Figure 9.

HapX Is Required for Efficient Iron Competition of F. oxysporum with Fluorescent Pseudomonads.

Growth of the indicated F. oxysporum strains was determined on solid MM in the presence of the rhizosphere-colonizing bacterial strains P. putida KT2440 (wild-type [wt] or pvd⁻, strain lacking the siderophore Pvd) or P. fluorescens SBW25 (wild-type, pvd⁻, or pvd⁻ ocg⁻ lacking the siderophores Pvd and Ocg). F. oxysporum microconidia were evenly spread on top of Glc casamino acids medium with or without iron. Bacterial strains were point-inoculated on the same day, and cultures were incubated for 4 d at 28°C. Mycelial growth is visible as a gray background, whereas growth inhibition appears as a dark halo surrounding the bacterial colony.

Bars = 5 mm.