Figure 7.

Overexpression of AtNramp3 confers Cd²⁺ hypersensitivity in Arabidopsis. (A) Northern blot analysis of an overexpressing line. Conditions are as described in Fig. 5. (B) Root growth hypersensitivity to Cd²⁺. Arabidopsis seedlings were grown vertically for 10 days on plates containing minimal medium supplemented (Right) or not (Left) with 1 μM Cd²⁺. (C) Root length of Arabidopsis seedlings grown vertically for 10 days on plates containing minimal medium supplemented with 0, 1, or 10 μM Cd²⁺. The graph represents the results of one representative experiment of four with one of the two lines analyzed in detail. Values are mean of measurements on 12–16 roots, and error bars represent SE. (D) Iron over-accumulation in ³⁵S-AtNramp3 plants on Cd²⁺ treatment. Arabidopsis seedlings were grown for 10 days in liquid minimal medium supplemented or not with 1 μM Cd²⁺. The Fe content was quantified by inductively coupled plasma optical emission spectroscopy. The mean ± SE of three independent experiments is represented. Control (open bars): homozygous, single insertion line transformed with empty pMON530. ³⁵S-AtNramp3 (filled bars): homozygous, single insertion line transformed with pMON530 containing AtNramp3 cDNA driven by the ³⁵S CaMV promoter.