Nature of Genome:
General Host Type:
Morphology:
|
ssRNA
Plants
unencapsidated ssRNA |
Distiguishing Features
A circular ssRNA between 246 and 250 nt depending on isolates and sequence variants. It is unique in having a base composition rich in A+U (62%) in contrast to the other viroids which are rich in G+C (53-60%). The most stable secondary structure is a rod-like or quasi-rod-like conformation in which neither five domains nor a central conserved region (CCR) can be distinguished. It is soluble in 2 M LiCl as are typical viroids like Potato spindle tuber viroid (PSTVd), Apple scar skin viroid (ASBVd) and Coleus blumei viroid 1 (CbVd-1) having also rod-like or quasi-rod-like most stable secondary structures. Plus and minus strands of Avocado sunblotch viroid (ASBVd) can form hammerhead structures. Because both single hammerhead structures of ASBVd are thermodynamically unstable, double hammerhead structures have been proposed to operate in the selfcleavage reactions, especially in that of the plus polarity RNA (Fig. 3). Replication occurs through a symmetric rolling-circle model since the minus circular monomer has been found in infected tissue. ASBVd accumulates and replicates in chloroplasts.
List of Species Demarcation Criteria in the Genus
Not applicable.
List of Species in the Genus
The ICTVdB viroid code and the viruses. Official viroid species names are in italics. Tentative viroid species
names, alternative names ( ), isolates, strains, serotypes, subspecies, or rejected names are not italicized.
viroid codes, viroid names, genome sequence accession numbers [ ] and assigned abbreviations ( ), are:
Species, their serotypes, strains and isolates
80.002.0.01.001. | Avocado sunblotch viroid |
| |
80.002.0.01.001.00.001. | Avocado sunblotch viroid | [J02020] | (ASBVd) |
Tentative Species in the Genus
None reported.
Genus |
80.002.0.02. Pelamoviroid |
|
Type Species |
80.002.0.02.001. Peach latent mosaic viroid |
|
List of Species Demarcation Criteria in the Genus
An arbitrary level of less than 90% sequence similarity and distinct biological properties, particularly host range, currently separates species within genera.
List of Species in the Genus
The ICTVdB viroid code and the viruses. Official viroid species names are in italics. Tentative viroid species
names, alternative names ( ), isolates, strains, serotypes, subspecies, or rejected names are not italicized.
viroid codes, viroid names, genome sequence accession numbers [ ] and assigned abbreviations ( ), are:
Species, their serotypes, strains and isolates
80.002.0.02.002. | Chrysanthemum chlorotic mottle viroid |
| |
80.002.0.02.002.00.001. | Chrysanthemum chlorotic mottle viroid | [Y14700] | (CChMVd) |
80.002.0.02.001. | Peach latent mosaic viroid |
| |
80.002.0.02.001.00.001. | Peach latent mosaic viroid | [M83545] | (PLMVd) |
80.002.0.02.001.00.002. | Peach latent mosaic viroid - apple |
| (PLMVd-app) |
80.002.0.02.001.00.003. | Peach latent mosaic viroid - apricot |
| (PLMVd-apr) |
80.002.0.02.001.00.004. | Peach latent mosaic viroid - cherry | [AF339741] | (PLMVd-che) |
80.002.0.02.001.00.005. | Peach latent mosaic viroid - pear | [AF339740] | (PLMVd-pea) |
80.002.0.02.001.00.006. | Peach latent mosaic viroid - plum | [AF339742] | (PLMVd-plu) |
Tentative Species in the Genus
None reported.
List of Unassigned Viroids in the Family
List of Species in the Genus
The ICTVdB viroid code and the viruses. Official viroid species names are in italics. Tentative viroid species
names, alternative names ( ), isolates, strains, serotypes, subspecies, or rejected names are not italicized.
viroid codes, viroid names, genome sequence accession numbers [ ] and assigned abbreviations ( ), are:
Species, their serotypes, strains and isolates
80.002.0.00.002. | Blueberry mosaic viroid-like RNA |
| |
80.002.0.00.002.00.001. | Blueberry mosaic viroid-like RNA |
| (BluMVd-RNA) |
80.002.0.00.003. | Burdock stunt viroid |
| |
80.002.0.00.003.00.001. | Burdock stunt viroid |
| (BuSVd) |
80.002.0.00.004. | Eggplant latent viroid |
| |
80.002.0.00.004.00.001. | Eggplant latent viroid |
| (ELVd) |
80.002.0.00.005. | Nicotiana glutinosa stunt viroid |
| |
80.002.0.00.005.00.001. | Nicotiana glutinosa stunt viroid |
| (NGSVd) |
80.002.0.00.006. | Pigeon pea mosaic mottle viroid |
| |
80.002.0.00.006.00.001. | Pigeon pea mosaic mottle viroid |
| (PPMMoVd) |
80.002.0.00.007. | Tomato bunchy top viroid |
| |
80.002.0.00.007.00.001. | Tomato bunchy top viroid |
| (ToBTVd) |
Similarity with other Taxa
None reported.
Derivation of Names
Avsun: sigla avocado sunblotch viroid.
Pelamo: sigla from peach latent mosaic viroid.
Viroid: from the name given to the subviral agent of potato spindle tuber disease.
References
Collated from VIIIth ICTV Report
Contributed by
Flores, R., Randles, J.W., Owens, R.A., Bar-Joseph M. and Diener, T.O.
Cite this publication as: Index of Viruses - Avsunviroidae (2006). In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C (Ed), Columbia University, New York, USA. http://www.ncbi.nlm.nih.gov/ICTVdb/Ictv/fs_index.htm
Version 4 is based on Virus Taxonomy, Classification and Nomenclature of Viruses, 8th ICTV Report of the International Committee on Taxonomy of Viruses. Fauquet, CM, Mayo, MA, Maniloff, J, Desselberger, U, and Ball, LA (EDS) (2005) Elsevier/Academic Press, pp. 1259.
Additional References
Reference List from the 8th ICTV Report
ICTVdB taxon description
ICTVdB Picture Gallery
References to sequence databases at GenBank and PubMed Central:
PubMed Central References;
nucleotide sequences;
complete genomes
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