Soil-borne wheat mosaic virus protein interactions with wheat streak mosaic virus cylindrical inclusions

Abstract

Cylindrical inclusions (CI) of wheat streak mosaic virus (WSMV) became labeled with antibody to soil-borne wheat mosaic virus (SBWMV) in thin sections of wheat leaf cells infected with both viruses. Either the capsid protein or one of the other two proteins coded by RNA II of SBWMV must bind to the WSMV inclusion body. However, the WSMV inclusions did not become labeled with antibody to SBWMV in leaf cells with a mixed infection of WSMV and an RNA II deletion mutant of SBWMV. The deleted RNA II codes for capsid (19.7K) and 28K proteins, but not for the 90K protein found with wild-type SBWMV infections. All three proteins react with antibodies to virions. It is tentatively concluded that the 90K protein of SBWMV binds to WSMV inclusion bodies in cells infected with both viruses. Fewer WSMV cylindrical inclusions were aligned penpendicular to cell walls in cells with mixed infections and in which the inclusions were labeled with SBWMV antibody than in either singly or doubly infected cells where the inclusions did not become so labeled.