Figure 7.

Changes in K⁺ homeostasis during stress are necessary for flg22-induced root growth response. A, K⁺ content is reduced during stress. Comparison of K⁺ content in NaCl (300 mm, 8 h) and flg22-treated (1 μm, 15 min) seedlings relative to untreated seedlings (set at 100%, n = 4–20) where * indicates significant difference from the wild type for a given treatment, P < 0.05. B, Flg22-induced root growth inhibition can be rescued by the K⁺ channel blocker TEA. The seedlings were grown for 5 d prior to transfer to modified liquid MS media with 2 mm K⁺ (instead of 20 mm in unmodified MS media) containing no flg22 or 100 nm flg22 supplemented with the indicated concentration of TEA. Primary root length was quantified 10 d after transfer (n = 10–16) where * indicates significant difference from the nonflg22 treatment, P < 0.05.