Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Pea enation mosaic enamovirus

Index

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

Data collated by A.J. Cockbain, 1980. Revised 1983.

Nomenclature

Synonyms

enation pea mosaic virus.

Acronym

PEMV

ICTV decimal code

24.0.1.0.001

Host range and symptoms

Natural host range and symptoms

Symptoms persist.
• Cicer arietinum, Lathyrus odoratus, Lens culinaris, Medicago arabica, Pisum sativum, Trifolium incarnatum, Vicia faba, Vicia sativa - hyaline local lesions with enations, mosaic, puckering and stunting.

Transmission

Transmitted by a vector; an insect; Acyrthosiphon pisum, Myzus persicae; Aphididae. Transmitted in a persistent manner. Virus retained when the vector moults; does not multiply in the vector; not transmitted congenitally to the progeny of the vector; can help the vector transmission of another virus (bean yellow vein banding umbravirus); transmitted by mechanical inoculation; probably transmitted by seed.

Geographical distribution

Spreads in Canada, China, Iran, the UK, and the USA.

Experimental host range

Several (3-9) families susceptible.

Diagnostically susceptible host species and symptoms

• Chenopodium album, C. amaranticolor - chlorotic local lesions.
• Lathyrus odoratus, Medicago arabica, Pisum sativum, Trifolium incarnatum, Vicia faba - systemic mosaic, hyaline lesions with enations, puckering.
• Nicotiana clevelandii - systemic mosaic and puckering.

Maintenance and propagation hosts

Pisum sativum and Vicia faba, which is less satisfactory.

Assay hosts (Local lesions or Whole plants)

Chenopodium album (L), C. amaranticolor (L), C. quinoa (L).

Susceptible host species

• Chenopodium album
• Chenopodium amaranticolor
• Chenopodium quinoa
• Cicer arietinum
• Lathyrus odoratus
• Lens culinaris
• Lespedeza stipulacea
• Lupinus albus
• Lupinus angustifolius
• Medicago arabica
• Medicago sativa
• Melilotus albus
• Nicotiana clevelandii
• Phaseolus vulgaris
• Pisum sativum
• Trifolium hybridum
• Trifolium incarnatum
• Trifolium repens
• Trifolium subterraneum
• Vicia faba
• Vicia sativa
• Vicia villosa

Insusceptible host species

• Cyamopsis tetragonoloba
• Gomphrena globosa
• Lotus corniculatus
• Medicago hispida
• Nicotiana rustica
• Sesbania exaltata
• Trifolium dubium
• Trifolium pratense

Families containing susceptible hosts

• Chenopodiaceae (3/3)
• Leguminosae-Papilionoideae (18/24)
• Solanaceae (1/2)

Families containing insusceptible hosts

• Amaranthaceae (1/1)
• Leguminosae-Papilionoideae (6/24)
• Solanaceae (1/2)

Sources of host-range data

McEwen and Schroeder (1956); Hagedorn et al. (1964); Thottappilly (1972); Cockbain and Gibbs (1973); Hampton et al. (1978).

Physical and biochemical properties

Properties of particles in sap

TIP: 55-65 °C. LIV: 4 days. DEP: log₁₀ minus 4. Infectivity of sap not changed by treatment with di-ethyl ether. Leaf sap contains many virions. Electron microscopy: aldehyde fixation necessary for slower sedimenting virions.

Purification method

Hull and Lane (1973); Mahmood and Peters (1973).

Particle morphology

Virions isometric; not enveloped; 25 and 28 nm in diameter (T and B, respectively); rounded in profile, or angular in profile (some hexagonal, others pentagonal or ovoid); without a conspicuous capsomere arrangement.

Physical properties

Two sedimenting components in purified preparations; sedimentation coefficient 112 S (B); of the other(s) 99 S (T). Density 1.436 g cm^-3 in CsCl (for B component; top component degraded in CsCl). Density 1.36 in D₂O and 1.380 in Cs₂SO₄ for both components. Isoelectric point pH 5-6. A₂₆₀/A₂₈₀ ratio 1.63 (unfractionated prparations).

Biochemical properties

Virions contain 28 % nucleic acid; 72 % protein; 0 % lipid.

Genome consists of RNA; single-stranded; linear. Total genome size 9.96 kb. Genome of two parts; largest (or only) genome part the larger, RNA-1 5.71 kb; the 2nd largest RNA-2 4.25 kb (see Taxonomy and Relationships - below). Base composition 26.6 % G; 24.1 % A; 24.5 % C; 24.8 % U. 5´ terminus of RNA has a VPg. Infectivity lost when deproteinised with proteases. Poly A region absent.

NCBI sequence data (Entrez search)

Sequence database accession code(s)

• L04573 Em(40)_vi:PEQPOLYZ Gb(84)_vi:PEQPOLYZ Pea enation mosaic virus ORF 1, complete cds; ORF 2, complete cds; ORF 3, 3´ end cds; coat protein gene, complete cds; ORF 5, 3´ end cds.
• U03563 Em(40)_vi:PE03563 Gb(84)_vi:PEU03563 Pea enation mosaic virus 65kDa viral replicase gene, complete cds. 6/94 4,253bp.
• U03564 Em(40)_vi:PE03564 Gb(84)_vi:PEU03564 Pea enation mosaic virus WSG satellite RNA. 5/94 717bp.
• Z48507 Em(43)_vi:Pemvcp Gb(89)_vi:Pemvcp Pea enation mosaic virus RNA for coat protein. 2/95 1,482bp.

Features of the genome

Features of the genome: Five ORFs (RNA-1). The coat protein and the 54kDa protein are probably translated from a subgenomic mRNA. RNA-2 also has 5 ORFs.

Non-genomic nucleic acid found in the virions; is satellite RNA (probably); of 0.72 kb.

Features of proteins

Virion protein(s) three; M_r of the largest, but minor, protein 54000; facilitates aphid transmission; it comprises the coat protein with a 'read-through' of a 33kDa protein encoded by the 3´terminal gene. M_r of 2nd largest major 21000; coat protein. M_r of 3rd largest 17500; genome-linked protein (VPg).

Cytopathology

Virions found in leaves and phloem; in nuclei, in cytoplasm, and in cell vacuoles. Inclusions present in infected cells; are unusual in shape; aggregates in the cytoplasm and nucleus; they contain virions. Other cellular changes: phloem necrosis with dark staining spherical bodies in sieve tubes.

Taxonomy and relationships

Enamovirus (the type species)

Additional comments on relationships

This virus is probably a complex that has arisen by `symbiogenesis' (Gibbs, 1995). Tests with transcripts of cDNAs encoding the two genomic components (Demler et al., 1993, 1994) show that RNA-1 can replicate alone in protoplasts, but not in intact plants, whereas RNA-2 can replicate alone in both protoplasts and plants. Thus RNA-2 complements RNA-1 allowing it to be transmitted in sap, and to spread systemically, whereas RNA-1 directs virion protein synthesis and assembly into virions.

Comments and References

References

• Adam, G., Sander, E. and Shepherd, R.J. (1979). Virology 92: 1.
• Clark, R.G. and Bath, J.E. (1977). Phytopathology 67: 1035.
• Cockbain, A.J. and Gibbs, A.J. (1973). Ann. appl. Biol. 73: 177.
• Demler, S.A. and de Zoeten, G.A. (1989). J. gen. Virol. 70: 1075.
• Demler, S.A. and de Zoeten, G.A. (1991). J. gen. Virol. 72: 1819.
• Demler, S.A., Rucker, D.G. and de Zoeten, G.A. (1993). J. gen. Virol. 74: 1.
• Demler, S.A., Borkhrenious, O.N. Rucker, D.G. and de Zoeten, G.A. (1994). J. gen. Virol. 75: 997.
• De Zoeten, G.A., Powell, C.A., Gaard, G. and German, T.L. (1976). Virology 70: 459.
• Gabriel, C.J. and de Zoeten, G.A. (1984). Virology 139: 223.
• German, T.L. and de Zoeten, G.A. (1975). Virology 66: 172.
• German, T.L., de Zoeten, G.A. and Hall, T.C. (1978). Intervirology 9: 226.
• Gibbs, M.J. (1995). D. Phil. thesis, University of Oxford.
• Gonsalves, D. and Shepherd, R.J. (1972). Virology 48: 709.
• Harris, K.F., Bath, J.E., Thottapilly, G. and Hooper, G.R. (1975). Virology 65: 148.
• Hagedorn, D.J., Layne, R.E.C. and Ruppel, E.G. (1964). Phytopathology 54: 843.
• Hampton, R., Beczner, L., Hagedorn, D., Bos, L., Inouye, T., Barnett, O., Musil, M. and Meiners, J. (1978). Phytopathology 68: 989.
• Hull, R. (1977). J. gen. Virol. 34: 183.
• Hull, R. and Lane, L.C. (1973). Virology 55: 1.
• Hull, R. (1977). In: Aphids as Virus Vectors, p. 137; ed. K. F. Harris and K. Maramorosch. Academic Press, New York.
• Mahmood, K. and Peters, D. (1973). Neth. J. Pl. Path. 79: 138.
• McEwen, F.L. and Schroeder, W.T. (1956). Pl. Dis. Reptr 40: 11.
• Osborn, H.T. (1935). Phytopathology 25: 160.
• Peters, D. (1982). CMI/AAB Descr. Pl. Viruses No. 257, 5 pp.
• Powell, C.A., de Zoeten, G.A. and Gaard, G. (1977). Virology 78: 135.
• Shepherd, R.J. (1970). CMI/AAB Descr. Pl. Viruses No. 25, 4 pp.
• Thottappilly, G. (1972). Z. PflKrankh. PflPath. PflSchutz. 79: 686.

Illustrations

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.