Figure 4.

Zn²⁺ and Cd²⁺ concentrations of transgenic and WT tobacco in shoots and roots. (a) Zn contents in shoots. (b) Zn contents in roots. (c) Cd contents in shoots. (d) Cd contents in roots. WT: Wild-type tobacco. N13, N14, N24: Three homozygous transgenic tobacco lines (T₂). The 4−week−old WT and transgenic plants were treated under Zn²⁺ (0, 300, or 900 mg/kg) or Cd²⁺ (0, 100, or 200 mg/kg) for 3 weeks, respectively. Asterisks indicate the significant difference between transgenic lines and WT (*, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001).