Figure 3.

Na⁺ sensitivity of growth rate in sos1 and sos2 seedlings depends on [K⁺] of the medium. With 1 mm KCl present in the medium, the growth rate of sos1 seedlings is greatly impaired by the presence of 50 mm NaCl. The growth rate of sos2 seedlings is impaired to a lesser extent, and the wild type is not affected by this salt treatment. Providing 10-fold more K⁺ (right) increased the growth rate of sos1 seedlings, indicating their growth rate in the presence of 50 mm Na⁺ is limited by K⁺ availability. Each value plotted represents the mean of 3 independent trials ±se, with each trial involving 24 seedlings.