Fig. 4

Knockout of STK increased salt sensitivity in rice. A Phenotype of WT, KO1 and KO3 rice plants under salt stress at seedling stage. For STK-KO plants, 15-d-old seedlings were treated with 140 mM NaCl for 12 d and recovery 4 d. B Survival rates of WT, KO1 and KO3 in (A) after 4 d of recovery. C Chlorophyll content in leaves of 15-d-old plants treated with 100 mM NaCl for 7 d. D MDA concentrations in leaves of 15-d-old plants after 100 mM NaCl treatment for 24 h. E Relative ion leakage in leaves of 15-d-old plants after 100 mM NaCl treatment for 24 h. F–H Ion content in shoots of 4-week-old plants after 6 d of salt stress (100 mM NaCl). Wild type and STK-KO plants were exposed to salt stress (100 mM NaCl) for 6 d and the shoots were harvested for analysis of ion content. The Na⁺ and K.⁺ contents in seedlings were detected as previously described (Schmidt et al. 2013). Data in (B) to (H) are presented as mean ± SD (n = 3, **P ≤ 0.01, Tukey’s test)