Figure 1.

Representative plants of wild-type (WT), sos1, and sos3 mutants that were exposed to high-salt (100 mM NaCl) or low-K⁺ (20 μM K⁺) stresses. Seedlings were grown on vertical MS agar plates for 4 days (root length ≅ 1.5 cm) and then transferred to vertical agar plates containing control (A, MS nutrients), 100 mM NaCl (B, MS + 100 mM NaCl), or modified MS (see Materials and Methods) with 20 μM K⁺ and 0.15 mM (C) or 3 mM Ca²⁺ (D) for 7 days. The growth of both sos1 and sos3 was inhibited by either NaCl (B) or low K⁺ (C). However, the growth of sos3 on low K⁺ was restored by increased Ca²⁺ (D). (Bar = 1 cm.)