The Fate of Tobacco Mosaic Virus Introduced into Tobacco Leaves

Abstract

³²P-labeled TMV was inoculated onto tobacco leaves. At times after inoculation, the leaves were homogenized and the homogenate was fractionated into precipitates of 600g centrifugation (P1), of 15, 000g centrifugation (P2), of 105, 000g centrifugation (P3), and acid-insoluble (P4), acid-soluble (S) fractions of the supernatant. The radioactivity in P3 fraction increased and that in P1 fraction decreased until 6 hours after inoculation, then the former decreased while the latter increased. RNase treatment of the homogenate showed the same radioactive distribution among fractions as that in nontreatment. The radioactivity in S fraction, though the amount was small, was higher during 6 hours after inoculation than that of later stages. The fate of TMV immediately after the introduction into host cells is discussed.