Figure 4. Effects of drought and salt stresses on stomatal conductance, transpiration rate, net photosynthesis and internal leaf CO₂ concentration of wild-type (WT) and AtUCP1 transgenic plants.

Thirty-day-old plants were exposed for 10 days to 200 mM mannitol or 175 mM NaCl and then recovered with pure water for 3 days. A–C: stomatal conductance (gs); D–F: transpiration rate (E); G–I net photosynthesis (A); J–L: internal leaf CO₂ concentration (Ci). A, D, G and J: control treatment. B, E, H and K: 200 mM mannitol. C, F, I and L: 175 mM NaCl. * and ** indicate significant differences relative to the control at P<0.0001 and P<0.001, respectively.