Molecular Weight of the Infective RNA from Leaves Infected with Carrot Mottle Virus

Highly infective nucleic acid preparations were made from Nicotiana clevelandii leaves infected with carrot mottle virus (CMotV). The infective material had the properties of a single-stranded RNA but was less than 1% of the total RNA in the preparations. It had an apparent mol. wt. of about 1.5 to 1.6 × 106 in agarose-polyacrylamide gels and a sedimentation coefficient of about 28 to 30S in linear-log sucrose gradients. The infective RNA did not contain any considerable poly-adenylate sequence, nor did it require an associated protein for infectivity.