Figure 1.
Current concepts of how drought increases the generation of ROS in photosynthesis. A, Cartoon of leaf section in well-watered plants in which relatively high intercellular CO2 concentrations (Ci) allow efficient regeneration of terminal oxidants and limit RuBP oxygenation. B, Drought-induced stomatal closure restricts CO2 uptake, favoring photorespiratory production of H2O2 in the peroxisome (1) and possibly favoring production of superoxide and H2O2 (2) or singlet oxygen (3) by the photosynthetic electron transport chain. PGA, 3-Phosphoglyceric acid. [See online article for color version of this figure.]