16
June 1970
Family: Secoviridae
Genus: Nepovirus
Species: Arabis mosaic virus
Acronym: ArMV


Arabis mosaic virus

A. F. Murant
Scottish Horticultural Research Institute, Invergowrie, Dundee, Scotland

Contents

Introduction
Main Diseases
Geographical Distribution
Host Range and Symptomatology
Strains
Transmission by Vectors
Transmission through Seed
Transmission by Grafting
Transmission by Dodder
Serology
Nucleic Acid Hybridization
Relationships
Stability in Sap
Purification
Properties of Particles
Particle Structure
Particle Composition
Properties of Infective Nucleic Acid
Molecular Structure
Genome Properties
Satellites
Relations with Cells and Tissues
Ecology and Control
Notes
References
Acknowledgements
Figures

Introduction

Described by Smith & Markham (1944).

Selected synonyms
Raspberry yellow dwarf virus (Rev. appl. Mycol. 37: 669; 39: 261)
Rhabarber-Mosaik-Virus (rhubarb mosaic virus) (Rev. appl. Mycol. 37: 64; 39: 561)

An RNA-containing virus which has isometric particles about 30 nm in diameter and occurs in Europe. It is readily sap-transmissible, has a wide host range, infects the seed of many host plants, and is transmitted by the nematode Xiphinema diversicaudatum.

Main Diseases

Causes yellow dwarf of raspberry, mosaic and yellow crinkle of strawberry, stunt mottle of cucumber, chlorotic stunt of lettuce, stunting and necrosis of celery, and yellow net of Forsythia intermedia, and is one of the causes of mosaic of rhubarb. It occurs in many other plants including sugar beet, hop, horseradish, Narcissus, rose, Sambucus nigra, Ligustrum vulgare, white clover and grapevine. Grapevine plants more commonly contain grapevine fanleaf virus, which is distantly serologically related to arabis mosaic virus, and is the subject of another Description. In association with viruses of the prunus necrotic ringspot type it causes one form of rasp-leaf of cherry.

Geographical Distribution

Natural spread is not reported outside Europe. The virus has been found in stocks of rhubarb in Canada (R. Stace-Smith, personal communication).

Host Range and Symptomatology

Occurs naturally in many species of wild and cultivated monocotyledonous and dicotyledonous plants. It infected 93 species in 28 dicotyledonous families when transmitted by mechanical inoculation (Schmelzer, 1962), and it is also reported to infect the roots of the gymnosperm Chamaecyparis lawsoniana. It infects almost all commonly used herbaceous test plants, but isolates of the virus differ in virulence.

Diagnostic species
Chenopodium amaranticolor and C. quinoa. Chlorotic local lesions (Fig.1); systemic chlorotic mottle (Fig.5).

Cucumis sativus (cucumber). Chlorotic local lesions; systemic yellow spots or veinbanding (Fig.3), subsequently fading. Plants then stop growing.

Nicotiana tabacum cv. White Burley (tobacco). Chlorotic or necrotic local lesions. Some isolates give systemic yellow spots and rings (Fig.2) and line patterns. Leaves produced later appear almost normal but contain virus.

Phaseolus vulgaris cv. The Prince (French bean). Faint chlorotic local lesions; systemic necrosis and distortion.
Petunia hybrida. Local chlorotic lesions or necrotic rings. Systemic vein-clearing or chlorotic rings and line-patterns (Fig.4). Leaves produced subsequently are symptomless but contain virus.

Propagation species
Petunia hybrida is a useful plant for maintaining cultures; P. hybrida and Nicotiana clevelandii are good sources of virus for purification.

Assay species
Chenopodium amaranticolor can be used to assay virulent isolates; with avirulent isolates, lesions on most hosts are too indistinct to count. Cucumis sativus is a convenient ‘bait plant’ in nematode transmission tests.

Strains

Most isolates seem to differ little from the type strain, apart from minor differences in virulence. However, the strain from hop (Bock, 1966) infects only Chenopodium amaranticolor and C. quinoa of the herbaceous test plants tried, and differs serologically from the type strain; its vector is unknown.

Transmission by Vectors

The type strain is transmitted by the free-living, soil-inhabiting nematodes, Xiphinema diversicaudatum (Jha & Posnette, 1959; Harrison & Cadman, 1959) and X. coxi (Fritzsche & Schmidt, 1963). Larvae and adults of X. diversicaudatum both transmit, but the adult does not pass the virus to its progeny nor is the virus retained after moulting. X. diversicaudatum can acquire the virus after access to infected plants for 1 day and can inoculate bait plants in 3 days (Jha & Posnette, 1961). The nematodes retain virus for at least 31 days when kept in fallow soil (Jha & Posnette, 1961) and for at least 8 months when kept on a virus-immune variety of raspberry (Harrison & Winslow, 1961).

Virus-like particles were associated with the cuticular linings of the lumina of the odontophore (stylet extension) and the oesophagus of X. diversicaudatum which had fed on plants infected with arabis mosaic virus (Taylor & Robertson, 1970).

Transmission through Seed

Seed-borne in at least 15 spp. in 12 plant families. In many hosts more than 10%, and in some nearly 100%, of progeny seedlings are infected. Many plants infected through seed show no symptoms (Lister & Murant, 1967; Murant & Lister, 1967).

Transmission by Dodder

Cuscuta subinclusa and C. californica transmitted the virus frequently, C. campestris only occasionally (Schmelzer, 1962).

Serology

Antisera with titres of 1/500-1/1000 are readily obtained. Precipitin tests in tubes, microprecipitin tests, or gel-diffusion tests in 1% agar are satisfactory. The virus produces one line of precipitation in gel-diffusion tests.

Relationships

Most isolates seem closely related serologically to the type strain (Cadman, 1960; Hollings, 1963). The hop line-pattern strain can be distinguished from the type strain by spur-formation in gel-diffusion tests (Bock, 1966), but the extent of difference was not reported.

Harrison (1958) found that cross-protection occurred between different isolates but Jha (1961) and Hollings (1963) reported that protection was sometimes incomplete or non-reciprocal. Schmelzer (1963) found that cross-protection was more consistent between isolates of arabis mosaic virus than between those of tomato black ring virus.

Arabis mosaic virus is distantly serologically related to grapevine fanleaf virus (Cadman, Dias & Harrison, 1960). It also resembles in many properties other nepoviruses (strawberry latent ringspot, tobacco ringspot, tomato black ring and tomato ringspot) but is unrelated to them serologically.

Stability in Sap

In Petunia hybrida sap, the virus lost infectivity after 10 min at 55-61°C, storage at room temperature for 1-2 weeks, or dilution to 10-3-10-5 (Harrison, 1958). Some strains survive longer periods in sap at room temperature (Hollings, 1963; Schmelzer, 1962).

Purification

A modification of Steere’s butanol/chloroform method is useful (Harrison & Nixon, 1960).

Properties of Particles

The particles are all the same size but sediment as three components, apparently empty protein shells (T) and two kinds of nucleoprotein (M and B).

Sedimentation coefficients (s20,w) (svedbergs): 53 (T), 93 (M), 126 (B) (R. Stace-Smith, personal communication).

Other physical properties unknown.

Particle Structure

Isometric, about 30 nm in diameter with a 5 or 6-sided angular outline (Harrison & Nixon, 1960). The protein shell may be composed of 42 morphological subunits (Agrawal, 1967). Electron micrographs show some particles completely, some partially and some not penetrated by negative stain (Fig.6). These particles possibly correspond to the T, M and B components.

Particle Composition

RNA: Single-stranded; about 27% (M) and 41% (B) of the particle weight (estimated from the sedimentation coefficients).

Relations with Cells and Tissues

In Chenopodium amaranticolor, inclusion bodies form adjacent to the cell nuclei; some of them contain particles arranged in spheroidal shells (Gerola et al., 1965; I. M. Roberts, personal communication).

Notes

Diseases caused by this virus are distributed patchily in crops because of the slow migration of the soil-inhabiting vectors, Xiphinema spp. The virus tends to occur in soils together with strawberry latent ringspot virus, with which it shares the vector, X. diversicaudatum. These two viruses are difficult to distinguish from each other with certainty by their reactions in host plants but are serologically unrelated. As with other nepoviruses, serological tests provide the only reliable means of identification.

References

  1. Agrawal, J. Ultrastruct. Res. 17: 84, 1967.
  2. Bock, Ann. appl. Biol. 57: 131, 1966.
  3. Cadman, Virology 11: 653, 1960.
  4. Cadman, Dias & Harrison, Nature, Lond. 187: 577, 1960.
  5. Fritzsche & Schmidt, Naturwissenschaften 50: 163, 1963.
  6. Gerola, Bassi & Betto, Caryologia 18: 353, 1965.
  7. Harrison, Ann. appl. Biol. 46: 221, 1958.
  8. Harrison & Cadman, Nature, Lond. 184: 1624, 1959.
  9. Harrison & Nixon, Virology 12: 104, 1960.
  10. Harrison & Winslow, Ann. appl. Biol. 49: 621, 1961.
  11. Hollings, J. hort. Sci. 38: 138, 1963.
  12. Jha, J. hort. Sci. 36: 219, 1961.
  13. Jha & Posnette, Nature, Lond. 184: 962, 1959.
  14. Jha & Posnette, Virology 13: 119, 1961.
  15. Lister & Murant, Ann. appl. Biol. 59: 49, 1967.
  16. Murant & Lister, Ann. appl. Biol. 59: 63, 1967.
  17. Schmelzer, Phytopath. Z. 46: 105, 1962.
  18. Schmelzer, Phytopath. Z. 46: 315, 1963.
  19. Smith & Markham, Phytopathology 34: 324, 1944.
  20. Taylor & Robertson, Rep. Scott. hort. Res. Inst., 1969: 63, 1970.


Figure 1

Local lesions in Chenopodium amaranticolor.

Figure 2

Systemic symptoms in Nicotiana tabacum cv. White Burley.

Figure 3

Systemic symptoms in Cucumis sativus.

Figure 4

Systemic vein-clearing in Petunia hybrida.

Figure 5

Systemic symptoms in Chenopodium amaranticolor.

Figure 6

Particles mounted in phosphotungstate. Bar represents 100 nm.