Molecular characterization of a closterovirus from carrot and its identification as a German isolate of Carrot yellow leaf virus
A high-molecular-weight dsRNA (~15 kbp) was isolated from chlorotic leaves of a carrot plant and used for determining the entire nucleotide sequence of a closterovirus. The complete genome of this carrot closterovirus (CCV) was 16.4 kb in length and contained ten open reading frames (ORFs). The genome organization of CCV resembled that of beet yellow stunt virus, but ORF2 and ORF3 were in a reversed order. Based on Hsp70h sequences, CCV is most closely related to carnation necrotic fleck virus and mint virus 1, two viruses of the genus Closterovirus (family Closteroviridae). The major coat protein gene of CCV was expressed in Escherichia coli for raising an antiserum. This permitted routine detection of CYLV by DAS-ELISA and immunoelectron microscopy and was used for demonstrating the bipolar nature of the CCV virion. Moreover, the antiserum gave a Western blot reaction with a reference sample of a Carrot yellow leaf virus (CYLV) isolate from the Netherlands, suggesting that CCV is a German isolate of CYLV.
KeywordsCoat Protein Citrus Tristeza Virus Carrot Plant Beet Yellow Virus German Isolate
The authors thank R. van der Vlugt (Wageningen, The Netherlands) for providing a dried leaf sample of the Dutch CYLV isolate. This work was part of a study supported by the German Ministry of Food, Agriculture and Consumer Protection under project no. 02OE253.
- 7.Febres VJ, Ashoulin L, Mawassi M, Frank A, Bar-Joseph M, Manjunath KL, Lee RF, Niblett CL (1996) The p27 protein is present at one end of citrus tristeza virus particles. Phytopathology 86:1331–1335Google Scholar
- 11.Martelli GP, Agranovsky AA, Bar-Joseph M, Boscia D, Candresse T, Coutts RHA, Dolja VV, Falk BW, Gonsalves D, Hu JS, Jelkmann W, Karasev AV, Minafra A, Namba S, Vetten HJ, Wisler CG, Yoshikawa N (2005) Closteroviridae. In: Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA (eds) Virus taxonomy. Academic Press, London, pp 1077–1087Google Scholar
- 12.Milne RG, Lesemann D-E (1984) Immunosorbent electron microscopy in plant virus studies. Methods Virol 8:5–101Google Scholar
- 19.van Dijk P, Bos L (1996) Carrot yellow leaf virus. In: Brunt AA, Crabtree K, Dallwitz MJ, Gibbs AJ, Watson L (eds) Viruses of Plants. Descriptions and Lists from the VIDE Database. CAB International, pp 325–326Google Scholar
- 21.Yamashita S, Ohki S, Doi Y, Yora K (1976) Identification of two viruses associated with the carrot yellow leaf syndrome. Ann Phytopathol Soc Jpn 42:382–383 (in Japanese)Google Scholar