Abstract
The p20 protein encoded by the Citrus Tristeza Virus (CTV) was previously identified as a RNA silencing suppressor. In this study, we analyzed the p20’s suppressing activity from five phylogenetic groups of CTV, using the co-infiltration assay of Green fluorescence protein (GFP) gene and the suppressor gene in 16C line Nicotiana benthamiana plants. Green fluorescence, GFP mRNA relative levels and GFP specific siRNAS were compared showing in most cases, only slight differences. Contrary to previous studies, the p20 suppressor was not able to impede neither short range nor systemic spreading of RNA silencing. The suppressor from the phylogenetic group 4 revealed a much reduced activity when compared with the others. At present we still don’t know whether this property is a characteristic of this group or an atypical feature due to a unique point mutation. The differences in the symptom type and intensity originated by isolates belonging to the phylogenetic groups assayed could not be related to differences to the p20 suppressor’s activity.
Similar content being viewed by others
References
Albiach-Marti, M. R., Robertson, C., Gowda, S., Tatineni, S., Belliure, B., Garnsey, S. M., et al. (2010). The pathogenicity determinant of Citrus tristeza virus causing the seedling yellows syndrome maps at the 3′-terminal region of the viral genome. Molecular Plant Pathology, 11(1), 55–67.
Baulcombe, D. (2004). RNA silencing in plants. Nature, 431, 356–363.
Brigneti, G., Voinnet, O., Li, W. X., Ji, L. H., Ding, S. W., & Baulcombe, D. C. (1998). Viral pathogenicity determinants are suppressors of transgene silencing in Nicotiana benthamiana. EMBO Journal, 17(22), 6739–6746.
Brodersen, P., & Voinnet, O. (2006). The diversity of RNA silencing pathways in plants. Trends in Genetics, 22(5), 268–280.
Chen, H. Y., Yang, J., Lin, C., & Yuan, Y. A. (2008). Structural basis for RNA-silencing suppression by Tomato aspermy virus protein 2b. EMBO Reports, 9(8), 754–760.
Diaz-Pendon, J. A., & Ding, S. W. (2008). Direct and indirect roles of viral suppressors of RNA silencing in pathogenesis. Annual Review of Phytopathology, 46, 303–326.
Gowda, S., Satyanarayana, T., Davis, C. L., Navas-Castillo, J., Albiach-Marti, M. R., Mawassi, M., et al. (2000). The p20 gene product of Citrus tristeza virus accumulates in the amorphous inclusion bodies. Virology, 274(2), 246–254.
Haseloff, J., Siemering, K. R., Prasher, D. C., & Hodge, S. (1997). Removal of a cryptic intron and subcellular localization of green fluorescent protein are required to mark transgenic Arabidopsis plants brightly. Proceedings of the National Academy of Sciences of U S A, 94(6), 2122–2127.
Himber, C., Dunoyer, P., Moissiard, G., Ritzenthaler, C., & Voinnet, O. (2003). Transitivity-dependent and -independent cell-to-cell movement of RNA silencing. EMBO Journal, 22(17), 4523–4533.
Karasev, A. V., Boyko, V. P., Gowda, S., Nikolaeva, O. V., Hilf, M. E., Koonin, E. V., et al. (1995). Complete sequence of the Citrus tristeza virus-RNA genome. Virology, 208(2), 511–520.
Karimi, M., Inze, D., & Depicker, A. (2002). GATEWAY vectors for Agrobacterium-mediated plant transformation. Trends in Plant Science, 7(5), 193–195.
Li, F., & Ding, S. W. (2006). Virus counterdefense: diverse strategies for evading the RNA-silencing immunity. Annual Review of Microbiology, 60, 503–531.
Liang, D., Finnegan, E. J., Dennis, E. S., Waterhouse, P. M., & Wang, M.-B. (2011). Mobile silencing in plants: what is the signal and what defines the target. Frontiers in Biology, 6(2), 140–146.
Lu, R., Folimonov, A., Shintaku, M., Li, W. X., Falk, B. W., Dawson, W. O., et al. (2004). Three distinct suppressors of RNA silencing encoded by a 20-kb viral RNA genome. Proceedings of the National Academy of Sciences of United States of America, 101(44), 15742–15747.
Moreno, P., Ambros, S., Albiach-Marti, M. R., Guerri, J., & Pena, L. (2008). Citrus tristeza virus: a pathogen that changed the course of the citrus industry. Molecular Plant Pathology, 9, 251–268.
Niblett, C. L., Genc, H., Cevik, B., Halbert, S., Brown, L., Nolasco, G., et al. (2000). Progress on strain differentiation of Citrus tristeza virus and its application to the epidemiology of citrus tristeza disease. Virus Research, 71(1–2), 97–106.
Nolasco, G., Santos, C., Silva, G., & Fonseca, F. (2009). Development of an asymmetric PCR-ELISA typing method for Citrus tristeza virus based on the coat protein gene. Journal of Virology Methods, 155(2), 97–108.
Pall, G. S., Codony-Servat, C., Byrne, J., Ritchie, L., & Hamilton, A. (2007). Carbodiimide-mediated cross-linking of RNA to nylon membranes improves the detection of siRNA, miRNA and piRNA by northern blot. Nucleic Acids Research, 35(8), e60.
Pfaffl, M. W. (2001). A new mathematical model for relative quantification in real-time RT-PCR. Nucleic Acids Research, 29(9), e45.
Reed, J. C., Kasschau, K. D., Prokhnevsky, A. I., Gopinath, K., Pogue, G. P., Carrington, J. C., et al. (2003). Suppressor of RNA silencing encoded by Beet yellows virus. Virology, 306(2), 203–209.
Roistacher, C. N., & Moreno, P. (1991). The worldwide threat from destructive isolates of Citrus tristeza virus. A review. Proceedings of the 11th Conference of the International Organization of Citrus Virologists. Riverside, 7–19.
Rotenberg, D., Thompson, T. S., German, T. L., & Willis, D. K. (2006). Methods for effective real-time RT-PCR analysis of virus-induced gene silencing. Journal of Virology Methods, 138(1–2), 49–59.
Ruiz, M. T., Voinnet, O., & Baulcombe, D. C. (1998). Initiation and maintenance of virus-induced gene silencing. The Plant Cell, 10(6), 937–946.
Satyanarayana, T., Gowda, S., Boyko, V. P., Albiach-Marti, M. R., Mawassi, M., Navas-Castillo, J., et al. (1999). An engineered closterovirus RNA replicon and analysis of heterologous terminal sequences for replication. Proceedings of the National Academy of Sciences of United States of America, 96(13), 7433–7438.
Torres-Barcelo, C., Martin, S., Daros, J. A., & Elena, S. F. (2008). From hypo- to hypersuppression: effect of amino acid substitutions on the RNA-silencing suppressor activity of the Tobacco etch potyvirus HC-Pro. Genetics, 180(2), 1039–1049.
Voinnet, O., Pinto, Y. M., & Baulcombe, D. C. (1999). Suppression of gene silencing: a general strategy used by diverse DNA and RNA viruses of plants. Proceedings of the National Academy of Sciences of United States of America, 96(24), 14147–14152.
Acknowledgements
This research was funded by grant PTDC/AGR-GPL/99512/2008 from Foundation for Science and Technology, Portugal. Angela Costa and Gonçalo Silva are the recipients of FCT grants SFRH/BD/62248/2009 and SFRH/BD/37310/2007, respectively.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Marques, N.T., Costa, Â.A., Lopes, D. et al. Comparing p20’s RNA silencing suppressing activity among five phylogenetic groups of Citrus Tristeza virus . Eur J Plant Pathol 133, 229–235 (2012). https://doi.org/10.1007/s10658-011-9877-0
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10658-011-9877-0