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Descriptions and Lists from the VIDE Database

Tobacco mosaic satellivirus

Index

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

Data collated by G. Kurath and J.A. Dodds, 1992.

Nomenclature

Synonyms

satellite tobacco mosaic virus.

Strains

known to exist but none yet described in the literature.

ICTV decimal code

64.0.4.2.003

Host range and symptoms

Natural host range and symptoms

• Nicotiana glauca - symptomless; symptoms may be caused by mixed infection with cucumber mosaic virus or potyviruses.

Transmission

Virus transmitted by mechanical inoculation; not transmitted by seed.

Geographical distribution

Spreads in the USA.

Experimental host range

Several (3-9) families susceptible.

Diagnostically susceptible host species and symptoms

• Nicotiana tabacum, N. glauca, N. benthamiana, N. rustica, N. sylvestris, Lycopersicon esculentum, Physalis floridana, Datura meteloides, Catharanthus roseus - symptoms of the helper virus are unaltered.
• Capsicum annuum - modifies helper virus symptoms by increased chlorosis and transient amelioration of leaf blister.

Diagnostically insusceptible host species

only those that do not support the helper virus.

Maintenance and propagation hosts

Nicotiana tabacum cv. Xanthi for systemic infections, N. tabacum cv. Xanthi-nc for local lesions passage.

Assay hosts (Local lesions or Whole plants)

Capsicum annuum (W).

Susceptible host species

• Capsicum annuum
• Catharanthus roseus
• Chenopodium amaranticolor
• Chenopodium quinoa
• Cucurbita pepo
• Datura metel
• Datura meteloides
• Datura stramonium
• Gomphrena globosa
• Lycopersicon esculentum
• Nicotiana benthamiana
• Nicotiana clevelandii
• Nicotiana glauca
• Nicotiana glutinosa
• Nicotiana rustica
• Nicotiana sylvestris
• Nicotiana tabacum
• Physalis floridana

Families containing susceptible hosts

• Amaranthaceae (1/1)
• Apocynaceae (1/1)
• Chenopodiaceae (2/2)
• Cucurbitaceae (1/1)
• Solanaceae (13/13)

Sources of host-range data

Valverde and Dodds (1986); Valverde et al. (1991).

Purification method

Valverde et al. (1991).

Physical and biochemical properties

Particle morphology

Virions isometric; not enveloped; less than 17 nm in diameter; neither clearly angular or nor rounded in profile; without a conspicuous capsomere arrangement.

Physical properties

One sedimenting component in purified preparations; sedimentation coefficient 42 S.

Biochemical properties

Virions contain 25 % nucleic acid; 75 % protein.

Genome consists of RNA; single-stranded; linear. Total genome size 1.059 kb. Genome unipartite; largest (or only) genome part 1.059 kb. Genomic nucleic acid isolated by proteinase K treatment and phenol:chloroform extraction. Base composition 24.4 % G; 26.1 % A; 21.3 % C; 28.2 % U. 5´ terminus of RNA has an unusual type; is non-phosphorylated. Infectivity retained when deproteinised with proteases; retained when deproteinised with phenol or detergent. Poly A region absent. Additional factor not required for infectivity. Nucleotide sequence references: Mirkov et al. (1989).

NCBI sequence data (Entrez search)

Sequence database accession code(s)

Genbank M25782.

Features of the genome

Features of the genome: ORF 1, nt 53-229, encodes a 6.8kDa protein of unknown function. This ORF has been translated in vitro but its role in vivo has not been ascertained. ORF 2, nt 163-642, encodes the virion coat protein both in vitro and in vivo. The 3´ terminal 240 nt share 65% overall sequence similarity with the 3´ terminus of TMV-U1. This includes two regions of near identity which are 40 and 50 nt long.

The sequence of tobacco mosaic satellite virus genomic RNA indicates that, probably, much of it is base paired.

Non-genomic nucleic acid not found in the virions. Sub-genomic mRNA not found in infected cells. 1 virus specified dsRNA species found in infected cells. Size of largest virus specified dsRNA 1.1 kbp.

Features of proteins

Virion protein(s) one; M_r 17500; coat protein. Method of preparation: Valverde and Dodds (1987).

Virus-coded non-virion proteins isolated (Mirkov et al. (1989)); one protein found (in vitro). M_r 68000.

Replication

Genome replicates in cytoplasmic viroplasms. Replication depends on co-infection with a helper virus; but the specific basis of dependence is not known.

Cytopathology

Virions found in leaves, roots, mesophyll and epidermis; in cytoplasm. Inclusions present in infected cells; are crystals in the cytoplasm, viroplasms, and unusual in shape; unit membranes with vesicles containing fibrillar material surround viral crystals; proteinaceous bodies are contained within this inclusion; they contain virions.

Taxonomy and relationships

satellivirus

Virus(es) with serologically unrelated virions

Tobacco necrosis satellite, panicum mosaic satellite, and maize white line mosaic satellite viruses.

Additional comments on relationships

This satellite virus is found naturally associated with tobacco mild green mosaic tobamovirus, but can be experimentally coinfect with any of tobamoviruses.

Best tests for diagnosis

Tobacco mosaic satellite virus causes no symptom modification in any host plants except Capsicum annuum. Therefore the quickest way to identify it is by Ouchterlony diffusion tests with tobacco mosaic satellite virus specific antiserum available from J.A. Dodds.

Comments and References

General comments

Tobacco mosaic satellite virus crystallizes very readily (Koszelak et al., 1989). The virion structure has recently been resolved to the 0.3nm level (A. McPherson, personal communication).

References

• Dodds, J.A. (1991). Can. J. Pl. Pathol. 13: 192.
• Kim, K.S., Valverde, R.A. and Dodds, J.A. (1989). J. Ultrastruct. Mol. Struct. Res. 102: 196.
• Koszelak, S., Dodds, J.A. and McPherson, A. (1989). J. mol. Biol. 209: 323.
• Mirkov, T.E., Kurath, G., Mathews, D.M., Elliot, K., Dodds, J.A. and Fitzmaurice, L. (1990). Virology 179: 395.
• Mirkov, T.E., Mathews, D.M., DuPlessis, D.H. and Dodds, J.A. (1989). Virology 170: 139.
• Valverde, R.A. and Dodds, J.A. (1986). J. gen. Virol. 67: 1875.
• Valverde, R.A. and Dodds, J.A. (1987). J. gen. Virol. 68: 965.
• Valverde, R.A., Heick, J.A. and Dodds, J.A. (1991). Phytopathology 81: 99.

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.