Plant Viruses with Circular Single-Stranded DNA

Abstract

SMALL quasi-isometric particles, mostly occurring in pairs, have been found in, and purified from extracts of plants infected by maize streak 1, beet curly top, tomato golden mosaic", euphorbia mosaic", bean golden (yellow) mosaic3 -5, cassava latent6 and cassava brown streak viruses Individual particles are 15-20 nm in diameter-unusually small for a virus-and in electron micrographs many of the individual particles in the pairs have a five-sided outline in which the contiguous sides seem longer than the others.