Figure 3.

Stomatal responses to Ca in the dark. A, Stomatal conductance in intact leaves of Arabidopsis. B, Stomatal conductance in intact leaves of A. capillus-veneris. Leaves were held in a leaf chamber for 1 h under darkness at a CO₂ concentration of 350 μL L⁻¹ and then exposed to low (0) and high (1,200 μL L⁻¹) concentrations of CO₂ by changing the concentration in the chamber. Dotted lines show the CO₂ concentration in the chamber. C, Relationship between Ca and Ci (white circles) and stomatal conductance (black circles) in the range of 0 to 1,200 μL L⁻¹ Ca. The dotted line represents the linear relationship between Ca and Ci.