Abstract
(1) The nucleic acid is isolated from stunt virus-infected rice plant according to the procedure of Figure 1, and it can safely be called ribonucleic acid with high purity and homogenity from the chemical and physicochemical point of view.
(2) The leafhopper, Nephotettix bipunctatus cincticeps UHLER, treated with the RNA preparation becomes viruliferous more efficiently, and consequently the RNA is confirmed of biological activity.
(3) These findings may lead us to the conclusion that the RNA is the substance controlling virus multiplication and the presence of the intact RNA is a necessary condition for virus infectivity.
