Akio Fujiwara

The content of thiamine in germfree plants and biosynthesis of thiamine in vivo in germfree leaves under gnotobiotic conditions

Abstract The thiamine content and growth of radish and Bashona plants by hydroculture were investigated under both gnotobiotic and conventional conditions. The fresh weight of germfree plants at the period of 20 days growth after transplanting was larger than that of conventional plants, and the fresh weight of Hashona was much larger than that of radish plants in either conventional or germfree conditions at 20th day after transplanting. The thiamine content in a Bashona plant under gnotobiotic conditions was equal to that under conventional conditions, but concentration of thiamine in green leaves of radish plants under conventional conditions was twice as much as that under germfree conditions. This experiment suggests that thiamine content of radish under conventional conditions was increased by coexisting microorganisms. The thiamine content in roots for both type of plants was of the order of 15% or less compared with that in green leaves under both conditions. Biosynthesis of thiamine by thiamine p...

The deficiency symptom of microelements on rice plant

Abstract As the rice plant is usually cultured, in practice, on a waterlogged field associated with heavy irrigation, it could be supposed that the rice plant may be supplied with a sufficient amount of microelements and rarely suffers from a lack of them.

GLUTAMATE DEHYDROGENASE IN HIGHER PLANTS III. : Existence of NADPH-linked Glutamate Dehydrogenase

Abstract The occurrence of NADPH-dependent glutamate dehydrogenase (GDH) was studied in higher plants. All of the higher plants tested had both NADH- and NADPH-dependent GDH activities, based on the following observations: 1) NADPHdependent GDH activity was found in the extracts of corn and soybean leaves, which was free of NADPH-dehydrogenase by heat treatment or DEAE-cellulose column chromatography. 2) Radish leaves and roots grown under germ-free condition showed the same NADPH-dependent GDH activity as those grown under conventional condition. 3) No conversion of NADPH to NADH in the reaction mixture was demonstrated by measuring alcohol dehydrogenase activity. Moreover, it was ascertained that rice plant cells grown on suspension culture had 50% of NADPH-dependent GDH activity, and both activities were not affected by nitrogen sources.

Metabolism of acetate-1-14C in rice leaves

Abstract The presence of large quantities of non-volatile organic acids which are members of the TCA cycle has been found in a variety of plant materials. It is now generally accepted that these acids serve as respiratory substrates and the TCA cycle participates in the metabolism of these substances in plant tissues.