FIG. 4.

Activity of A. thaliana ZIP1 in E. coli. Overnight cultures of E. coli strain GR536 (ΔfecABCDE::kan ΔzupT::cat ΔmntH ΔentC ΔfeoABC) grown in Luria-Bertani broth were diluted 1:500 into Tris-buffered mineral salt medium and grown overnight. Cells were diluted 1:500 into fresh medium, and after 2 h of growth at 37°C, cells were diluted 1:500 into fresh medium with iron or different concentrations of EDTA. Cell growth was monitored as the optical density at 600 nm after 16 h of incubation at 37°C with shaking, and the dry weight was determined. E. coli strain GR536 (ΔfecABCDE::kan ΔzupT::cat ΔmntH ΔentC ΔfeoABC) pACYC184 (white), pZUPT-low (black), and pZIP1 (grey) are shown. Experiments were performed in triplicate, and the averages with standard deviations were calculated.