Fig. 2. ipt3 and ipt4 mutants show reduced root iP content in high nitrate conditions.

A, B Cytokinin iP (A) and tZ (B) free base content analysed in mock or 2 days post inoculation with M. loti in the absence and presence of 5 mM KNO₃ using the same root tissue as illustrated in Fig. 1A. Bars show mean ± SE for the n value shown on each bar. Significant differences between nitrate presence and absence conditions as determined by Wilcoxon rank-sum test are indicated by the annotated P values.