Characterization and genomic analysis of tobacco vein clearing virus, a plant pararetrovirus that is transmitted vertically and related to sequences integrated in the host genome

Citation
Be. Lockhart et al., Characterization and genomic analysis of tobacco vein clearing virus, a plant pararetrovirus that is transmitted vertically and related to sequences integrated in the host genome, J GEN VIROL, 81, 2000, pp. 1579-1585
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF GENERAL VIROLOGY
ISSN journal
0022-1317 → ACNP
Volume
81
Year of publication
2000
Part
6
Pages
1579 - 1585
Database
ISI
SICI code
0022-1317(200006)81:<1579:CAGAOT>2.0.ZU;2-G
Abstract
A previously undescribed caulimo-like virus was identified in the hybrid to bacco species Nicotiana edwardsonii, and was named tobacco vein clearing vi rus (TVCV) after the symptoms associated with its occurrence in this plant. The virions of TVCV are 50 nm in diameter and are composed of a 45 kDa cap sid protein and a 7767 bp dsDNA genome. Each strand of the genome is interr upted by a site-specific discontinuity, In genome sequence and arrangement of ORFs TVCV was most similar to cassava vein mosaic virus, indicating that TVCV is a pararetrovirus, No serological relationship was detected between TVCV and any other caulimoviruses, including petunia vein clearing virus, which has similar biological properties. In N, edwardsonii TVCV was seed-tr ansmitted to 100% of progeny plants, but was not transmitted by mechanical inoculation, grafting or Myzus persicae to any of seven other Nicotiana spp , Genomic DNA of TVCV hybridized to genomic DNA of N, edwardsonii and of N, glutinosa, its male parent, but not to genomic DNA of N, clevelandii, the female parent. TVCV has 78% sequence identity with pararetrovirus-like sequ ences that are present in high copy number in the N, tabacum genome, and TV CV genomic DNA hybridized to genomic DMA of N. tabacum and N, rustica, Thes e observations suggest that the episomal form of TVCV may arise from integr ated pararetroviral elements present in N, edwardsonii, that these integran ts were inherited from the male parent N, glutinosa, and that these element s are related but not identical to pararetroviral elements occurring in oth er Nicotiana spp.