Polycistronic Translation of Plant Viral Ribonucleic Acid

Abstract

Polysomes specific for tobacco mosaic virus (TMV) infection were analyzed. Two to three days after inoculation of tobacco leaves with, TMV, polysomes of the large size, synthesizing TMV.antigenic protein were observed. Molecular weight of TMV-antigenic protein found under these conditions ranged from 2×104 to 6-8×104 daltons which might represent coat protein subunit and its trimer. Studies on the structure of polysomes hearing infecting RNA as messenger suggested that cistrons near the 3'-end of TMV-RNA was translated at first immediately after infection. These results favored the concept of a polycistronic translation of plant viral RNA, in contrast to a monocistronic translation observed in the mammalian system.