Figure 10.

Interactions between the endosomal and vacuolar antiporters. A, The quadruple mutants. The quadruple mutants kea4 kea5 kea6 nhx1 and kea4 kea5 kea6 nhx2 were grown on 1/2 MS medium for 4 d, then the seedlings were transferred to 1/2 MS medium containing 0, 100, and 150 mm NaCl. Photographs were taken at 10 d under salt stress. Bars = 1 cm. B, Inhibition of root growth for seedlings from A (mean ± se; n = 8 seedlings). C, Overexpression lines. The overexpression lines kea4 kea5 kea6/NHX1 and kea4 kea5 kea6/NHX2 were grown on 1/2 MS medium for 4 d, then the seedlings were transferred to 1/2 MS medium containing 0, 100, and 150 mm NaCl. Photographs were taken at 10 d under salt stress. Bars = 1 cm. D, Inhibition of root growth for seedlings from C (mean ± se; n = 8 seedlings). E, pH measurement. pH of the Golgi, TGN, PVC/MVB, and vacuole in quadruple mutants and overexpression lines was determined (mean ± se; n ≥ 20 protoplasts). The method was the same as in Figure 8. F, Vacuolar pH of the mature root measured by BCECF-AM (mean ± se; n = 10 seedlings). The method was the same as in Figure 8. In E and F, statistics by Student’s t test are shown: *, P < 0.05 and **, P < 0.01.