Abstract
The inhibitory effect of actidione and thiouracil against TMV production in tobacco leaf disks have been reported (Shimomura and Hirai, 1959). When these antiviral substances were applied to infected tissues and the amount of virus produced was determined by the optical densities, the inhibitory effect was much less pronounced than that determined by the infectivity tests (local lesion method) (Shimomura, Nishikawa and Hirai, 1957). In the present report, the paper electrophoretic pattern of TMV protein produced in the presence of these antiviral substances are presented.
The soluble protein of infected leaf tissues was obtained by 0.6 saturated ammonium sulphateprecipitation and by its dissolution with the buffer of McIlvaine and Lillie (pH7.0). These protein was run on filter paper for 3 hours using Toyoroshi No. C electrophoretic apparatus and veronal buffer (pH 8.5, ionic strength 0.045). Potential of 400V was applied to give 0.5mA/cm. The results were consistent with those obtained by Kanngiesser (1955) and both healthy protein and virus protein were separately detected on filter paper. The virus protein, which was purified by repeated cycles of ammonium sulphate-precipitation and dissolution and again precipitation at the isoelectric point of the virus, remained almost at the origin even after 3 hours' run and showed only one peak. In contrast, the virus protein, produced in the presence of actidione or thiouracil, showed two distinct peaks. The problem whether these two fractions, shown by electrophoretic pattern, represent infective virus and noninfective virus is now under study, although existence of two types of virus in the infected tissues treated with antiviral substances has been proposed by Francki (1959-62).
