Recovery of an Inhibitor of Virus Replication from the Intercellular Fluid of Hypersensitive Tobacco Infected with Tobacco Mosaic Virus and from Uninfected Induced-Resistant Tissue

Abstract

A compound was obtained from the intercellular fluid of tobacco cultivar Samsun NN infected with tobacco mosaic virus (TMV) which inhibited virus replication when applied to TMV-inoculated protoplasts or leaf disks. Based on the criteria of serology, polyacrylamide gel electrophoresis, and molecular weight estimations, the compound from the intercellular fluid was judged to be identical to the inhibitor of virus replication (IVR) obtained previously from TMV-infected Samsun NN protoplasts. The recovery of IVR is faciliated when leaves are used as a source. A similar compound was obtained from systemic induced-resistant tissue of Samsun NN and cultivar Xanthi-nc. The belief that induced resistance results from an activation of the localizing mechanism is supported by this result.