RNA synthesis in broadbean leaves infected with broadbean mottle virus

Abstract

Tissue of broadbean leaves infected with broadbean mottle virus (BBMV) was infiltrated with actinomycin D followed by [ 14C]uridine. As shown by velocity sedimentation analysis in sucrose gradients, two major classes of single-stranded RNAs distinct from RNAs of healthy leaf tissue were synthesized under those conditions. Part of the RNA product synthesized in infected leaves was incorporated into virus particles and was analogous to BBMV-RNA. Another class of labeled RNA product sedimented between the light ribosomal RNA and transfer RNA, and was not found in appreciable amounts in newly formed virus particles. This slower-sedimenting class of RNA was not an artifact due to actinomycin D treatment as it was formed also in untreated infected tissue.