Fig. 8 Growth and ion contents of wild-type (WT) and transgenic rice cells overexpressing OsNHX1 grown at various salt concentrations. Wild-type rice cells (lines 97-4-5 and 97-5-15) transformed with pMSH1 and transgenic cells (lines 95-1-35 and 95-5-169) transformed with pMSH1+OsNHX1 were cultured in the presence of 0, 0.1 and 0.2 M NaCl for 14 d. (A) Western blot analysis of the tonoplast fractions isolated from these cells. Protein (7 µg) was separated on a 10% SDS-PAGE gel and immunoblotted with antibodies against the COOH-terminus of OsNHX1. (B and C) Growth of wild-type (white bars; 97-4-5 in B and 97-5-15 in C) and transgenic cells (black bars; 95-1-35 in B and 95-5-169 in C) is shown as % control of dry weight. Each value is the mean ± SD of three independent experiments. Asterisks represent significant differences between the wild-type and transgenic cells (P <0.01, Student’s t test). (D and E) Na⁺ (D) and K⁺ (E) contents of wild-type (white bars; 97-5-15) and transgenic cells (black bars; 95-5-169). Ion contents were determined as shown in Materials and Methods. Each value is the mean ± SD of three independent experiments. Different letters in each graph (a–c in D and a–d in E) indicate significant differences (P <0.05, ANOVA and Tukey’s test). DW, dry weight.