Determination of the Dominant Variants of Hop Stunt Viroid in Two Different Cachexia Isolates from North and South of Iran

Authors
1 College of Agriculture, Islamic Azad University, Varamin Branch, Varamin, Islamic Republic of Iran.
2 Horticultural Science Research Institute, Citrus and Subtropical Fruits Research Center, AREEO, Ramsar, Islamic Republic of Iran.
Abstract
Citrus plants are hosts of several viroid species, among which, pathogenic variants of Hop Stunt Viroid (HSVd) induce citrus cachexia disease. Stunting, chlorosis, gumming of the bark, stem pitting and decline are symptoms of cachexia in mandarins and their hybrids as susceptible hosts. Based on the pathogenic properties on citrus, HSVd variants are divided in two distinct groups: those that are symptomless on sensitive citrus host species and those that induce cachexia disease. In this study, two cachexia isolates were selected and biological indexing was performed in a controlled temperature greenhouse (40ºC day and 28ºC night) using Etrog citron (Citrus medica) grafted on Rough lemon (C. jhambiri), as a common indicator for citrus viroids. The plants were inoculated with the inocula from a severe symptomatic tree of a newly declining orchard of Jiroft, Kerman province and a mild symptomatic tree from Mazandaran province. Presence of HSVd was confirmed with sPAGE, Hybridization by DIG-labeled probes and RT-PCR using specific primers of HSVd. Primary and secondary structures of the isolates were studied. The consensus sequence of RT-PCR amplicons of the severe isolate (JX430796) presented 97% identity with the reference sequence of a IIb variant of HSVd (AF213501) and an Iranian isolate of the viroid (GQ923783) deposited in the gene bank. The mild isolate (JX430798) presented 100% homology with the HSVd-IIc variant previously reported from Iran (GQ923784). Both isolates were shown to be cachexia inducing according to their sizes, sequences and lack of “non-cachexia expression motif” structures.

Keywords


1. Amiri Mazhar, M., Bagherian, S. A., Salahi Ardakani, A. A. and Izadpanah, K. 2014. Nucleotide Sequence and Structural Features of Hop Stunt Viroid and Citrus Bent Leaf Viroid Variants from Blighted Citrus Plants in Kohgiluyeh–Boyerahmad Province of Iran. J. Agr. Sci. Tech., 16: 657-665.
2. Banihashemian, S. N. and Bani Hashemian, S. M. 2012. Preliminary Study of a Decline Inducing Isolate of Cachexia Citrus by Indicator Plants and RT-PCR. Iran. J. App. Plant Protec., 1: 127-138.
3. Banihashemian, S. N., Bani Hashemian, S. M., Ashkan, S. M. and Ebrahimi-Moghaddam, L. 2012. Application of Molecular Techniques in Study of the Hop Stunt Viroid Variants in Citrus by RT-PCR, sPAGE and Hybridization Techniques. The 6th Iranian Cong. of Virol., Tehran, Iran, 76 PP.
4. Bani Hashemian, S. M., Taheri, H., Mohammad Alian, Y., Bové, J. M. and Duran-Vila, N. 2013. Complex Mixtures of Viroids Identification in the Two Main Citrus Growing Areas of Iran. J. Plant Pathol., 95: 647-654.
5. Bani Hashemian, S. M., Pensabene-Bellavia, G., Duran-Vila, N. and Serra, P. 2015. Phloem Restriction of Viroids in Three Citrus Hosts is Overcome by Grafting with Etrog Citron: Potential Involvement of a Translocatable Factor. J. Gen. Virol., 96(8): 2405-10.
6. Bernad, L. and Duran-Vila, N. 2006. A Novel RT-PCR Approach for Detection and Characterization of Citrus Viroids. Mol. Cell. Probe., 20: 105-113.
7. Childs, J. F., 1950. The Cachexia Disease of Orlando Tangelo. Plant Dis. Rep., 34: 295-298.
8. Duran-Vila, N., Roistacher, C. N., Rivera-Bustamante, R. and Semancik, J. S. 1988. A Definition of Citrus Viroid Groups and Their Relationship to the Exocortis Disease. J. Gen. Virol., 69: 3069-3080.
9. Duran-Vila, N., Pina, J. A. and Navarro, L. 1993. Improved Indexing of Citrus Viroids. Proceedings of the 12th Conference of the International Organization Citrus Virologists (IOCV), Riverside, CA, USA, PP202-211.
10. Duran-Vila, N., Semancik, J. S. and Broadbent, P. 2000. Viroid Diseases, Cachexia and Exocortis. In: “Compendium of Citrus Diseases”, (Eds.): Timmer, L. W., Garnsey, S. M. and Graham, J. H.. 2nd Edition, APS, St. Paul, MN, PP. 51–54.
11. Eiras, M., Silva, S. R., Stuchi, E. S., Carvalho, S. A. and Garcez, R. M. 2013. Identification and Characterization of Viroids in ‘Navelina ISA 315’ Sweet Orange. Tropical Plant Pathol., 38: 58-62.
12. Flores, R., Hernández, C., Martínez de Alba, E., Daròs, J. A. and Di Serio, F. 2005. Viroids and Viroid-host Interactions. Annu. Rev. Phytopathol., 43: 117–139.
13. Habashi, M.and Rahimian, H. 1984. Xyloporosis in Iran. Scientific J. Agric., 10: 27.
14. Igloi, G. L. 1983. Silver Stain for the Detection of Nanogram Amounts of tRNA Following Two Dimensional Electrophoresis. Anal. Biochem., 134: 184-188.
15. Keese, P. and Symons, R. H. 1985. Domains in Viroids: Evidence of Intermolecular RNA Rearrangements and Their Contribution to Viroid Evolution. Proc. Natl. Acad. Sci., 82: 4582–4586.
16. King, A. M. Q., Adams, M. J., Carstens, E. B. and Lefkowitz, E. J. 2012. Virus Taxonomy Classification and Nomenclature of Viruses Ninth Report of the International Committee on Taxonomy of Viruses. International :union: of Microbiological Societies Virology Division. Academic Press, USA, 1327 PP.
17. Levy, L. and Hadidi, A. 1993. Direct Nucleotide Sequencing of PCR-amplified DNAs of the Closely Related Citrus Viroids IIa and IIb (Cachexia). In: “Proceedings of the 12th Conference of the International Organization Citrus Virologists (IOCV)”, (Eds.): Moreno, P., da Graça, J. V. and Timmer, L. W.. Riverside, CA, USA, PP.180–186.
18. Loconsole, G., Önelge, N., Yokomi, R. K., Kubaa, R. A., Savino, V. and Saponari, M. 2013. Rapid Differentiation of Citrus Hop Stunt Viroid Variants by Real-Time RT-PCR and High Resolution Melting Analysis. Mol. Cell. Probe., 27: 221-229.
19. Mohamed, M. E., Bani Hashemian, S. M., Dafalla, G., Bové , J. M. and Duran-Vila, N. 2009. Occurrence and Identification of Citrus Viroids from Sudan. J. Plant Pathol., 91: 185-190.
20. Murcia, N., Serra, P., Olmos, A. and Duran-Vila, N. 2009. A Novel Hybridization Approach for Detection of Citrus Viroids. Mol. Cell. Probe., 23: 25-102.
21. Palacio-Bielsa, A., Romero-Durbán, J. and Duran-Vila, N. 2004. Characterization of Citrus HSVd Isolates. Arch. Virol., 149: 537–552.
22. Pina, J. A., Duran-Vila, N. and Navarro, L. 1991. Interference of Citrus Viroids with Cachexia Symptoms on Parson’s Special Mandarin. Proceedings of the 11th Conference of the International Organization Citrus Virologists (IOCV), Riverside, CA,USA, PP. 206-208.
23. Puchta, H., Ramm, K., Luckinger, R., Hadas, R., Bar-Joseph, M. and Sänger, H. L. 1991. Primary and Secondary Structure of Citrus Viroid IV (CVd IV), a New Chimeric Viroid Present in Dwarfed Grapefruit in Israel. Nucleic Acids Res., 19: 6640.
24. Reanwarakorn, K. and Semancik, J. S. 1998. Regulation of Pathogenicity in Hop Stunt Viroid Related Group II Citrus Viroids. J. Gen. Virol., 79: 3163–3171.
25. Rivera-Bustamante, R. F., Gin, R. and Semancik, J. S. 1986. Enhanced Resolution of Circular and Linear Molecular Forms of Viroid and Viroid-like RNA by Electrophoresis in a Discontinuous-pH System. Anal. Biochem., 156: 91-95.
26. Roistacher, C. N. 1991. Graft–transmissible Diaease of Citrus. Handbook for Detection and Diagnosis. FAO Publications. 286 PP.
27. Sano, T., Hataya, T. and Shikata, E. 1988. Complete Nucleotide Sequence of a Viroid Isolate from Etrog Citron, a New Member of Hop Stunt Viroid Group. Nucleic Acid. Res., 16: 347.
28. Semancik, J. S., Roistacher, C. N., Rivera-Bustamante, R. F. and Duran-Vila, N. 1988. Citrus Cachexia Viroid, a New Viroid of Citrus: Relationship to Viroids of the Exocortis Disease Complex. J. Gen. Virol., 69: 3059-3068.
29. Serra, P., Gago, S. and Duran-Vila, N. 2008. A Single Nucleotide Change in Hop Stunt Viroid Modulates Citrus Cachexia Symptoms. Virus Res., 138: 130-134.
30. Thompson, J. D., Higgins, D. G. and Gibson, T. J. 1994. CLUSTAL W. Improving the Sensitivity of Progressive Multiple Sequences Alignment through Sequence Weighting, Positions Specific Gap Penalties and Weight Matrix Choice. Nucleic Acid. Res., 22: 4673-4680.