Construction of a recombinant vaccinia virus which expresses immunoreactive plant virus proteins.

A chimeric transcription unit was assembled consisting of a vaccinia virus promoter linked to a 2400 bp(3) double-stranded complementary DNA (cDNA) made to the 3' end of the genomic RNA of the plant pathogen, tobacco etch virus (TEV). Marker rescue techniques were used to introduce virus recombinant genes into the vaccinia virus genome. The recombinant virus (designated WNAT) was isolated, purified, and subjected to molecular genetic analyses. The ability of WNAT to direct the expression of plant virus genetic information in a mammalian system was assessed by infecting a line of monkey kidney cells. The plant virus cDNA insert was transcribed into RNA molecules that were correctly processed, and subsequently translated into proteins that were recognized by monospecific antisera directed against either the capsid protein or nuclear inclusion protein of TEV. These results are discussed in relation to using vaccinia virus to investigate other aspects of the plant virus replicative cycle.