. Translation of potato virus X RNA into high molecular weight proteins. FEBS Lett. 1980 Jan 1;109(1):151–155. doi: 10.1016/0014-5793(80)81331-7. [DOI] [PubMed] [Google Scholar]