FIG 5.

Induction of iac and cat promoter activities from Paraburkholderia phytofirmans PsJN and derivative mutants by mixtures of indole-3-acetic acid (IAA) and dioxindole-3-acetic acid (DOAA) or compounds X and Y. β-Galactosidase activity levels obtained from transcriptional fusions of iacA, iacC, iacF, iacG, and catB genes exposed to IAA, DOAA, compounds X and Y or mixtures of IAA plus DOAA or compounds X and Y in the wild-type strain (A) and in the mutant derivatives defective in iacS, iacR1, or iacR2 (B). Compounds X and Y or DOAA was prepared using 4-fold-diluted supernatants of strain JMP134-iacAG or JMP134iac1 resting cells previously exposed to 1 mM IAA as the only carbon source for 2 h, respectively. Error bars indicate the standard deviations. WT, wild type; NI, noninduced. Different letters and asterisks indicate statistically significant differences between treatments (one-way analysis of variance, P < 0.05; Tukey's test, P < 0.05; Student's t test, P < 0.05).