Skip to main content
PMC home page
The EMBO Journal logoLink to The EMBO Journal
. 1986 Sep;5(9):2051–2055. doi: 10.1002/j.1460-2075.1986.tb04465.x

Replication of in vitro constructed viroid mutants: location of the pathogenicity-modulating domain of citrus exocortis viroid

Jane E Visvader 1,1, Robert H Symons 1
PMCID: PMC1167081  PMID: 16453700

Abstract

Sequence variants from field isolates of citrus exocortis viroid (CEV) that cause either mild or severe symptoms on tomato plants have previously been classified into two groups, A and B. These groups differ primarily in two domains, PL and PR, of the proposed native structure. Infectivity studies with full-length cDNA clones of variants from each class have now directly confirmed the original correlation between Class A sequences and the severe phenotype and between Class B sequences and the mild phenotype. Direct evidence for this correlation could only be obtained by using individual sequence variants since field isolates of CEV have been shown to contain a mixture of RNA species. The construction and infectivity of chimaeric cDNA clones derived from mild and severe sequence variants of CEV has demonstrated that novel, infectious viroid molecules can be generated in vitro, and that PL is the pathogenicity-modulating domain. The role of the PR domain is not known but infectivity experiments with one chimaeric cDNA clone suggest that it may influence the efficiency of the infection or replication process of the viroid in the plant.

Keywords: citrus exocortis viroid, chimaeric cDNA clones, infectivity studies

Full text

PDF
2051

Images in this article

2053Fig. 2.
on p.2053
2054Fig. 4.
on p.2054

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Diener T. O. Viroids. Adv Virus Res. 1983;28:241–283. doi: 10.1016/s0065-3527(08)60725-3. [DOI] [PubMed] [Google Scholar]
  2. Gould A. R., Symons R. H. Cucumber mosaic virus RNA 3. Determination of the nucleotide sequence provides the amino acid sequences of protein 3A and viral coat protein. Eur J Biochem. 1982 Aug;126(2):217–226. [PubMed] [Google Scholar]
  3. Gross H. J., Krupp G., Domdey H., Raba M., Jank P., Lossow C., Alberty H., Ramm K., Sänger H. L. Nucleotide sequence and secondary structure of citrus exocortis and chrysanthemum stunt viroid. Eur J Biochem. 1982 Jan;121(2):249–257. doi: 10.1111/j.1432-1033.1982.tb05779.x. [DOI] [PubMed] [Google Scholar]
  4. Gross H. J., Liebl U., Alberty H., Krupp G., Domdey H., Ramm K., Sänger H. L. A severe and a mild potato spindle tuber viroid isolate differ in three nucleotide exchanges only. Biosci Rep. 1981 Mar;1(3):235–241. doi: 10.1007/BF01114910. [DOI] [PubMed] [Google Scholar]
  5. Haseloff J., Symons R. H. Chrysanthemum stunt viroid: primary sequence and secondary structure. Nucleic Acids Res. 1981 Jun 25;9(12):2741–2752. doi: 10.1093/nar/9.12.2741. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ishikawa M., Meshi T., Okada Y., Sano T., Shikata E. In vitro mutagenesis of infectious viroid cDNA clone. J Biochem. 1985 Dec;98(6):1615–1620. doi: 10.1093/oxfordjournals.jbchem.a135431. [DOI] [PubMed] [Google Scholar]
  7. Keese P., Symons R. H. Domains in viroids: evidence of intermolecular RNA rearrangements and their contribution to viroid evolution. Proc Natl Acad Sci U S A. 1985 Jul;82(14):4582–4586. doi: 10.1073/pnas.82.14.4582. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kiefer M. C., Owens R. A., Diener T. O. Structural similarities between viroids and transposable genetic elements. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6234–6238. doi: 10.1073/pnas.80.20.6234. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Melton D. A., Krieg P. A., Rebagliati M. R., Maniatis T., Zinn K., Green M. R. Efficient in vitro synthesis of biologically active RNA and RNA hybridization probes from plasmids containing a bacteriophage SP6 promoter. Nucleic Acids Res. 1984 Sep 25;12(18):7035–7056. doi: 10.1093/nar/12.18.7035. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Riesner D., Gross H. J. Viroids. Annu Rev Biochem. 1985;54:531–564. doi: 10.1146/annurev.bi.54.070185.002531. [DOI] [PubMed] [Google Scholar]
  11. Riesner D., Henco K., Rokohl U., Klotz G., Kleinschmidt A. K., Domdey H., Jank P., Gross H. J., Sänger H. L. Structure and structure formation of viroids. J Mol Biol. 1979 Sep 5;133(1):85–115. doi: 10.1016/0022-2836(79)90252-3. [DOI] [PubMed] [Google Scholar]
  12. Sanger F., Coulson A. R., Barrell B. G., Smith A. J., Roe B. A. Cloning in single-stranded bacteriophage as an aid to rapid DNA sequencing. J Mol Biol. 1980 Oct 25;143(2):161–178. doi: 10.1016/0022-2836(80)90196-5. [DOI] [PubMed] [Google Scholar]
  13. Schnölzer M., Haas B., Raam K., Hofmann H., Sänger H. L. Correlation between structure and pathogenicity of potato spindle tuber viroid (PSTV). EMBO J. 1985 Sep;4(9):2181–2190. doi: 10.1002/j.1460-2075.1985.tb03913.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Visvader J. E., Forster A. C., Symons R. H. Infectivity and in vitro mutagenesis of monomeric cDNA clones of citrus exocortis viroid indicates the site of processing of viroid precursors. Nucleic Acids Res. 1985 Aug 26;13(16):5843–5856. doi: 10.1093/nar/13.16.5843. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Visvader J. E., Gould A. R., Bruening G. E., Symons R. H. Citrus exocortis viroid: nucleotide sequence and secondary structure of an Australian isolate. FEBS Lett. 1982 Jan 25;137(2):288–292. doi: 10.1016/0014-5793(82)80369-4. [DOI] [PubMed] [Google Scholar]
  16. Visvader J. E., Symons R. H. Eleven new sequence variants of citrus exocortis viroid and the correlation of sequence with pathogenicity. Nucleic Acids Res. 1985 Apr 25;13(8):2907–2920. doi: 10.1093/nar/13.8.2907. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The EMBO Journal are provided here courtesy of Nature Publishing Group

RESOURCES