Extended Data Fig. 2: Siderophore production of defined siderophore producers (WT), their isogenic non-producers (deletion mutants) and the 2,150 rhizosphere isolates.
From: Competition for iron drives phytopathogen control by natural rhizosphere microbiomes
a, CAS values of the two defined wild-type laboratory strains (producer) and the corresponding siderophore-deficient mutants (non-producer) under iron-limited (yellow) and iron-rich (purple) conditions. We used the background CAS values of the siderophore-deficient mutants as a cut-off value to distinguish background CAS activity from siderophore production. Data represent the mean±s.d. of the siderophore production, n=4 independent biological replicates (shown as black dots over the bars). b, Mean siderophore production of the 2150 rhizosphere isolates is significantly higher under iron-limited compared to iron-rich conditions. Box plots encompass the 25–75th percentiles, the whiskers extend to the minimum and maximum points and the midline indicates the median (n=2150 biologically independent rhizobacterial isolates. P values were determined based on analysis of variance (ANOVA) followed by paired two-sided Student’s t test. P<2.2×10-16 (*P < 0.05, **P < 0.01, ***P < 0.001)). c, Iron limitation induces siderophore production in up to 99% of all siderophore producers (values fall below the solid black line). Data points that fall on the solid black line, ie, the diagonal of the square, denotes that equal amount of siderophores were produced under iron-limited and iron-rich conditions. The black dashed lines represent the background CAS values of the two siderophore non-producers under iron-limited and iron-rich conditions, respectively.
