Figure 5.

Auxin influences the germination of the ntm2-1 seeds under high salinity. A, Effects of auxin on the germination of Ler seeds. Seeds were cold imbibed and germinated on MS-agar plates supplemented with varying concentrations of IAA. Germination assays were carried out as described in Figure 4B. B and C, Effects of auxin on the germination of ntm2-1 seeds under high salinity. Seeds were cold imbibed and germinated on MS-agar plates supplemented with 1 mm IAA and varying concentrations of NaCl (B) or on MS-agar plates supplemented with 150 mm NaCl and varying concentrations of IAA (C). Germination assays were carried out as described in Figure 4B, except that germination percentages were calculated 2 d after cold imbibition. Error bars indicate se. Statistical significance was determined by Student’s t test (* P < 0.01). S100 and S150, NaCl at 100 mm and 150 mm, respectively. In C, germination percentages were calculated relative to those on NaCl at 150 mm without auxin. D, Effects of auxin and salt on DR5-GUS expression. Cold-imbibed seeds of DR5-GUS plants were allowed to germinate for the indicated time periods on MS-agar plates supplemented with 10 μm IAA or 150 mm NaCl or both. Germinating seeds at similar germination stages were subjected to GUS staining. E, Effects of auxin on ntm2-1 seedling growth under high salinity. Seedlings were grown for 2 weeks on MS-agar plates supplemented with 10 μm IAA or 100 mm NaCl or both. Bar = 10 mm.