FIGURE 3.

Arabidopsis thaliana root colonization by Bacillus subtilis WT and single ∆rap‐phr mutants. To estimate the impact of each of the Rap‐Phr modules on root colonization, WT and single ∆rap‐phr mutants were inoculated onto five‐day‐old seedlings of A. thaliana (n = 7–10). After 16 h, CFU per mm root length was quantified. The log10‐transformed value of CFU/mm root for each technical replicate was normalized to the mean of the WT from the same experiment. Each dot represents a root, while the mean value for each mutant is displayed as a red horizontal line. The black horizontal line represents the mean of the WT and the SD of the WT from each respective experiment is shown in shaded gray. For each assay, an ANOVA was performed on the log10‐transformed values of CFU/mm root length. When significant (p < 0.05), means were compared via Dunnett's multiple comparison test with WT as the control. When data failed to meet parametric assumptions, a Kruskal–Wallis test was performed followed by a Dunn's test.  **p < 0.005, ***p < 0.001