Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Silene X (?) potexvirus

Index

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

Data collated by R.I. Hamilton, 1991.

Nomenclature

ICTV decimal code

56.0.1.T.D.11

Host range and symptoms

Natural host range and symptoms

Symptoms persist.
• Silene latifolia ssp. alba - usually symptomless, sometimes a slight mosaic, stunting.

Transmission

Infected plants occur in orchards and on roadsides which are frequently mown. Virus transmitted by mechanical inoculation; not transmitted by seed.

Geographical distribution

Spreads in Canada.

Experimental host range

Several (3-9) families susceptible. Experimentally infected plants mostly show usually symptomless or systemic mosaic.

Diagnostically susceptible host species and symptoms

• Chenopodium amaranticolor, C. quinoa - chlorotic local lesions; systemic mosaic.
• Nicotiana benthamiana, N. clevelandii - necrotic local lesions; systemic mosaic.
• Vigna unguiculata - chlorotic rings; systemic mosaic.

Diagnostically insusceptible host species

Narcissus spp., Solanum tuberosum (5 cultivars).

Maintenance and propagation hosts

Chenopodium quinoa.

Assay hosts (Local lesions or Whole plants)

Chenopodium amaranticolor (W), C. quinoa (W), Gomphrena globosa (L), Phaseolus vulgaris (L), Pisum sativum (L).

Susceptible host species

• Chenopodium amaranticolor
• Chenopodium quinoa
• Cucumis sativus
• Dianthus barbatus
• Gomphrena globosa
• Nicotiana benthamiana
• Nicotiana clevelandii
• Nicotiana tabacum
• Phaseolus vulgaris
• Pisum sativum
• Silene latifolia ssp. alba
• Spergula arvensis
• Stellaria media
• Vigna unguiculata

Insusceptible host species

• Narcissus
• Solanum tuberosum

Families containing susceptible hosts

• Amaranthaceae (1/1)
• Caryophyllaceae (4/4)
• Chenopodiaceae (2/2)
• Cucurbitaceae (1/1)
• Leguminosae-Papilionoideae (3/3)
• Solanaceae (3/4)

Families containing insusceptible hosts

• Amaryllidaceae (1/1)
• Solanaceae (1/4)

Sources of host-range data

Wakarchuk and Hamilton (1989).

Physical and biochemical properties

Properties of particles in sap

Leaf sap contains few virions. Electron microscopy: aldehyde fixation.

Purification method

Brunt (1966).

Particle morphology

Virions filamentous; not enveloped; usually flexuous; with a clear modal length; of 546 nm; 13 nm wide. Axial canal obscure. Basic helix obscure.

Physical properties

Density 1.32 g cm^-3 in CsCl (»0.3). A₂₆₀/A₂₈₀ ratio 1.18.

Biochemical properties

Genome consists of RNA; single-stranded; linear. Total genome size 6.9 kb. Genome unipartite; largest (or only) genome part 6.9 kb. Genomic nucleic acid isolated by Hamilton: phenol extraction of purified virus in 100 mm NH₄CO₃ (pH 9.0), 10 mm EDTA and 1% SDS; precipitation of RNA in EtOH. Infectivity retained when deproteinised with phenol or detergent. Poly A region present. Additional factor not required for infectivity.

Features of the genome

Non-genomic nucleic acid found in the virions; is subgenomic mRNA. 4 virus specified dsRNA species found in infected cells. Size of largest virus specified dsRNA 17.1 kbp; 2nd largest 7 kbp; 3rd largest 5.7 kbp; 4th largest 4.6 kbp.

Features of proteins

Virion protein(s) one; M_r 29000; capsid protein. Method of preparation: Laemmli (1970).

Replication

Replication does not depend on a helper virus.

Cytopathology

Virions found in leaves and mesophyll; in cytoplasm and in cell vacuoles. Inclusions absent from infected cells.

Taxonomy and relationships

Possible Potexvirus

Virus(es) with serologically related virions

Argentine plantago, clover yellow mosaic, cymbidium mosaic, daphne X, hydrangea ringspot, narcissus mosaic, viola mottle and white clover mosaic viruses.

Best tests for diagnosis

Silene X virus often occurs mixed with ribgrass mosaic virus in Silene latifolia ssp. alba. It rapidly infects Chenopodium quinoa systemically, whereas ribgrass mosaic virus does it more slowly.

Comments and References

References

• Brunt, A.A. (1966). Ann. appl. Biol. 58: 13.
• Laemmli, U.K. (1970). Nature, Lond. 227: 680.
• Wakarchuk, D.A. and Hamilton, R.I. (1989). Intervirology 30: 330.

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.