Fig. 5

AMT1;1-T460 phosphorylation is reduced in cipk15 mutant plants. Plant seedlings were germinated and grown for 7 days in half-strength MS medium with 5 mM KNO₃ as the sole nitrogen source, then starved for 2 days in half-strength MS medium without nitrogen. Seedlings were treated with 1 mM NH₄Cl for 1 h, membrane fractions were isolated and probed with anti-AMT1-P antibodies (a) and anti-AMT1;1 antibodies (b) [25]. Ponceau S staining served as a loading control. Quantification of phosphorylation of AMT1-P levels normalized to Ponceau S staining and relative to wild-type shown in c. Corresponding data and replications were obtained in three independent experiments. Data (c) are the mean ± SD for three experiments. p, significant change compared to wild-type as shown in figure (two-way ANOVA followed by Tukey’s post-test)