Isometric virus-like particles encapsidate the double-stranded RNA found in Puccinia striiformis, Puccinia recondita, and Puccinia sorghi

Abstract

Isolates of Puccinia striiformis (wheat stripe rust), Puccinia recondita (wheat leaf rust), and Puccinia sorghi (maize rust) contain complexes of double-stranded RNA. In each species, there are at least 12 double-stranded RNAs ranging in size from 150 to 5000 base pairs, and the number, size, and quantitative relationships between the double-stranded RNAs are distinctive for a given species. Most, if not all, of the double-stranded RNAs in each species can be extracted from isometric virus-like particles of 40 nm in diameter purified by sucrose and (or) Cs2SO4 gradients. The data indicate that in these three species of Puccinia the double-stranded RNAs are encapsidated in virus-like particles.