Prior illumination and the respiration of maize leaves in the dark.

The course of respiration of attached maize (Zea mays L.) leaves was measured by infrared gas analysis of CO(2) efflux in the dark following illumination in atmospheres of 300 microliters of CO(2) per liter of air, CO(2)-free air, and CO(2)-free N(2) containing 400 microliters of O(2) per liter. CO(2) efflux from control leaves started 3 to 4 minutes after darkening, increased to a maximum after about 20 minutes, and returned to a steady minimum after 2 to 3 hours. Respiration was quantitatively related to prior illumination, independent of net CO(2) fixation in the light, and depressed by N(2). Light, but not air, was required to produce a substrate for respiration in the subsequent dark period; air was required for oxidation of the substrate to CO(2). The stimulation of respiration by prior illumination in maize leaves differs in its slower onset and greater duration from the postillumination burst of photorespiration.