Variation of nicotinamide adenine dinucleotide phosphate level in bean hypocotyls in relation to o(2) concentration.

Slices of hypocotyls from 3-day-old seedlings of Vigna sesquipedalis (L.) Fruwirth in the germination stage were incubated under various gaseous conditions. The NADP+NADPH level in the hypocotyl slices changed with the oxygen tension. A high NADP+NADPH level was observed under aerobic conditions and a low NADP+NADPH level under anaerobic conditions.The 100 x NADH/NAD+NADH ratio increased greatly under anaerobic conditions. In general a low NADP + NADPH level corresponded with a high 100 x NADH/NAD+NADH ratio. On the basis of the results given in the following paper, it was discussed that the slowness of NADH oxidation in hypocotyl tissue due to anaerobic conditions results in the inhibition of NADP formation.The variation of the NADP+NADPH level was considered to produce a modification of the carbohydrate metabolism.The NADP+NADPH level in E. coli cells suspended in glucose solution also changed with the oxygen tension.