1887

Abstract

Hypovirulent isolates of the fruit tree fungal pathogen have previously been shown to harbour a double-stranded (ds)RNA genetic element of about 4 kb. In this study, we established the complete cDNA sequence of this dsRNA, which represents a replicative form of a positive-strand RNA virus that we have named (DaRV). The nucleotide sequence of the genome is 4113 bp and has a GC content of 53%. Two large ORFs are present in the same reading frame. They are most probably translated by readthrough of a UAG stop codon in the central part of the genome. The longest possible translation product (p125) has a predicted molecular mass of about 125 kDa. A significant homology can be found to the non-structural proteins of carmoviruses of the positive-strand RNA virus family . These proteins also include the conserved RNA-dependent RNA polymerase (RDRP) domain. In contrast to the genome organization of these plant viruses, no ORF is present at the 3′ end of the DaRV genome that encodes a coat protein. Therefore, it is proposed that DaRV is not encapsidated but that it occurs as RNA–RDRP complexes and/or that it might be associated with cell membranes. Interestingly, six putative transmembrane helices are predicted in the N-terminal part of p56 (translation product of the first ORF, N-terminal part of p125), which might direct and anchor the viral complex to membranes. DaRV is a mycovirus with a unique genome organization and has a distant relationship to the plant virus family .

Loading

Article metrics loading...

/content/journal/jgv/10.1099/0022-1317-81-12-3107
2000-12-01
2024-04-16
Loading full text...

Full text loading...

/deliver/fulltext/jgv/81/12/0813107a.html?itemId=/content/journal/jgv/10.1099/0022-1317-81-12-3107&mimeType=html&fmt=ahah

References

  1. Anagnostakis S. L., Waggoner P. E. 1981; Hypovirulence, vegetative incompatibility, and the growth of cankers of chestnut blight. Phytopathology 71:1198–1202
    [Google Scholar]
  2. Carrington J. C., Heaton L. A., Zuidema D., Hillman B. I., Morris T. J. 1989; The genome structure of turnip crinkle virus. Virology 170:219–226
    [Google Scholar]
  3. Fahima T., Kazmierczak P., Hansen D. R., Pfeiffer P., van Alfen N. K. 1993; Membrane-associated replication of an unencapsidated double-strand RNA of the fungus, Cryphonectria parasitica. Virology 195:81–89
    [Google Scholar]
  4. Frohman M. A. 1994; On beyond classic RACE (rapid amplification of cDNA ends). PCR Methods and Applications 4:S40–S58
    [Google Scholar]
  5. García-Cuéllar M. P., Esteban R., Fujimura T. 1997; RNA-dependent RNA polymerase activity associated with the yeast viral p91/20S RNA ribonucleoprotein complex. RNA 3:27–36
    [Google Scholar]
  6. Ghabrial S. A. 1998; Origin, adaptation and evolutionary pathways of fungal viruses. Virus Genes 16:119–131
    [Google Scholar]
  7. Gubler U., Hoffmann B. J. 1983; A simple and very efficient method for generating cDNA libraries. A simple and very efficient method for generating cDNA libraries. Gene 25:263–269
    [Google Scholar]
  8. Guilley H., Carrington J. C., Balazs E., Jonard G., Richards K., Morris T. J. 1985; Nucleotide sequence and genome organization of carnation mottle virus. Nucleic Acids Research 13:6663–6677
    [Google Scholar]
  9. Hacker D. L., Petty I. T. D., Wei N., Morris T. J. 1992; Turnip crinkle virus genes required for RNA replication and virus movement. Virology 186:1–8
    [Google Scholar]
  10. Hammar S., Fulbright D. W., Adams G. C. 1989; Association of double-stranded RNA with low virulence in an isolate of Leucostoma persoonii. Phytopathology 79:568–572
    [Google Scholar]
  11. Hansen D. R., van Alfen N. K., Gillies K., Powell W. A. 1985; Naked dsRNA associated with hypovirulence of Endothia parasitica is packaged in fungal vesicles. Journal of General Virology 66:2605–2614
    [Google Scholar]
  12. Heiniger U., Rigling D. 1994; Biological control of chestnut blight in Europe. Annual Review of Phytopathology 32:581–599
    [Google Scholar]
  13. Hong Y., Cole T. E., Brasier C. M., Buck K. W. 1998; Evolutionary relationships among putative RNA-dependent RNA polymerases encoded by a mitochondrial virus-like RNA in the Dutch elm disease fungus, Ophiostoma novo-ulmi , by other viruses and virus-like RNAs and by the Arabidopsis mitochondrial genome. Virology 246:158–169
    [Google Scholar]
  14. Hong Y., Dover S. L., Cole T. E., Brasier C. M., Buck K. W. 1999; Multiple mitochondrial viruses in an isolate of the Dutch elm disease fungus Ophiostoma novo-ulmi. Virology 258:118–127
    [Google Scholar]
  15. Huang S., Ghabrial S. A. 1996; Organization and expression of the double-stranded RNA genome of Helminthosporium victoriae 190S virus, a totivirus infecting a plant pathogenic filamentous fungus. Proceedings of the National Academy of Sciences, USA 93:12541–12546
    [Google Scholar]
  16. Klein P., Kanehisa M., DeLisi C. 1985; The detection and classification of membrane-spanning proteins. Biochimica et Biophysica Acta 815:468–476
    [Google Scholar]
  17. Koonin E. V., Dolja V. V. 1993; Evolution and taxonomy of positive-strand RNA viruses: Implications of comparative analysis of amino acid sequences. Critical Reviews in Biochemistry and Molecular Biology 28:375–430
    [Google Scholar]
  18. Koonin E. V., Choi G. H., Nuss D. L., Shapira R., Carrington J. C. 1991; Evidence for common ancestry of a chestnut blight hypovirulence-associated double-stranded RNA and a group of positive-strand RNA plant viruses. Proceedings of the National Academy of Sciences, USA 88:10647–10651
    [Google Scholar]
  19. Liu Y.-C., Milgroom M. G. 1996; Correlation between hypovirus transmission and the number of vegetative incompatibility ( vic ) genes different among isolates from a natural population of Cryphonectria parasitica. Phytopathology 86:79–86
    [Google Scholar]
  20. Nuss D. L. 1992; Biological control of chestnut blight: an example of virus-mediated attenuation of fungal pathogenesis. Microbiological Reviews 56:561–576
    [Google Scholar]
  21. O’Reilly E. R., Kao C. C. 1998; Analysis of RNA-dependent RNA polymerase structure and function as guided by known polymerase structures and computer predictions of secondary structure. Virology 252:287–303
    [Google Scholar]
  22. Patel P. H., Loeb L. A. 2000; DNA polymerase active site is highly mutable: evolutionary consequences. Proceedings of the National Academy of Sciences, USA 97:5095–5100
    [Google Scholar]
  23. Preisig O., Wingfield B. D., Wingfield M. J. 1998; Coinfection of a fungal pathogen by two distinct double-stranded RNA viruses. Virology 252:399–406
    [Google Scholar]
  24. Revill P. A., Davidson A. D., Wright P. J. 1999; Identification of a subgenomic mRNA encoding the capsid protein of mushroom bacilliform virus, a single-stranded RNA mycovirus. Virology 260:273–276
    [Google Scholar]
  25. Rubino L., Russo M. 1998; Membrane targeting sequences in tombusvirus infections. Virology 252:431–437
    [Google Scholar]
  26. Rubino L., Di Franco A., Russo M. 2000; Expression of a plant virus non-structural protein in Saccharomyces cerevisiae causes membrane proliferation and altered mitochondrial morphology. Journal of General Virology 81:279–286
    [Google Scholar]
  27. Russo M., Martelli G. P. 1982; Ultrastructure of turnip crinkle- and saguaro cactus virus-infected tissues. Virology 118:109–116
    [Google Scholar]
  28. Schaad M. C., Jensen P. E., Carrington J. C. 1997; Formation of plant RNA virus replication complexes on membranes: role of an endoplasmic reticulum-targeted viral protein. EMBO Journal 16:4049–4059
    [Google Scholar]
  29. Schnell M. J., Conzelmann K.-K. 1995; Polymerase activity of in vitro mutated rabies virus L protein. Virology 214:522–530
    [Google Scholar]
  30. Shapira R., Choi G. H., Nuss D. L. 1991; Virus-like genetic organization and expression strategy for a double-stranded RNA genetic element associated with biological control of chestnut blight. EMBO Journal 10:731–739
    [Google Scholar]
  31. Skuzeski J. M., Nichols L. M., Gesteland R. F., Atkins J. F. 1991; The signal for a leaky UAG stop codon in several plant viruses includes the two downstream codons. Journal of Molecular Biology 218:365–373
    [Google Scholar]
  32. Smit W. A., Viljoen C. D., Wingfield B. D., Wingfield M. J., Calitz F. J. 1996a; A new canker disease of apple, pear and plum rootstocks caused by Diaporthe ambigua in South Africa. Plant Disease 80:1331–1335
    [Google Scholar]
  33. Smit W. A., Wingfield B. D., Wingfield M. J. 1996b; Reduction of laccase activity and other hypovirulence-associated traits in dsRNA-containing strains of Diaporthe ambigua. Phytopathology 86:1311–1316
    [Google Scholar]
  34. Smit W. A., Wingfield B. D., Wingfield M. J. 1998; Integrated approach to controlling Diaporthe canker of deciduous fruit in South Africa. Recent Research Developments in Plant Pathology 2:43–62
    [Google Scholar]
  35. Steenkamp E. T., Wingfield B. D., Swart W. J., Wingfield M. J. 1998; Double-stranded RNA and associated virulence in South African isolates of Sphaeropsis sapinea. Canadian Journal of Botany 76:1412–1417
    [Google Scholar]
  36. Valverde R. A., Nameth S. T., Jordan R. L. 1990; Analysis of double-stranded RNA for plant virus diagnostics. Plant Disease 74:255–258
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/jgv/10.1099/0022-1317-81-12-3107
Loading
/content/journal/jgv/10.1099/0022-1317-81-12-3107
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error