Figure 5. Al stress up‐regulated the expression of IPTs in the root‐apex TZ that is important for the Al‐induced root growth inhibition.

1. The expression of the IPT1 _pro :GFP, IPT3 _pro :IPT3‐GFP, IPT5 _pro :GFP, and IPT7 _pro :GFP transgenes in the epidermis of root‐apex TZ after a 2‐h exposure to 25 μM AlCl₃. Cell boundaries appear red following propidium iodide staining. The root‐apex TZ is marked by yellow arrowheads. Scale bar: 100 μm.
2. Relative primary root growth of the WT and IPT mutants as affected by a 7‐day exposure to 6 μM AlCl₃. The data are shown as mean ± SD (n = 3). * and **: means differ significantly within the WT and mutants at, respectively, P < 0.05 and P < 0.01 (t‐test). At least 60 seedlings were analyzed from three biological repeats (around 20 seedlings for each repeat).