Plant Viruses
Online 
Descriptions and Lists from
the VIDE Database
Nepoviruses:
Comoviridae
Index
Nomenclature
ICTV reference
Definitive species
Tentative species
Host range and
symptoms
Natural host range and symptoms
Symptoms
persist (15/29), or vary seasonally (7/29), or disappear soon after infection
(8/29), or none (3/29).
Transmission
Transmitted by a vector (18/20), or means
not involving a vector (2/20); a nematode (17/17); Dorylamidae (11/11). Virus
lost by the vector when it moults (1/1); does not multiply in the vector (1/1);
not transmitted congenitally to the progeny of the vector (1/1); does not
require a helper virus for vector transmission (2/2); transmitted by mechanical
inoculation (38/38); transmitted by grafting (23/23); not transmitted by contact
between plants (19/19); transmitted by seed (25/28), or not transmitted by seed
(3/28); transmitted by pollen to the seed (7/9), or transmitted by pollen to the
pollinated plant (4/9), or not transmitted by pollen (1/9).
Experimental host range
Many (>9) families susceptible
(17/38), or several (3-9) families susceptible (19/38), or few (<3) families
susceptible (2/38).
Susceptible host species
Insusceptible host species
Families containing susceptible hosts
Families containing
insusceptible hosts
Physical and
biochemical properties
Properties of particles in sap
TIP:
50-60.63-75 °C. LIV: 1-15.9-100 days. DEP: log10 minus 2 (4/37), or 3
(21/37), or 4 (24/37), or 5 (16/37), or 6 (2/37). Infectivity of sap not changed
by treatment with di-ethyl ether (7/7). Leaf sap contains few virions
(19/26), or contains many virions (7/26).
Particle morphology
Virions isometric; not enveloped
(36/36); 22-27.69-33 nm in diameter; rounded in profile (1/37), or angular in
profile (37/37); with a conspicuous capsomere arrangement (4/26), or without a
conspicuous capsomere arrangement (22/26).
Physical properties
One sedimenting component in purified
preparations (3/35), or two sedimenting components in purified preparations
(6/35), or three sedimenting components in purified preparations (26/35), or
four sedimenting components in purified preparations (2/35); sedimentation
coefficient 112-125.7-135 S; of the other(s) 40-78.71-128 S.
Density 1.2-1.451-1.53 g cm-3 in CsCl. Isoelectric point pH 4-5.437-7.5.
A260/A280 ratio 0.65-1.493-1.97.
Biochemical properties
Virions contain 0-23.04-46 %
nucleic acid; 54-77.64-100 % protein; 0 % lipid.
Genome consists of RNA (33/33); single-stranded (33/33); linear (18/18).
Total genome size 10.1-12.82-16.9 kb. Genome of two parts (33/33); largest (or
only) genome part 5.3-7.549-9.5 kb; the 2nd largest 3.774-5.214-7.5 kb. Base
composition 21.6-24.42-26.6 % G; 21.4-23.98-26 % A; 19-22.07-25.6 % C;
27.9-29.54-31 % U. 5´ terminus of RNA has a VPg (2/2). Infectivity decreased
when deproteinised with proteases (1/6), or lost when deproteinised with
proteases (5/6); retained when deproteinised with phenol or detergent (12/13),
or lost when deproteinised with phenol or detergent (1/13). Poly A region
present (3/3). Additional factor required for infectivity (1/6), or not required
for infectivity (5/6). Genome has no tRNA-like activity (1/1).
Features of the genome
Non-genomic nucleic acid
found in the virions (5/13), or not found in the virions (8/13); is satellite
RNA (5/5).
Features of proteins
Virion protein(s) one (23/32),
or two (8/32), or three (1/32), or four (1/32); Mr 24000-51580-71000.
Mr of 2nd largest 4000-24170-65000. Mr of 3rd largest
22000-39000-56000. Mr of 4th largest 14300. Virion proteins not
glycosylated (2/2). Virion proteins not phosphorylated (1/1).
Replication
Genome replicates in cytoplasm (2/2).
Replication does not depend on a helper virus (18/18).
Cytopathology
Virions found in cytoplasm (18/21), or in
nuclei (2/21), or in the perinuclear space (1/21), or in Golgi apparatus (1/21),
or in cell vacuoles (5/21). Inclusions present in infected cells (17/20), or
absent from infected cells (3/20); are crystals in the cytoplasm (1/17), or
amorphous X-bodies (1/17), or membranous bodies (8/17), or viroplasms (1/17),
or unusual in shape (12/17); they contain virions (12/13), or they do not
contain virions (1/13).
Taxonomy and
relationships
Viral family : Comoviridae.
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: 20th August 1996.' URL
http://biology.anu.edu.au/Groups/MES/vide/
Dallwitz (1980)
and
Dallwitz, Paine and Zurcher (1993)
should also be cited.
Please send comments, corrections and suggestions to:
vide-manager@biology.anu.edu.au
