American Journal of Potato Research

, Volume 87, Issue 1, pp 1–9 | Cite as

Serological Properties of Ordinary and Necrotic Isolates of Potato virus Y: A Case Study of PVYN Misidentification

  • Alexander V. Karasev
  • Olga V. Nikolaeva
  • Xiaojun Hu
  • Zachary Sielaff
  • Jonathan Whitworth
  • James H. Lorenzen
  • Stewart M. GrayEmail author


In the course of a multi-year survey of Potato virus Y (PVY) incidence and diversity in the U.S. seed potato crop, an unusual PVY variant was identified in low but significant levels in multiple states. This variant, PVYO-O5, was initially detected by a commercially available PVYN-specific monoclonal antibody, 1F5. This antibody is widely used by U.S. Seed Certification programs to test for PVYN and is one of two antibodies designated by the North American Plant Protection Organization (NAPPO) for pre-shipment testing of tuber lots that are to be transported between countries. Consequently, PVYN positives identified by the 1F5 antibody have triggered quarantine actions, prevented cross-border shipments and impacted trade. Here, we demonstrate by a variety of methods that the PVYO-O5 is a variant within the ordinary PVY strain (PVYO). Specifically, the PVYO-O5 variant likely arose due to a single amino acid substitution within the capsid protein. This variant does not induce vein necrosis in tobacco or tuber necrosis in susceptible varieties of potato. Furthermore, it is identified by RT-PCR based diagnostics as PVYO and it has a typical PVYO genome sequence. We demonstrate that another PVYN specific monoclonal antibody, SASA-N, recognizes an epitope distinct from that recognized by 1F5, and correctly identifies the PVYO-O5 variants as belonging to the PVYO serotype. Since the PVYO-O5 variant is present in many seed producing states and misidentification of PVYO-O5 as PVYN/NTN has clear quarantine implications for export shipments of potato, the limitations of the commercially available monoclonal antibodies should be considered in any certification or phytosanitary testing program.


Capsid Protein Single Amino Acid Substitution Conformational Epitope Necrotic Strain Potato Tuber Necrotic Ringspot Disease 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


A lo largo del estudio de varios años sobre la incidencia y diversidad del virus Y de la papa (PVY) en los cultivos de papa para semilla en los Estados Unidos (EU), se identificó a una variante inusual a niveles bajos pero significativos en múltiples estados. Esta variante, PVYO-O5, se detectó inicialmente con un anticuerpo monoclonal comercialmente disponible específico para PVYN, el 1F5. Este anticuerpo es ampliamente usado por los Programas de Certificación de Semilla en los EU para PVYN, y es uno de los dos anticuerpos designados por la Organización Norteamericana de Protección de Plantas (NAPPO) para pruebas de pre-envío de lotes de tubérculos que serán transportados entre países. Consecuentemente, los PVYN positivos identificados con el anticuerpo 1F5 han disparado acciones cuarentenarias, evitando envíos trans-fronteras y han impactado al comercio. Aquí, nosotros demostramos con diversos métodos que PVYO-O5 es una variante del PVY ordinario (PVYO). Específicamente, la variante PVYO-O5 es probable que haya surgido debido a una substitución de un aminoácido dentro de la proteína de la cápside. Esta variante no induce necrosis de las venas en tabaco o necrosis del tubérculo en variedades susceptibles de papa. Aún mas, se le identifica como PVYO mediante RT-PCR y tiene la típica secuencia genómica del PVYO. Demostramos que otro anticuerpo monoclonal específico para PVYN, el SASA-N, reconoce un epítope distinto al reconocido por 1F5, e identifica correctamente a las variantes PVYO-O5 como pertenecientes al serotipo PVYO. Tomando en cuenta que la variante PVYO-O5 esta presente en muchos estados que producen semilla, y que la identificación equivocada de PVYO-O5 como PVYN/NTN tiene claras implicaciones cuarentenarias para envíos de exportación de papa, se deberían de considerar las limitaciones de los anticuerpos monoclonales disponibles comercialmente en cualquier programa de pruebas para certificación o fitosanidad.



This work was funded in part by the USDA-CSREES-NRICGP (#2009-35600-05025), USDA-APHIS, the National Potato Council, USDA-ARS Cooperative Agreements 58-5354-7-540 and 58-1907-8-870, and the Idaho Potato Commission. We thank Dawn Smith, Teresa Meacham, and Cheryl Seidel for their assistance with greenhouse and laboratory assays.


  1. Ali, M.C., T. Maoka, and K.T. Natsuaki. 2007. A point mutation changes the serotype of a potato virus Y isolate; genomic determination of the serotype of PVY strains. Virus Genes 35: 359–367.CrossRefGoogle Scholar
  2. Anonymous. 2003. Requirements for importation of potatoes in a NAPPO member country. North American Plant Protection Organization.Google Scholar
  3. Baldauf, P.M., S.M. Gray, and K.L. Perry. 2006. Biological and serological properties of potato virus Y isolates in northeastern United States potato. Plant Disease 90: 559–566.CrossRefGoogle Scholar
  4. Beczner, L., J. Horvath, I. Romhanyi, and H. Forster. 1984. Studies on the etiology of tuber necrotic ringspot disease in potato. Potato Research 27: 339–352.CrossRefGoogle Scholar
  5. BlancoUrgoiti, B., F. Sanchez, J. Dopazo, and F. Ponz. 1996. A strain-type clustering of potato virus Y based on the genetic distance between isolates calculated by RFLP analysis of the amplified coat protein gene. Archives of Virology 141: 2425–2442.CrossRefGoogle Scholar
  6. Clark, M.F. and A.N. Adams. 1977. Characteristics of microplate method of enzyme-linked immunosorbent assay for detection of plant viruses. Journal of General Virology 34: 475–483.CrossRefPubMedGoogle Scholar
  7. Crosslin, J.M., P.B. Hamm, D.C. Hane, J. Jaeger, C.R. Brown, P.J. Shiel, P.H. Berger, and R.E. Thornton. 2006. The occurrence of PVYO, PVYN, and PVYN: O strains of potato virus Y in certified potato seed lot trials in Washington and Oregon. Plant Disease 90: 1102–1105.CrossRefGoogle Scholar
  8. Crosslin, J.M., P.B. Hamm, P.J. Shiel, D.C. Hane, C.R. Brown, and P.H. Berger. 2005. Serological and molecular detection of tobacco veinal necrosis isolates of potato virus Y (PVYN) from potatoes grown in the western United States. American Journal of Potato Research 82: 263–269.CrossRefGoogle Scholar
  9. Ellis, P., R. StaceSmith, G. Bowler, and D.J. Mackenzie. 1996. Production of monoclonal antibodies for detection and identification of strains of potato virus Y. Canadian Journal of Plant Pathology 18: 64–70.Google Scholar
  10. Ellis, P., R. StaceSmith, and G. deVilliers. 1997. Identification and geographic distribution of serotypes of potato virus Y. Plant Disease 81: 481–484.CrossRefGoogle Scholar
  11. Gray, S., A. Karasev, J. Lorenzen, J. Whitworth, P. Nolte, and K. Perry. 2008. Emerging diversity in potato virus Y poses new challenges for the US potato industry. Phytopathology 98: S61–S61.Google Scholar
  12. Hu, X., T. Meacham, L. Ewing, S. Gray, and A. Karasev. 2009. A novel recombinant strain of potato virus Y allows identification of a new viral genetic determinant of vein necrosis in tobacco. Virus Research 143: 68–76.CrossRefPubMedGoogle Scholar
  13. Kahn, R.P. and R.L. Monroe. 1963. Detection of tobacco veinal necrosis strain of potato virus Y in Solanum cardenasii and S. andigenum introduced into United States. Phytopathology 53: 1356–1359.Google Scholar
  14. Karasev, A.V., T. Meacham, X. Hu, J. Whitworth, S.M. Gray, N. Olsen, and P. Nolte. 2008. Identification of potato virus Y strains associated with tuber damage during a recent virus outbreak in potato in Idaho. Plant Disease 92: 1371–1371.CrossRefGoogle Scholar
  15. Lorenzen, J.H., T. Meacham, P.H. Berger, P.J. Shiel, J.M. Crosslin, P.B. Hamm, and H. Kopp. 2006a. Whole genome characterization of potato virus Y isolates collected in the western USA and their comparison to isolates from Europe and Canada. Archives of Virology 151: 1055–1074.CrossRefPubMedGoogle Scholar
  16. Lorenzen, J.H., L.M. Piche, N.C. Gudmestad, T. Meacham, and P. Shiel. 2006b. A multiplex PCR assay to characterize potato virus Y isolates and identify strain mixtures. Plant Disease 90: 935–940.CrossRefGoogle Scholar
  17. McDonald, J.G. and G.T. Kristjansson. 1993. Properties of strains of potato virus-Y(N) in North-America. Plant Disease 77: 87–89.Google Scholar
  18. Nie, X. and R.P. Singh. 2003. Evolution of North American PVYNTN strain Tu 660 from local PVYN by mutation rather than recombination. Virus Genes 26: 39–47.CrossRefPubMedGoogle Scholar
  19. Nie, X., R.P. Singh, and M. Singh. 2004. Molecular and pathological characterization of N: O isolates of the potato virus Y from Manitoba, Canada. Canadian Journal of Plant Pathology 26: 573–583.Google Scholar
  20. Nikolaeva, O.V., A.V. Karasev, C.A. Powell, S.M. Garnsey, and R.F. Lee. 1997. Modulation of the antigenic reactivity of the citrus tristeza virus coat protein. Journal of Immunological Methods 206: 97–105.CrossRefPubMedGoogle Scholar
  21. Piche, L.M., R.P. Singh, X. Nie, and N.C. Gudmestad. 2004. Diversity among potato virus Y isolates obtained from potatoes grown in the United States. Phytopathology 94: 1368–1375.CrossRefPubMedGoogle Scholar
  22. Rose, D.G. and A.L. Hubbard. 1986. Production of monoclonal antibodies for the detection of potato virus Y. Annals of Applied Biology 109: 317–321.CrossRefGoogle Scholar
  23. Singh, R.P., J.P.T. Valkonen, S.M. Gray, N. Boonham, R.A.C. Jones, C. Kerlan, and J. Schubert. 2008. Discussion paper: The naming of potato virus Y strains infecting potato. Archives of Virology 153: 1–13.CrossRefPubMedGoogle Scholar
  24. Xu, H. 2008. Molecular detection and identification of tobacco veinal necrosis and potato tuber necrosis strains of potato virus Y in tobacco samples. Canadian Journal of Plant Pathology 30: 380–380.Google Scholar
  25. Xu, H., J. Nie, and S.H. De Boer. 2005. Differentiation and molecular detection of Canadian necrotic strains of potato virus Y. Canadian Journal of Plant Pathology 27: 125–131.Google Scholar

Copyright information

© Potato Association of America 2009

Authors and Affiliations

  • Alexander V. Karasev
    • 1
  • Olga V. Nikolaeva
    • 1
  • Xiaojun Hu
    • 1
  • Zachary Sielaff
    • 1
  • Jonathan Whitworth
    • 2
  • James H. Lorenzen
    • 1
  • Stewart M. Gray
    • 3
    Email author
  1. 1.Department of PSESUniversity of IdahoMoscowUSA
  2. 2.USDA-ARSAberdeenUSA
  3. 3.USDA-ARSCornell UniversityIthacaUSA

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