Figure 4.

Effect of iron supplementation on cadmium and nickel tolerance. Serial dilution assays comparing the iron uptake impaired deletion mutant strain fet3Δ and wild-type (WT) cells grown in the presence of cadmium (40 μmol/l) or nickel (2.5 mmol/l) and supplemented with the indicated concentrations of FeCl₃. A no-metal control is shown at the top; similar results (not shown) were obtained with a strain deleted in FTR1, the other component of the Fet3/Ftr1 high-affinity iron uptake system. YPD, yeast extract-peptone-dextrose.