The Effect of Anaerobiosis on Acids of the Tricarboxylic Acid Cycle in Peas

Maturing seeds of the pea (Pisum sativum) were subjected to 24 hours' anaerobiosis and then returned to air. Carbon-dioxide evolution was estimated. At intervals samples were analysed for their content of organic acids by silica gel and paper chromatography and for bound carbon dioxide. During the anaerobic period there was a large accumulation of lactate, an initial increase of succinate, and a slow, continuing decrease of malate and citrate. On return to air the main changes were a fall in the concentration of lactate and succinate, a rise in malate and acetate, and a rapid rise followed by a fall of pyruvate and α-oxo-glutarate. Comparison of these changes with each other and with the rate of production of carbon dioxide shows that they do not fit a pattern based on the tricarboxylic acid cycle. The possibility that this was the result of a system of ‘pools’ of these acids is considered.