A cDNA clone from a defective RNA of citrus tristeza virus is infective in the presence of the helper virus.
A naturally occurring defective RNA of 2379 nt (D2.3) from the VT strain of citrus tristeza closterovirus (CTV) was cloned and sequenced. The D2.3 RNA is a fusion of two regions of 1521 and 858 nt from the 5' and 3' ends of the CTV genome, respectively. A cDNA clone of D2.3 RNA was tagged by the insertion of a 0.47 kb chimeric DNA fragment and the recombinant cDNA was inserted downstream of the cauliflower mosaic virus 35S promoter. The resulting construct was bombarded into CTV-infected tissue, which was then grafted onto virus-free plants. The presence of recombinant RNA in systemically infected leaves was demonstrated by RT-PCR. Sequencing the RT-PCR products synthesized from double-stranded RNA confirmed the presence of the chimeric segment used for tagging. This is the first report of an infectious cDNA molecule derived from CTV D-RNA.
Yang
G
G
S. Tolkowsky Laboratory, Department of Virology, A.R.O., Volcani Center, Bet Dagan, Israel.
Mawassi
M
M
Ashoulin
L
L
Gafny
R
R
Gaba
V
V
Gal-On
A
A
Bar-Joseph
M
M
D001483:Base Sequence; D002957:Citrus / Q000821:virology; D003001:Cloning, Molecular; D017790:Closterovirus / Q000235:genetics / Q000472:pathogenicity*; D018076:DNA, Complementary; D004279:DNA, Viral / Q000502:physiology*; D003673:Defective Viruses / Q000235:genetics / Q000472:pathogenicity*; D006378:Helper Viruses / Q000502:physiology*; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000502:physiology*
D018076:DNA, Complementary; D004279:DNA, Viral; D012367:RNA, Viral