Changes in Levels of Nicotinamide Adenine Nucleotides and Krebs Cycle Intermediates in Mung Bean Leaves after Illumination

Changes in levels of nicotinamide adenine nucleotides were measured during a short (30 min) period of illumination following a dark period. Two phases in the time course were found. In the first phase, during the first minute of illumination, a rapid decline in oxidized nicotinamide adenine dinucleotide occurred which represented a net loss of nicotinamide adenine nucleotide. In the subsequent, second phase during illumination, a slower decline in oxidized nicotinamide adenine dinucleotide was found which was coincident with increases in nicotinamide adenine dinucleotide phosphate(s). The changes in the reduced nicotinamide adenine nucleo· tides were relatively small during illumination.