Figure 1.

Loss of hapX Impairs Growth of F. oxysporum under Iron-Limiting Conditions but Not Iron Uptake.

(A) Growth of the indicated fungal strains on solid media differing in availability of iron. Cultures were grown for 3 d at 28°C. wt, wild type.

(B) Relative mycelial growth of the indicated strains on MM with or without Fe was estimated by measuring the area corresponding to fungal colonies on the inverted contrast images in (A), and normalized to the growth of the wild type strain on MM+Fe.

(C) Relative dry biomass of the indicated strains grown in liquid MM with or without Fe for 5 d at 28°C. Bars represent se from three independent experiments with three technical replicates each. Values with the same letter are not significantly different according to Mann-Whitney test (P = 0.05).

(D) The indicated strains were grown in iron-depleted MM for 24 h and transferred for 1 h to iron-depleted MM (−Fe) or iron-replete MM (+Fe). Intracellular iron concentration was determined colorimetrically and expressed relative to the wild-type strain under iron-depleted conditions. Bars represent se from three independent experiments with three technical replicates each. Values with the same letter are not significantly different according to Mann-Whitney test (P = 0.05).

Bars in (A) = 5 mm.

[See online article for color version of this figure.]