Immunoprecipitation analysis of potyviral in vitro translation products using antisera to helper component of tobacco vein mottling virus and potato virus Y.

The serological relationships of the products of in vitro translation of the RNA of various potyviruses were analyzed by using antisera to helper component (HC) from tobacco plants infected with either tobacco vein mottling virus (TVMV) or potato virus Y (PVY). The PVY-HC antiserum immunoprecipitated a specific PVY-RNA translation product; this product was not reactive with antisera to PVY-induced cylindrical inclusion protein or capsid protein or to the two tobacco etch virus nuclear inclusion proteins. The antiserum to PVY-HC did not immunoprecipitate significant amounts of any translation products of 16 other potyviruses including TVMV. In contrast the antiserum to TVMV-HC efficiently immunoprecipitated a specific product(s) of four different potyviruses, some isolates of which are poorly transmitted or nontransmissible by aphids, and less efficiently a product(s) from 12 other potyviruses, including PVY. Distinct serotypes were resolved among the major in vitro translation products of 17 different potyviral RNAs by the antisera to TVMV-HC and PVY-HC. There appears not to be a correlation between the serological reactivities of HC-related polypeptides and the ability of different HC-virus combinations to effect aphid transmission of the virus.