Studies on Phosphorylase and Q-enzyme Activities in Non-glutinous and Glutinous Rice Varieties.

Abstract

In this experirnent, the authors determined the activities of phosphorylase and Q-enzyme in non-glutinous and glutinous rice varieties, in order to find the relations between the activities and the starch formation. Especially the difference of both enzyme activities was carefully tested among various organs of plants. The results were summarized as follows: 1) Changes in the phosphorylase activity which was determined by the histochemical method, did not show any difference among embryos of varietal seeds placed in bed (Fig. 1). It was also ascertained that changes of the same activity in leaves of plants under various treatments, i.e. supplied with topdressing of N., irrigated with cold water and shaded, showed the similar trend, notwithstanding non-glutinous and glutinous (Fig. 4). But at the various stages before the 12th leaf appeared, the activity in leaves was higher in glutinous plants than that of non-glutinous ones (Fig. 2). The activity shown in the daytime dropped after the same period (Fig. 3). 2) Q-enzyme activity was determined, following a method given by Gilbert, with such parts as boot leaf, endosperm and chaff of both varieties. No appreciable difference of the activities in both of endosperm and leaf existed between those varieties (Fig. 5). The activity was however higher in chaff of the glutinous grains as compared with non-glutinous ones (Fig. 6). 3) Fram these facts, it was inferred that the higher activity of phosphorylase in leaf and of Q-enzyme in chaff might be closely connected with the formation of the starch of amylopectin type in glutinous rice kernels.