Figure 4.

Adult cipk21 mutant plants are hypersensitive to NaCl and mannitol. A, Rosette leaf stage of mature plants of wild-type (WT), cipk21, and cipk21/CIPK21 plants treated with water (top and third rows), 400 mm mannitol (bottom row), or 300 mm NaCl (second row). B, Quantification of death of stem after 300 mm NaCl and 400 mm mannitol treatment. C, Chlorophyll content of plants treated with NaCl and mannitol. Results depicted in B and C are average values ± se of three independent experiments. Three-week-old plants were treated with 300 mm NaCl and 400 mm mannitol three times after every 3 d. Photographs were taken on the 10th day after treatment. *, Significant differences (one-way ANOVA) between the wild type and cipk21 (P < 0.05) in B and C.