RNAs 1 and 2 of Alfalfa mosaic virus, expressed in transgenic plants, start to replicate only after infection of the plants with RNA 3.
RNAs 1 and 2 of the tripartite genome of Alfalfa mosaic virus (AMV) encode the two viral replicase subunits. Full-length DNA copies of RNAs 1 and 2 were used to transform tobacco plants (R12 lines). None of the transgenic lines showed resistance to AMV infection. In healthy R12 plants, the transcripts of the viral cDNAs were copied by the transgenic viral replicase into minus-strand RNAs but subsequent steps in replication were blocked. When the R12 plants were inoculated with AMV RNA 3, this block was lifted and the transgenic RNAs 1 and 2 were amplified by the transgenic replicase together with RNA 3. The transgenic expression of RNAs 1 and 2 largely circumvented the role of coat protein (CP) in the inoculum that is required for infection of nontransgenic plants. The results for the first time demonstrate the role of CP in AMV plus-strand RNA synthesis at the whole plant level.
Thole
Vera
V
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
Garcia
Maria-Laura
ML
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
van Rossum
Clemens M A
CMA
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
Neeleman
Lyda
L
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
Brederode
Frans T
FT
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
Linthorst
Huub J M
HJM
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
Bol
John F
JF
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands1.
D017794:Alfalfa mosaic virus / Q000235:genetics / Q000502:physiology*; D015152:Blotting, Northern; D002213:Capsid / Q000032:analysis / Q000235:genetics; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D012367:RNA, Viral / Q000032:analysis; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism; D014026:Nicotiana / Q000821:virology; D014158:Transcription, Genetic; D014779:Virus Replication
D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase