Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Watercress yellow spot virus

Index

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

Data collated by J.A. Walsh, 1991.

Nomenclature

Synonyms

virus des taches jaunes du cresson.

ICTV decimal code

79.0.P.DE.44

Host range and symptoms

Natural host range and symptoms

Symptoms vary cyclically over a few weeks, vary seasonally, and disappear soon after infection (sometimes). Symptoms chlorotic spotting and blotching.
• Rorippa nasturtium-aquaticum - chlorotic spotting and blotching, mainly on leaf veins, some leaves malformed and maybe totally chlorotic.

Transmission

Transmitted by probably a vector; probably a fungus; probably Spongospora subterranea f.sp. Nasturtium; Plasmodiophorales. Not transmitted by Myzus persicae. Virus transmitted by mechanical inoculation (with great difficulty).

Ecology and control

Studies reported by Spire (1962); Walsh et al. (1989a); Walsh (1990); Walsh and Phelps (1991).

Geographical distribution

Spreads in France and the UK (Spire, 1962; Walsh et al., 1989a).

Experimental host range

Few (<3) families susceptible. Experimentally infected plants mostly show necrotic local lesions, then indistinct chlorotic blotches or ringspots.

Diagnostically susceptible host species and symptoms

• Rorippa nasturtium-aquaticum - spotting and blotching, but less severe than in naturally infected plants.
• Chenopodium quinoa - necrotic local lesions, not systemic.
• Nicotiana clevelandii - indistinct chlorotic blotches, sometimes ringspots, not systemic.
• Brassica juncea cv. Tendergreen - symptomless.
• Nicotiana glutinosa - ringspots, not systemic.
• Brassica napus var. napus cv. Mikado - pinpoint necrotic local lesions.
• Barbarea verna - symptomless.
• Chenopodium amaranticolor - necrotic local lesions, not systemic.

Diagnostically insusceptible host species

Brassica campestris ssp. pekinensis, Lactuca sativa, Brassica campestris ssp. rapa cv. Just Right, Nicotiana tabacum cv. White Burley.

Assay hosts (Local lesions or Whole plants)

Chenopodium quinoa (L), C. amaranticolor (L), Nicotiana clevelandii (L).

Susceptible host species

• Barbarea verna
• Brassica juncea
• Brassica napus var. napus (cv. Mikado)
• Chenopodium amaranticolor
• Chenopodium quinoa
• Nicotiana benthamiana
• Nicotiana clevelandii
• Nicotiana glutinosa
• Rorippa nasturtium-aquaticum

Insusceptible host species

• Brassica campestris ssp. pekinensis
• Brassica campestris ssp. rapa (cv. Just Right)
• Lactuca sativa
• Nicotiana tabacum

Families containing susceptible hosts

• Chenopodiaceae (2/2)
• Cruciferae (4/6)
• Solanaceae (3/4)

Families containing insusceptible hosts

• Compositae (1/1)
• Cruciferae (2/6)
• Solanaceae (1/4)

Sources of host-range data

Walsh et al. (1989b).

Physical and biochemical properties

Properties of particles in sap

TIP: 65 °C. LIV: less than 1 days. DEP: log₁₀ minus 2-3. Infectivity of sap decreased by treatment with di-ethyl ether. Leaf sap contains few virions. Electron microscopy: ISEM often required to see virions in leaf sap.

Purification method

Walsh et al. (1989a).

Particle morphology

Virions isometric; not enveloped; 27 nm in diameter (Spire, 1962), or 37-38 nm in diameter (Walsh et al., 1989a); rounded in profile; with a conspicuous capsomere arrangement (sometimes).

Physical properties

Probably one sedimenting component in purified preparations; sedimentation coefficient 133.8 S. Density 1.335 g cm^-3 in CsCl. A₂₆₀/A₂₈₀ ratio 1.53-1.66.

Biochemical properties

Virions contain 18 % nucleic acid.

Genome possibly consists of RNA; single-stranded; possibly linear.

Features of proteins

Virion protein(s) one; M_r 43500; coat protein.

Cytopathology

Virions found in roots and sometimes in leaves.

Taxonomy and relationships

(ungrouped)

Additional comments on relationships

Shares some properties with tombusviruses, including the sedimentation coefficient of the virions and the coat protein molecular weight, but its virions are unstable, and are larger than those of tombusviruses.

Best tests for diagnosis

Sero-diagnosis by ELISA, ISEM and gel diffusion.

Comments and References

General comments

Watercress chlorotic leafspot, although initially attributed to virus infection (Tomlinson and Hunt, 1987), is now considered to be induced by a virus-like agent (Tomlinson, 1988).

References

• Spire, D. (1962). Ann. Epiphyt. 13: 39.
• Walsh, J.A. (1990). First Symp. of Int. Working Group on Plant Viruses with Fungal Vectors, German Phytomedical Society. Ulmer, Stuttgart, 173
• Walsh, J.A. and Phelps, K. (1991). Pl. Path. in press.
• Tomlinson, J.A. (1988). In: Viruses with Fungal Vectors; ed. J.I. Cooper and M.J.C. Asher. Wellesbourne, U.K., Association of Applied Biologists.
• Tomlinson, J.A. and Hunt, J. (1987). Ann. appl. Biol. 110: 75.
• Walsh, J.A., Clay, C.M. and Miller, A. (1989a). EPPO Bull. 19: 463.
• Walsh, J.A., Clay, C.M., Miller, A. and Rowe, J.C. (1989b). Aspects Appl. Biol. 22: 101.

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.