Photodestruction of Chlorophyll inZea mays L. Leaves Under Different CO2 Concentration

Photodestruction of chlorophyll (Chl) inZea mays leaves, after their irradiation with high photon fluence rate (5000 μmol m⁻² s{−1}), was determined in fragments of whole leaves (WL) and also in fraction of mesophyll cells (MC) and bundle sheath cells (BSC) after their mechanical separation. The lag phase and the phase of photooxidation of Chl in MC chloroplasts were shorter than in BSC. Duration of both phases was reduced when the leaves were placed in 0 % CO₂ concentration in the atmosphere, while the increase of CO₂ concentration up to 0.3 % totally protected Chl against photodestruction in BSC within the 9 h experiment. During that period of time Chl was destructed by about 30 % in MC.