Studies on morphological and physiological changes in apex of rice plant during fioral differentiation. II. Changes in quantity of protein, amino acids and soluble sugar

Abstract

The purpose of this series of study was to get some informations about the physiological process of floral differentiation. In the previous paper the author reported on the distribution of polysaccharides and their changes in quantity in shoot apex during the organogenesis of foliar and floral primordia. In this paper, the distributions of RNA and of protein in shoot apex were investigated histochemically, and the changes in quantity of amir.O acids and soluble sugar (glucose, fructose and sucrose) were determined by means of paper chromatography. The localization of protein in shoot apex and floral bud was almost coincided with that of RNA, and most of those substances were distributed mainly in the regions where polysaccharides were not deposited or a little. In other words, the concentrations of RNA and of protein were high in foliar and floral primordia where the active growth and d.ifferentiation were occurring. The changes in quantity of soluble sugar in shoot apex during the floral differentiation were closely connected with the changes of concentration in polysaccharides reported in the previous paper. The changes of amino acids were also related to those of RNA and protein. According to the facts obtained in this study it may be suggested that the flower bud differentiation and its growth in rice plant proceed from the physiological processes in shoot apex. Namely, the increase in polysaccharides accumulation in the tissue that has meristematic potentiality induces the reduction of their synthetic action, and this causes the tonversion from the active state of polysaccharides synthesis into the state of active protein synthesis and polysaccharides decomposition The same relation was also observed in the stage of vegetative growth and the early stage of generative growth when the shoot apex has already transformed into a young ear.