Analysis of RNA2 of TRV PaY4 showed it to be recombinant, carrying 3'-terminal sequences derived from RNA1. Virus produced using an infectious cDNA clone of PaY4 RNA2 was nematode transmissible, demonstrating that natural TRV recombinant isolates are not necessarily defective. Mutations introduced into PaY4 RNA2 showed that the 2b gene, but not the 2c gene, is required for transmission by both Paratrichodorus pachydermus and P. anemones nematodes. Experiments examined whether infection of plants with two different virus clones would impact upon nematode transmission of either virus. Simultaneous inoculation with TRV clones expressing green or red fluorescent proteins revealed that mixing of the two virus populations did not occur, although, in roots, adjacent cells were found containing green- or red-tagged viruses. Subsequently, in similar experiments it was found that a TRV PaY4 2b mutant was transmitted when combined with wild-type TRV PaY4. Also, transmission of a 2b mutant of an in vitro TRV/PEBV recombinant virus (TRV-C1) occurred after coinfection with wild-type virus. Thus, the tobravirus 2b transmission protein is trans-acting. Although TRV PaY4 and TRV PpK20 are both transmitted by P. pachydermus, a 2b mutant of TRV PaY4 was not transmitted when coinoculated to plants with TRV PpK20.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1006/viro.2000.0677 | DOI Listing |
Arch Virol
November 2006
Gene Expression Programme, Scottish Crop Research Institute, Invergowrie, Dundee, U.K..
The specificity of the interaction between the coat protein (CP) and 2b nematode-transmission helper protein of two isolates, PpK20 and PaY4, of Tobacco rattle virus (TRV) that differ in their transmission characteristics was investigated. Yeast two-hybrid experiments identified a central domain of the CP that promoted CP:CP interaction but inhibited CP:2b interaction. Deletion of a conserved coiled-coil domain from the 2b protein prevented its interaction with CP, whereas deletion of N- and C-terminal domains of the 2b protein greatly enhanced its interaction with CP.
View Article and Find Full Text PDFVirology
August 2002
Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, United Kingdom.
Transmission of the tobraviruses Tobacco rattle virus (TRV) and Pea early-browning virus (PEBV) by trichodorid vector nematodes requires the viral coat protein (CP) and the 2b protein, a nonstructural protein encoded by RNA2, the smaller of the two viral genomic RNAs. It is hypothesized that the 2b protein functions by interacting with a small, flexible domain located at the C-terminus of the CP, forming a bridge between the virus particle and the internal surface of the vector nematode feeding apparatus. Antibodies specific for the 2b protein of PEBV or TRV did not bind to virus particles that were adsorbed to electron microscope grids and were not able to trap virus particles from extracts of infected plants.
View Article and Find Full Text PDFVirology
January 2001
Department of Pathology, Scottish Crop Research Institute, Dundee, Invergowrie, DD2 5DA, United Kingdom.
Analysis of RNA2 of TRV PaY4 showed it to be recombinant, carrying 3'-terminal sequences derived from RNA1. Virus produced using an infectious cDNA clone of PaY4 RNA2 was nematode transmissible, demonstrating that natural TRV recombinant isolates are not necessarily defective. Mutations introduced into PaY4 RNA2 showed that the 2b gene, but not the 2c gene, is required for transmission by both Paratrichodorus pachydermus and P.
View Article and Find Full Text PDFVirology
October 1999
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden, 2300 RA, The Netherlands.
DI7 is a defective interfering RNA derived from RNA 2 of tobacco rattle tobravirus (TRV) isolate PpK20. Tobacco was transformed with DI7 cDNA fused to the CaMV 35S promoter. Upon infection of the transgenic plants with TRV isolate PpK20 or the serologically unrelated isolate PaY4, the transgenic DI7 RNA started to accumulate at high levels and strongly interfered with accumulation of wild-type (wt) RNA 2.
View Article and Find Full Text PDFJ Virol Methods
January 1996
Department of Virology, Scottish Crop Research Institute, Invergowrie, Dundee, UK.
A rapid method was developed using long template (LT)-PCR to amplify the complete RNA2 of isolates of TRV for which no sequence data are available. The amplification makes use of a 5' terminal oligonucleotide which contains degeneracies corresponding to the sequences of several different TRV isolates, and a 3' oligonucleotide which is complementary to a sequence present in all known isolates. This method was used to show the high degree of sequence homology existing in the terminal regions of two uncharacterised TRV isolates (TPO3 and PAY4), and revealed the deletion of an 80-nucleotide sequence in the 5' terminal region of TPO3 RNA2.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!