Figure 5.

Comparison of the symbiotic properties of P. vulgaris (bean) plants inoculated with different P. phymatum wild-type and mutant strains: wild-type (wt) and the respective nifA, rpoN, cyoB mutants, as well as a nalidixic acid-resistant wild-type strain (NAL) and the respective ΔcyoAB mutant. Number of nodules per plant (A), dry weight per nodule (B), relative nitrogenase activity (C), and nitrogen content (D) were quantified 21 dpi. Here, the combined results of at least two independent experiments are shown. Error bars indicate the standard error of the mean (SEM). For each histogram, values with the same letter are not significantly different (as assessed with ANOVA, Tukey’s test with p-value ≤ 0.05). Histograms after the grey dashed line were analyzed by an unpaired student t-test (p-value ≤ 0.05); the values with the same letter are not statistically significant.