Abstract
The localization and quantity of inorganic phophorus in rice kernel during ripening were measured by histochemical method. Inorganic phosphorus is localized mainly in a special protoplast structure which we termed "phosphorus body", not in the amyloplast itself. The amount of this phosphorus was largest at the stage of yellow ripeaing, in which the highest accumulation of starch is performed. The amount of this phosphorus decreases again after this stage. Conversely, some other kind of phosphorus, probably polyphosphate, is highly accumulated in the aleurone layer. Based on the results mentioned adove, an hypothesis regarding the behavior of phosphorus in rice kernel during ripening was presented : when starch is synthesized by phosphorylase, the liberated inorgaic phosphorus is trapped temporarily in the phosphorus body, and accumulated in the aleurone layer as a form of polyphosphate.
