Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Velvet tobacco mottle sobemovirus

Index

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

Data collated by J.W. Randles, 1986.

Nomenclature

Synonyms

tobacco velvet mottle virus.

Acronym

VTMoV

ICTV decimal code

67.0.1.0.011

Host range and symptoms

Natural host range and symptoms

Symptoms persist.
• Nicotiana velutina - systemic mosaic and leaf malformation.

Transmission

Transmitted by a vector; an insect; Cyrtopeltis nicotianae: Miridae. Transmitted in a semi-persistent manner (atypically). Virus does not multiply in the vector; does not require a helper virus for vector transmission (Gibb and Randles, 1988); transmitted by mechanical inoculation; not transmitted by seed.

Geographical distribution

Spreads in Australia (Randles et al., 1981; G. Behncken and J.W. Randles, unpublished data; Horton, 1981).

Experimental host range

Few (<3) families susceptible.

Diagnostically susceptible host species and symptoms

• Nicotiana clevelandii - chlorotic to necrotic local lesions, then systemic vein yellowing and mosaic.
• Nicotiana glutinosa, N. × edwardsonii - mild systemic mosaic.
• Nicotiana velutina - systemic vein yellowing and mosaic.

Diagnostically insusceptible host species

Solanum nodiflorum.

Maintenance and propagation hosts

Nicotiana clevelandii.

Assay hosts (Local lesions or Whole plants)

Nicotiana clevelandii (L).

Susceptible host species

• Nicotiana clevelandii
• Nicotiana glutinosa
• Nicotiana velutina
• Nicotiana × edwardsonii

Insusceptible host species

• Solanum nodiflorum

Families containing susceptible hosts

• Solanaceae (4/5)

Families containing insusceptible hosts

• Solanaceae (1/5)

Comments on host-range

An isolate of velvet tobacco mottle virus freed from the satellite RNA did not cause local lesions in Nicotiana clevelandii (Francki et al., 1986).

Sources of host-range data

Francki et al. (1985).

Physical and biochemical properties

Properties of particles in sap

TIP: 70 °C. Leaf sap contains many virions.

Purification method

Randles et al. (1981).

Particle morphology

Virions isometric; not enveloped; c. 30 nm in diameter; rounded in profile; without a conspicuous capsomere arrangement.

Physical properties

One sedimenting component in purified preparations; sedimentation coefficient 115 S. Density 1.37 g cm^-3 in CsCl.

Biochemical properties

Virions contain 20 % nucleic acid; 80 % protein; 0 % lipid.

Genome consists of RNA; single-stranded; linear. Total genome size 4.2 kb. Genome unipartite; largest (or only) genome part 4.2 kb. Genomic nucleic acid isolated by Gould (1981); Randles et al. (1981). Infectivity retained when deproteinised with proteases; retained when deproteinised with phenol or detergent. Nucleotide sequence references: Randles et al. (1981); Gould (1981); Haseloff and Symons (1982); Keese and Symons (1986).

NCBI sequence data (Entrez search)

Features of the genome

Non-genomic nucleic acid found in the virions; is subgenomic mRNA (c.1.77 kb for RNA1a and c.0.71 kb for RNA1b, and RNA2 which is of 366-367 nucleotides and has a circular, viroid-like structure, and RNA3, which is the same size and sequence as RNA2, but linear).

Features of proteins

Virion protein(s) one (in native), or three (in dissociated preparations); M_r 37000; coat protein. M_r of 2nd largest 33000. M_r of 3rd largest 31500. Method of preparation: Chu and Francki (1983); Randles et al. (1981).

Replication

Replication does not depend on a helper virus.

Cytopathology

Virions found in all parts of the host plant; in cytoplasm, in nuclei, and in cell vacuoles. Inclusions present in infected cells; are membranous bodies.

Taxonomy and relationships

Sobemovirus

Virus(es) with serologically related virions

Solanum nodiflorum mottle virus (SDI 1-2).

Virus(es) with serologically unrelated virions

Lucerne transient streak, subterranean clover mottle, southern bean mosaic, broad bean mottle, carnation ringspot, cymbidium ringspot, galinsoga mosaic, glycine mottle, narcissus tip necrosis, red clover necrotic mosaic, saguaro cactus, tomato bushy stunt and turnip crinkle viruses (Randles et al., 1981; Francki et al., 1983; Tremaine and Hamilton, 1983).

Additional comments on relationships

Velvet tobacco mottle virus (VTMoV) may be distinguished from solanum nodiflorum mottle virus (SNMV) in host tests; Nicotiana velutina and N. glutinosa are infected systemically by VTMoV, but not by SNMV, whereas Solanum nodiflorum is infected by SNMV but not VTMoV (Randles et al., 1981; Greber, 1981). VTMoV is serologically unrelated to two other viruses which have satellite RNAs, namely lucerne transient streak and subterranean clover mottle viruses (Tien et al., 1981; Francki et al., 1983); these satellites differ in size and sequence from that of VTMoV (Keese et al., 1983; Francki et al., 1985), but those of both VTMoV and SNMV replicate in plants infected with lucerne transient streak virus (Jones and Mayo, 1983; 1985).

Best tests for diagnosis

VTMoV has virions serologically related to those of SNMV, which has a genome with 20-50% homology (Gould and Hatta, 1981), but it fails to infect Solanum nodiflorum and has a smaller satellite (Haseloff and Symons, 1982).

Comments and References

General comments

The virus occurs in gut, haemolymph and faeces, but not salivary glands, of its mirid vector.

References

• Chu, P.W.G. and Francki, R.I.B. (1983). Virology 129. 350.
• Francki, R.I.B., Grivell, C.J. and Gibb, K.S. (1986). Virology 148. 381.
• Francki, R.I.B., Randles, J.W., Chu, P.W.G., Rohozinski, J. and Hatta, T. (1985). In: Subviral Pathogens of Plants and Animals, Viroids and Prions, pp. 265-297; ed. K. Maramorosch and J.J. McKelvey. Academic Press, New York.
• Francki, R.I.B., Randles, J.W., Hatta, T., Davies, C. and Chu, P.W.G. (1983). Pl. Path. 32: 47.
• Gibb, K.S. and Randles, J.W. (1988). Ann. appl. Biol. 112: 427.
• Gibb, K.S. and Randles, J.W. (1990). Ann. appl. Biol. 116: 513.
• Greber, R.S. (1981). Aust. J. biol. Sci. 34: 369.
• Gould, A.R. (1981). Virology 108: 123.
• Haseloff, J. and Symons, R.H. (1982). Nucl. Acids Res. 10: 3681.
• Horton, P. (1981). J. Adelaide Bot. Gard. 3: 1.
• Jones, A.T. and Mayo, M.A. (1983). J. gen. Virol. 64: 1771.
• Jones, A.T. and Mayo, M.A. (1985). Rep. Scottish Crop Res. Inst. 1984, p.190.
• Keese, P. and Symons, R.H. (1986). In: Viroids and Viroid-Like Pathogens, p. 1; ed. J.S. Semancik. CRC Press, Boca Raton, Florida.
• Keese, P., Bruening, G. and Symons, R.H. (1983). FEBS Lett. 159: 185.
• Randles, J.W. and Francki, R.I.B. (1986). CMI/AAB Descr. Pl. Viruses No. 317, 5 pp.
• Randles, J.W., Davies, C., Hatta, T. and Francki, R.I.B. (1981). Virology 108: 111.
• Tien, P., Davies, C., Hatta, T. and Francki, R.I.B. (1981). FEBS Lett. 132: 353.
• Tremaine, J.H. and Hamilton, R.I. (1983). CMI/AAB Descr. Pl. Viruses No. 274, 6 pp.

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.