HapX-Mediated Adaption to Iron Starvation Is Crucial for Virulence of Aspergillus fumigatus
Figure 2
During iron depleted but not iron-replete conditions, HapX-deficiency impairs growth in liquid and solid media, colony formation from single conidia, conidiation, resistance to zinc and tetracycline, and causes reddish pigmentation.
(A) Growth on solid media with and without tetracycline: conidia were point-inoculated on plates reflecting harsh iron starvation (−Fe +BPS), iron starvation (−Fe) and iron-replete conditions (+Fe). Radial growth was recorded after 48h of growth at 37°C and normalized to that of wt grown under the same condition. (B) Colony formation from single conidia: approximately 100 conidia were plated and photographs were taken after growth for 48h at 37°C. (C) Conidiation: conidia production by 1 cm2 of mycelia after growth for 120h of at 37°C was recorded and normalized to that of wt under the same condition. (D) Hyphal pigmentation: photographs of liquid cultures were taken after 24h of growth at 37°C. (E) Growth in liquid media with and without limitations or zinc excess: biomass production of 108 conidia inoculated in 100 ml media was scored after 24 h of growth at 37°C and normalized to that of wt in +Fe. For limitation of carbon (−C), nitrogen (−N), zinc (−Zn) and copper (−Cu), the growth medium contained 0.1% glucose, 2 mM glutamine, 1 mM ZnSO4 and no added copper, respectively, which decreased the biomass production of the wt to about the same extent as iron limitation. High zinc-medium (hZn) contained 0.5mM ZnSO4. The data in (A), (C), and (E) represent the means ± standard deviations from three independent experiments.