عنوان مقاله [English]
Citrus exocortis viroid (CEVd) is the causal agent of exocortis disease, the economically important viroid disease of citrus. In this research, sequence polymorphism and population structure of CEVd were investigated in CEVd tolerant and sensitive hosts (sour orange (Citrus aurantium L.) and citrange (Poncirus trifoliata (L.) Raf. × C. sinensis (L.), respectively) seedlings. Full-length in vitro transcript of single sequence CEVd-S1 isolate was used for mechanical inoculation. The genetic diversity of CEVd populations was estimated in two citrus hosts by single-strand conformation polymorphism (SSCP) and sequencing. The analysis of cloned DNAs recovered from infected hosts by this isolate demonstrated that host species was effective on the variability within a single CEVd isolate. The amount and composition of the genetic diversity were different among the two hosts, and was higher in the tolerant host compared with the sensitive one. Furthermore, the analysis of thermodynamic secondary structures illustrated that nucleotide changes identified in this study did not induce major modifications in the viroid rod-like secondary structure.
10. Fawcett, H. S. & Klotz, J. (1948). Exocortis of trifoliate orange. California Agriculture, 2(10) 13.
11. Flores, R., Daros, J. A. & Navarro, J. A. (2003). Replication. In: A. Hadidi, R. Flores, J. W. Randles & J. S. Semancik.(Ed.), Viroids. (pp. 55-60). CSIRO Publishing
12. Gandia, M., Bernad, L., Rubio, L. & Duran-Vila, N. (2007). Host effect on the molecular and biological properties of a Citrus exocortis viroid isolate from Vicia faba. Phytopathology, 97(80), 1004-1010.
13. Gandia, M., Palacio, A. & Duran-Vila, N. (2000). Variability of Citrus exocortis viroid (CEVd). In: Proceedings of International Organization of Citrus Virologists Conference Proceedings, 1 Jan., University of California, Riverside, California, pp. 265-272.
14. Garcia-Arenal, F., Fraile, A. & Malpica, J.M. (2003). Variation and evolution of plant virus populations. International Microbiology, 6(4), 225-232.
15. Garnsey, S. M. & Jones, J. W. (1967). Mechanical transmission of exocortis virus with contaminated budding tools. Plant Disease, 51, 410-413.
16. Ghobakhloo, M., Dizadji, A. & Yamchi, A. (2016). Infectivity of in vitro- transcribed Citrus exocortis viroid (CEVd) on citrange. In: Proceedings of 22nd Iranian Plant Protection Congress, 27-30 August, University of Tehran, Alborz, Iran, pp 50.
17. Gomez, G. & Pallas, V. (2007). Mature monomeric forms of Hop stunt viroid resist RNA silencing in transgenic plants. The Plant Journal, 51(6), 1041-1049.
18. Gozmanova, M., Denti, M. A., Minkov, I. N., Tsagris, M. & Tabler, M. (2003). Characterization of the RNA motif responsible for the specific interaction of Potato spindle tuber viroid RNA (PSTVd) and the tomato protein Virp1. Nucleic Acids Research, 31(19), 5534-5543.
19. Habashi, M. (1988). Survey of citrus exocortis disease in northern of Iran. Project Annual Report. Plant Pests and Diseases Research Laboratory of Mazandaran.
20. Hadidi, A., Flores, R., Randles, J. & Semancik, J. (2003). Viroids. CSIRO Publishing.
21. Hadidi, A., Vidalakis, G. & Sano, T. (2017). Economic significance of fruit tree and grapevine viroids. In: A. Hadidi, R. Flores, J. Randles & P. Palukaitis (Ed), Viroids and Satellites. (pp. 15-25). Academic Press.
22. Hajeri, S. (2010). Study of Molecular and Biological Properties of Citrus exocortis viroid and Dweet mottle virus. Ph. D. dissertation, UC Riverside.
23. Hajeri, S., Ramadugu, C., Manjunath, K., Ng, J., Lee, R. & Vidalakis, G. (2011). In vivo generated Citrus exocortis viroid progeny variants display a range of phenotypes with altered levels of replication, systemic accumulation and pathogenicity. Virology, 417(2), 400-409.
24. Hall, T. A. (1999). BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series,41(41), 95-98.
25. Librado, P. & Rozas, J. (2009). DnaSP v5: A software for comprehensive analysis of DNA polymorphism data. Bioinformatics, 25(11), 1451-1452.
26. Lin, C. Y., Wu, M. L., Shen, T. L., Yeh, H. H. & Hung, T. H. (2015). Multiplex detection, distribution, and genetic diversity of Hop stunt viroid and Citrus exocortis viroid infecting citrus in Taiwan. Virology Journal,12(1), 11.
27. Matousek, J., Orctova, L., Ptaek, J., Patzak, J., Dedic, P., Steger, G. & Riesner, D. (2007). Experimental transmission of Pospiviroid populations to weed species characteristic of potato and hop fields. Journal of virology, 81(21), 11891-11899.
28. Matzura, O. & Wennborg, A. (1996). RNAdraw: An integrated program for RNA secondary structure calculation and analysis under 32-bit Microsoft Windows. Computer applications in the biosciences, 12(3), 247-249.
29. Murica, N., Bernad, L., Duran-Vila, N. & Serra, P. (2011). Two nucleotide positions in the Citrus exocortis viroid RNA associated with symptom expression in Etrog citron but not in experimental herbaceous hosts. Molecular Plant Pathology, 12(2), 203-208.
30. Nie, X. (2012). Analysis of sequence polymorphism and population structure of Tomato chlorotic dwarf viroid and Potato spindle tuber viroid in viroid-infected tomato plants. Viruses, 4(6),940-953.
31. Qi, Y. & Ding, B. (2003). Inhibition of cell growth and shoot development by a specific nucleotide sequence in a noncoding viroid RNA. Plant Cell, 15(60), 1360-1374.
32. Roossinck, M. J. (2008). Plant virus evolution. Springer-Verlag.
33. Sambrook, J. & Russell, D. (2001). Molecular Cloning: A Laboratory Manual. (3rd ed.). New York, USA: Cold Spring Harbor Laboratory Press.
34. Semancik, J. S., Szychowski, J. A., Rakowski, A. G. & Symons, R. H. (1993). Isolates of citrus exocortis viroid recovered by host and tissue selection. Journal of General Virology, 74(11), 2427-2436.
35. Szychowski, J. A., Vidalakis, G. & Semancik, J. S. (2005). Host-directed processing of Citrus exocortis viroid. Journal of General Virology, 86(2), 473-477.
36. Tamura, K., Stecher, G., Peterson, D., Filipski, A. & Kumar, S. (2013). MEGA6: molecular evolutionary genetics analysis version 6.0. Molecular Biology and Evolution, 30(12), 2725-2729.
37. Visvader, J. E. & Symons, R. H. (1985). Eleven new sequence variants of Citrus exocortis viroid and the correlation of sequence with pathogenicity. Nucleic Acids Research, 13(80), 2907-2920.
38. Zhu, Y., Qi, Y., Xun, Y., Owens, R. & Ding, B. (2002). Movement of potato spindle tuber viroid reveals regulatory points of phloem-mediated RNA traffic. Plant Physiology, 130(1), 138-146.