Tissue of crisphead lettuce (Lactuca sativa L.) was kept in air or air enriched with 5% to 20%
CO 2 at 0° C for 2 to 9 days followed by transfer to air or the CO 2-enriched atmosphere at
20° C for 1 day to study the mode of CO 2 action on metabolism of organic and amino acids.
Exposure to 20% CO 2 reduced the extractable activity of succinate dehydrogenase. The
20% CO 2 treatment caused a decrease in pH, which partially inhibited the catalytic activity
of succinate dehydrogenase and substantially activated glutamate decarboxylase. As a …