Fig. 3. Ipt3 and Ipt4 are required for resistance to nitrate inhibition of nodulation.

A Images of nodules developed in the absence and presence of 5 mM KNO₃ at 14 dpi with M. loti on the indicated host genotypes. Scale bar = 500 μM. B–D Development of total (B), mature (C) and the proportion of mature nodules (D) in the absence and presence of 5 mM KNO₃ at 14 dpi with M. loti. E Nitrogenase activity assessed by Acetylene Reduction Assay (ARA) at 21 dpi with M. loti in the absence and presence of 5 mM KNO₃. Box plots show Min, Q1, Median, Q3, Max and outlier values in nodulation assays (B–D). Significant differences among different genotypes and nutrient conditions are indicated by letters (p < 0.05) as determined by ANOVA and Tukey post-hoc testing with pairwise P-values available in the Source Data file. For ARA (E), bars show mean ± SE and significant differences between Gifu and mutants are indicated by the annotated P values as determined by Student’s t test. The n values of each group are shown.