Some Properties of Infective Preparations made by Disrupting Tobacco Rattle Virus with Phenol

SUMMARY: Preparations made by treating tobacco rattle virus with phenol were about 5% as infective as the initial virus suspensions when assayed on French bean, but less on tobacco. Virus nucleic acid seems to be a major constituent of such preparations. By contrast with whole virus, nucleic acid preparations lost infectivity when incubated for 20 min. with 0·02 mg. ribonuclease/1. or when stored for a day at 20°. Nucleic acid preparations contain threads about 1 mμ in diameter but very few or no virus rods. The infectivity of nucleic acid preparations was little affected by highspeed centrifugation for periods in which more than 95% of whole virus was sedimented. Ultraviolet-irradiated nucleic acid preparations were photoreactivable although irradiated preparations of whole virus were not. Nucleic acid preparations were only infective when made from purified virus suspensions or from frozen and clarified saps when these contained infective rod-shaped particles 179—192 mμ long. Phenol treatment of purified non-infective particles 73–77 mμ long yielded non-infective preparations.