A point mutation in the coat protein abolishes aphid transmissibility of a potyvirus.
A nonaphid transmissible (NAT) variant of tobacco vein mottling virus (TVMV) was used to test the hypothesis that the viral coat protein (CP) plays a role in determining aphid transmissibility. Comparison of the nucleotide sequences in the coat protein cistron of an aphid transmissible isolate (TVMV-AT) with that of TVMV-NAT revealed a single nucleotide difference (G----A) at position 8445; this alters a single amino acid residue (G----E) at position 2747. A cDNA fragment representing the CP region of TVMV-NAT was substituted into the CP region of a full-length cDNA clone of TVMV-AT, and transcribed RNA was inoculated to tobacco plants. Aphids were unable to transmit the resultant hybrid virus which had the TVMV-NAT coat protein, although the concentration and infectivity of the hybrid virus in the source plants were similar to those of TVMV-AT. This is the first direct demonstration that a CP mutation affects aphid transmissibility of a potyvirus.
Atreya
C D
CD
Department of Plant Pathology, University of Kentucky, Lexington 40546.
Raccah
B
B
Pirone
T P
TP
D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000032:analysis; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D009154:Mutation; D010942:Plant Viruses / Q000235:genetics*; D010947:Plants, Toxic; D012045:Regulatory Sequences, Nucleic Acid; D014026:Nicotiana / Q000382:microbiology; D014158:Transcription, Genetic; D014777:Virus Diseases / Q000235:genetics
D004279:DNA, Viral