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Descriptions and Lists from the VIDE Database

Odontoglossum ringspot tobamovirus

Index

• Nomenclature
• Host range, transmission and symptoms
• Physical and biochemical properties
• Taxonomy and relationships
• Comments and References

Data collated by D.-E. Lesemann and P. Beetham, 1986.

Nomenclature

Synonyms

tobacco mosaic virus - orchid strain (Jensen and Gold, 1951; Kado et al., 1968).

Acronym

ORSV

ICTV decimal code

71.0.1.0.005

Host range and symptoms

Natural host range and symptoms

• Odontoglossum grande - ringspots.
• Cymbidium spp. - `diamond' mottle.
  More than 20 genera of orchids are reported to be infected by odontoglossum ringspot virus and show flower colour-breaking, chlorotic streaking, mosaic or necrosis. Symptomless in some cultivars.

Transmission

Transmitted by means not involving a vector. Virus transmitted by mechanical inoculation.

Geographical distribution

Probably distributed worldwide.

Experimental host range

Several (3-9) families susceptible.

Diagnostically susceptible host species and symptoms

• Nicotiana tabacum cv. Xanthi-nc - necrotic local lesions in older leaves, ring-like local lesions in younger leaves.
• Cassia occidentalis, Chenopodium amaranticolor - pinpoint necrotic spots.
  The symptoms induced in orchids are not diagnostic.

Maintenance and propagation hosts

Nicotiana tabacum cv. Samsun, Nicotiana clevelandii.

Assay hosts (Local lesions or Whole plants)

Chenopodium quinoa (L), Nicotiana tabacum cv. Xanthi-nc (L).

Susceptible host species

• Beta vulgaris
• Cassia occidentalis
• Chenopodium amaranticolor
• Chenopodium quinoa
• Cymbidium alexanderi
• Gomphrena globosa
• Nicotiana clevelandii
• Nicotiana glutinosa
• Nicotiana tabacum
• Odontoglossum grande
• Tetragonia tetragonioides
• Zinnia elegans

Families containing susceptible hosts

• Amaranthaceae (1/1)
• Chenopodiaceae (3/3)
• Compositae (1/1)
• Leguminosae-Caesalpinioideae (1/1)
• Orchidaceae (2/2)
• Solanaceae (3/3)
• Tetragoniaceae (1/1)

Sources of host-range data

Paul et al. (1965); Lawson and Ali (1975).

Physical and biochemical properties

Properties of particles in sap

TIP: 90 °C. DEP: log₁₀ minus 6. Infectivity of sap not changed by treatment with di-ethyl ether. Leaf sap contains many virions.

Particle morphology

Virions rod-shaped; not enveloped; usually straight; with a clear modal length; of mostly 300 nm (but also shorter, broken virions); 18 nm wide. Axial canal obvious.

Physical properties

Two sedimenting components in purified preparations; sedimentation coefficient of the longer virions 212 S; of the other(s) 119 S (of the shorter virions). Density 1.25 g cm^-3 in CsCl (unfixed). A₂₆₀/A₂₈₀ ratio 0.99 (for predominantly longer virions), or 0.63 (for the shorter virions; both values corrected for scattering).

Biochemical properties

Virions contain 5 % nucleic acid.

NCBI sequence data (Entrez search)

Sequence database accession code(s)

• X55295 Em(40)_vi:TOORCOAT Gb(84)_vi:TOORCOAT Odontoglossum ringspot virus coat protein gene. 12/91 891bp.
• X55296 Em(40)_vi:ORVTRANS Gb(84)_vi:ORVTRANS Odontoglossum ringspot virus cell-to-cell transport gene. 12/90 912bp.
• X80053 Gb(84)_vi:ORSPVCY Odontoglossum ringspot Virus-Cy RNA. 7/94 1,015bp.
• X78966 Em(43)_vi:Orsvcp Gb(89)n:Orsvcp Odontoglossum Ringspot Virus (strain Cy) coat protein mRNA. 5/95 900bp.
• X82130 Em(43)_vi:Orsvrna Gb(89)_vi:Orsvrna Odontoglossum ringspot virus RNA for replicase, movement protein and coat protein genes. 10/9.

Features of proteins

Virion protein(s) one; M_r 17598; coat protein. Method of preparation: Paul and Buchta (1971); Henning (1972). Amino acid composition: Henning (1972).

Cytopathology

Virions found in mesophyll, epidermis and vascular parenchyma; in chloroplasts and in cytoplasm (very occasionally). Inclusions present in infected cells; are crystals in the cytoplasm.

Taxonomy and relationships

Tobamovirus

Virus(es) with serologically related virions

Cucumber green mottle mosaic, ribgrass mosaic, tomato mosaic, tobacco mosaic and tobacco mild green mosaic tobamoviruses (see Dubs and Regenmortel, 1990).

Differences between type strain and others

Local lesions caused by the type strain are larger than those of Corbett's (1967) isolate TMV-O.

Best tests for diagnosis

This virus differs from all others known to infect orchids by its virion morphology, and by its ability to induce necrotic local lesions in Nicotiana tabacum cv. Xanthi.

Comments and References

References

• Corbett, M.K. (1967). Phytopathology 57: 164.
• Dubs, M.C. and van Regenmortel, M.H.V. (1990). Arch. Virol. 115: 239.
• Edwardson, J.R. and Zettler, F.W. (1986). In: The Plant Viruses, Vol. 2, The Rod-Shaped Plant Viruses, pp. 233-247; eds M.H.V. van Regenmortel and H. Fraenkel-Conrat. Plenum Press, New York.
• Hennig, B. (1972). In: Atlas of Protein Sequence and Structure, Vol. 5, D287; ed. M.O. Dayhoff. National Biomedical Research Foundation, Washington.
• Jensen, D.D. and Gold, H.A. (1951). Phytopathology 41: 648.
• Kado, C.I., van Regenmortel, M.H.V. and Knight, C.A. (1968). Virology 34: 17.
• Lawson, R.H. and Ali, S. (1975). In: Handbook on Orchid Pests and Diseases, pp. 62-103. American Orchid Society, Cambridge, Mass., U.S.A.
• Paul, H.L. (1975). CMI/AAB Descr. Pl. Viruses No. 155, 4 pp.
• Paul, H.L. and Buchta, U. (1971). J. gen. Virol. 11: 11.
• Paul, H.L., Wetter, K., Wittmann, H.G. and Brandes, J. (1965). Z. VererbLehre 97: 186.

Cite this publication as: Brunt, A.A., Crabtree, K., Dallwitz, M.J., Gibbs, A.J., Watson, L. and Zurcher, E.J. (eds.) (1996 onwards). `Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version: 20^th August 1996.' URL http://biology.anu.edu.au/Groups/MES/vide/

Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.