Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Beet yellows closterovirus

Index

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

Data collated by H. Smith and A. Karasev, 1991.

Nomenclature

Synonyms

sugarbeet yellows closterovirus.

Acronym

BYV

Strains

strains of differing pathogenicity are known to exist.

ICTV decimal code

17.0.1.0.003

Host range and symptoms

Natural host range and symptoms

Symptoms persist. Symptoms yellowing and premature senescence of older leaves.
• Beta vulgaris - vein clearing, then leaves become thick, brittle, yellow with necrotic spots.

Transmission

Transmitted by a vector; an insect; Myzus persicae, Aphis fabae; Aphididae. Not transmitted by Rhopalosiphum padi, Macrosiphum (Sitobion) avenae. Transmitted in a semi-persistent manner. Virus lost by the vector when it moults; does not multiply in the vector; not transmitted congenitally to the progeny of the vector; transmitted by mechanical inoculation (with difficulty); transmitted by grafting; not transmitted by contact between plants; not transmitted by seed; not transmitted by pollen.

Ecology and control

Studies reported by Hull (1968); Harrington et al. (1989).

Geographical distribution

Probably distributed worldwide (wherever Beta vulgaris is grown). Spreads in China.

Experimental host range

Several (3-9) families susceptible. Experimentally infected plants mostly show yellowing or reddening, necrotic spots.

Diagnostically susceptible host species and symptoms

• Tetragonia tetragonioides - stunting, vein clearing, yellowing.
• Montia perfoliata - necrotic spots, reddening and yellowing of older leaves.
• Beta vulgaris - vein clearing then yellowing, thickening and brittleness of leaves; necrotic spots.
• Spinacia oleracea, Stellaria media - yellowing.

Diagnostically insusceptible host species

Brassica spp., Lactuca sativa, Pisum sativum, Nicotiana tabacum, Plantago lanceolata.

Maintenance and propagation hosts

Montia perfoliata, Tetragonia tetragonioides, Beta vulgaris.

Assay hosts (Local lesions or Whole plants)

Beta vulgaris (L and W), Montia perfoliata (L and W), Chenopodium foliosum (L and W), C. quinoa (L).

Susceptible host species

• Atriplex hortensis
• Beta vulgaris
• Celosia cristata
• Chenopodium album
• Chenopodium amaranticolor
• Chenopodium ambrosioides
• Chenopodium capitatum
• Chenopodium foliosum
• Chenopodium hybridum
• Chenopodium quinoa
• Lactuca sativa
• Montia perfoliata
• Nicotiana clevelandii
• Spinacia oleracea
• Stellaria media
• Tetragonia tetragonioides
• Trifolium hybridum

Insusceptible host species

• Brassica campestris
• Brassica campestris ssp. chinensis
• Brassica campestris ssp. napus
• Brassica campestris ssp. pekinensis
• Brassica campestris ssp. rapa
• Brassica juncea
• Brassica oleracea var. botrytis
• Brassica oleracea var. capitata
• Capsella bursa-pastoris
• Chrysanthemum morifolium
• Hyoscyamus niger
• Lactuca sativa
• Nicotiana tabacum
• Petunia × hybrida
• Pisum sativum
• Plantago lanceolata
• Raphanus sativus
• Senecio vulgaris
• Sinapis alba
• Solanum nigrum
• Sonchus oleraceus
• Trifolium incarnatum
• Trifolium pratense
• Trifolium repens
• Trifolium subterraneum
• Vicia faba
• Zinnia elegans

Families containing susceptible hosts

• Amaranthaceae (1/1)
• Caryophyllaceae (1/1)
• Chenopodiaceae (10/10)
• Compositae (1/5)
• Leguminosae-Papilionoideae (1/7)
• Portulacaceae (1/1)
• Solanaceae (1/5)
• Tetragoniaceae (1/1)

Families containing insusceptible hosts

• Compositae (5/5)
• Cruciferae (11/11)
• Leguminosae-Papilionoideae (6/7)
• Plantaginaceae (1/1)
• Solanaceae (4/5)

Sources of host-range data

Russell (1965).

Physical and biochemical properties

Properties of particles in sap

TIP: 55 °C. LIV: 1 days. DEP: log₁₀ minus 4. Leaf sap contains few virions.

Purification method

Kassanis et al. (1977); Karasev et al. (1989).

Particle morphology

Virions filamentous; not enveloped; usually flexuous; with a clear modal length; of 1250 nm; 10 nm wide. Axial canal obscure. Basic helix obvious; pitch of basic helix 3-3.4 nm.

Physical properties

Two sedimenting components in purified preparations; sedimentation coefficient of the fastest 110 S; of the other(s) 80-90 S. Density 1.34 g cm^-3 in CsCl (fixed). A₂₆₀/A₂₈₀ ratio 1.44-1.54.

Biochemical properties

Virions contain 5 % nucleic acid.

Genome consists of RNA; single-stranded; linear. Total genome size 14.5 kb. Genome unipartite; largest (or only) genome part 14.5 kb. Genomic nucleic acid isolated by Karasev: two phenol/SDS extractions. Base composition 23.4 % G; 26.3 % A; 21 % C; 29.3 % U. 5´ terminus of RNA has a methylated nucleotide cap. Infectivity retained when deproteinised with phenol or detergent. Poly A region absent. Additional factor not required for infectivity. Genome has no tRNA-like activity. Nucleotide sequence references: Karasev: 3´-terminal half (6746 nt). EMBL AC. No. X53462.

NCBI sequence data (Entrez search)

Sequence database accession code(s)

• M59452 Em(40)_vi:BYVVCPG Gb(84)_vi:BYVVCPG Beet yellows virus coat protein gene, complete cds, and two ORFs. 8/91 2,724bp.
• X53462 Em(40)_vi:CLBYV3PH Gb(84)_vi:CLBYV3PH Beet yellows virus genome 3´-proximal half, for capsid protein HSP70 related protein, RNA-dep
• X73475 Em(40)_vi:BYVMBPA Gb(84)_vi:BYVMBPA Beet yellows virus (isolate German BYV-G) genes for putative membrane-binding protein, heat s
• X73476 Em(40)_vi:BYVUAA Gb(84)_vi:BYVUAA Beet yellows virus (isolate Ukrainian BYV-U) complete genome. 2/94 15,480bp. 4 sequences.

Features of the genome

Features of the genome: incomplete ORF 1 (nt 3-656) encodes putative polymerase (219 AA). ORF 2 (nt 710-871) encodes 6.4kDa protein (AA 1-54). ORF 3 (nt 874-2667) encodes 65kDa homologue of HSP70 heat shock proteins (AA 1-598). ORF 4 (nt 2576-4234) encodes 64kDa protein (AA1-553). ORF 5 (nt 4185-4832) encodes 24kDa protein, a diverged copy of capsid protein (AA 1-216). ORF 6 (nt 4906-5517) encodes 22.3kDa capsid protein (AA 1-204). ORF 7 (nt 5517-6056) encodes 20kDa protein (AA 1-180). ORF 8 (nt 6034-6564) encodes 21kDa protein (AA 1-177).

Non-genomic nucleic acid not found in the virions. Sub-genomic mRNA found in infected cells. 6 virus specified dsRNA species found in infected cells (at least, including genome-size dsRNA). Size of largest virus specified dsRNA 14.5 kbp; 2nd largest 6.3 kbp; 3rd largest 4.8 kbp; 4th largest 2.7 kbp; 5th largest 1.6 kbp; 6th largest 1 kbp.

Features of proteins

Virion protein(s) one; M_r 22.3 (KDa); capsid protein. Method of preparation: Carpenter et al. (1977). Amino acid composition: Carpenter et al. (1977).

Replication

Replication does not depend on a helper virus.

Cytopathology

Virions found in leaves, roots, mesophyll, vascular parenchyma, phloem, companion cells and all parts of the host plant. Inclusions present in infected cells; are crystals in the cytoplasm; they contain virions.

Taxonomy and relationships

Closterovirus

Additional comments on relationships

Its 6.4kDaprotein is apparently related to 12kDaproteins of potex and carlaviruses. The putative polymerase is related to polymerases of tricornaviruses (bromo and cucumoviruses). Its capsid protein is a member of monophyletic family of capsid proteins encoded by filamentous plant viruses, and its 65kDaprotein is a direct homologue of cell HSP70 heat shock proteins.

Best tests for diagnosis

ELISA using polyclonal antiserum to beet yellows closterovirus is routinely used to identify the virus and distinguish it from beet mild yellowing virus which often occurs with it in sugar beet crops.

Comments and References

References

• Agranovsky, A.A., Boyko, V.P., Karasev, A.V., Lunina, N.A., Koonin, E.V. and Dolja, V.V. (1991). J. gen. Virol. 72: 15.
• Agranovsky, A.A., Boyko, V.P., Karasev, A.V., Koonin, E.V. and Dolja, V.V. (1991). J. mol. Biol. 217: 603.
• Bar-Joseph, M. and Hull, R. (1974). Virology 62: 552.
• Carpenter, J.M., Kassasnis, B. and White, R.F. (1977). Virology 77: 101.
• Dolja, V.V., Karasev, A.V. and Agranovsky, A.A. (1990). In: New Aspects of Positive-Strand RNA Viruses, Amer. Soc. Micro., Washington D.C., U.S.A., p. 31.
• Esau, K. (1960). Virology 11: 317.
• Harrington, R., Dewar, A.M. and George, B. (1989). Ann. appl. Biol. 114: 459.
• Heathcote, G.D. (1988). In: Virus Yellows Monograph IIRB Pests and Diseases Study Group, Rue Montoyer 47, B-1040, Brussels, Belgium.
• Hull, R. (1968). Pl. Path. 17: 1.
• Karasev, A.V., Agranovsky, A.A., Rogov, V.V., Miroschnichenko, N.A., Dolja, V.V. and Atabekov, J.G. (1989). J. gen. Virol. 70: 241.
• Kassanis, B., Carpenter, J.M., White, R.F. and Woods, R.D. (1977). Virology 77: 95.
• Russell, G.E. (1965). Ann. appl. Biol. 55: 245.

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.