Searching for a New Putative Cryptic Virus in Pinus sylvestris L
Double-stranded RNAs (dsRNAs) were detected in different pine populations in Germany and Hungary. Two dsRNA species of 1.5 and 1.58 kbp, respectively, persisted in the same trees for at least 2 years and their presence was not associated with any symptoms. The dsRNAs were found to sediment in the VLP (virus-like particles) fraction and to be protected by protein(s) against RNase A digestion at low salt. cDNA cloning and sequencing of the smaller segment (dsRNA2) led to the identification of a putative RNA-dependent RNA-polymerase (RdRp) containing the GDD, as well as three other, conserved motifs. Sequence comparison with different RNA viruses and phylogenetic analysis indicates that the putative RdRp from pine shows highest similarity to the homologous proteins of Beet cryptic virus 3 and of a cryptic virus of Pyrus pyrifolia. On the basis of these results we suggest that the 1.5 and 1.58 kbp dsRNAs in P. sylvestris may represent the genomic segments of a new plant cryptic virus, Cryptoviruses have not yet been reported to occur in Gymnosperms.
KeywordsCryptovirus dsRNA Pinus sylvestris Partitiviridae RNA-dependent RNA polymerase
This project was supported by Grants OTKA T032861 and DFG Lu 386/1–2. We thank Drs. I. Szabó and S. Bogya for providing us with pine samples and Dr. L. Vajna for advise on endophytic fungi. We are grateful to M. Kutzner, E. Bárdosi and G. Fleit for technical help and to Dr. P. Symmons and E. Bába for helping us with the manuscript.
- 4.S. Miyazaki, K. Iwabuchi, J.Y. Pak, T. Fukuhara, T. Nitta, Insect Biochem. Mol. Biol. 26, 955–961 (1996)Google Scholar
- 11.A.M. Pirtilla, H. Pospiech, H. Laukkanen, R. Myllyla, A. Hohtola, Microb. Ecol. 45(1), 53–62 (2003)Google Scholar
- 12.B. Ziegenhagen, P. Guillemaut, E. Scholz, Plant Mol. Biol. Rep. 11, 117–121 (1993)Google Scholar
- 14.J. Sambrook, E.F. Fritsch, T. Maniatis, Molecular Cloning: A Laboratory Manual, 2nd edn. (Cold Spring Harbor, Cold Spring Harbor Laboratory, NY, 1989)Google Scholar
- 15.M. Flachmann, Ph.D. thesis, University Hohenheim, (1992), pp. 83–85Google Scholar
- 17.Y.G. Choi, B.J. Croft, J.W. Randles, Phytopathology 89, 877–883 (1999)Google Scholar
- 30.L. Covelli, R.H. Coutts, F. Di Serio, A. Citir, S. Acikgoz, C. Hernandez, A. Ragozzino, R.J. Flores, Gen. Virol. 85, 3389–3397 (2004)Google Scholar
- 34.H. Osaki, K. Nomura, T. Iwanami, S. Kanematsu, I. Okabe, N. Matsumoto, A. Sasaki, Y. Ohtsu, Tanaka Virus Genes 25, 139–145 (2002)Google Scholar
- 37.K. Ihrmark, J. Zheng, E. Stenstrom, J. Stenlid, For. Pathol. 31, 387–394 (2001)Google Scholar
- 38.K. Ihrmark, Ph.D. thesis, Swedish University of Agricultural sciences, Uppsala, Sweden, (2001)Google Scholar
- 48.S.A. Ghabrial, K.W. Buck, B.I. Hillman, R.G. Milne, in Eighth Report of the International Committee on Taxonomy of Viruses. ed. by C.M. Fauquet, M.A. Mayo, J. Maniloff, U. Desselberger, A.L. Ball (Elsevier/Academic press, London, 2005)Google Scholar
- 49.N. Enünlü, D. Veliceasa, S. Deshmukh, B. Morgun, V. Stepanyuk, S. Köster, N. Lukács, in 8th International Congress in Plant Pathology, Christchurch, New Zealand, 2–7 February 2003, A17.6Google Scholar