Abstract
It was found that TMV inactivated by UV-radiation ray interfered with TMV infection in several kinds of plants when active and inactivated viruses were simultaneously inoculated on these plants. The degree of interference differed with plant species inoculated. The maximum inhibition was induced in Datura stramonium, and the minimum in Nicotiana glutinosa plants. The inhibitory action of the UV-irradiated virus was slightly affected by adjusting the hydrogen-ion concentration of the mixture of active and inactivated viruses at pH 5.2 as it was compared with that at pH 7.0. The infectivity of virus in the mixture was recovered by dilution. Although the virus protein interfered with the establishment of TMV in tobacco plants, the UV-irradiated RNA had no inhibitory action. The juices extracted from the leaves of several Solanaceous plants inoculated with the inactivated TMV had no inhibitory effect against TMV infection when they were mixed with TMV and inoculated on test plants.
