Figure 7.

Effect of exogenous IAA supply (0.1 μm in 1.2% [w/v] agarose blocks containing nutrient solution) for 1 h to different apical root zones (A, MZ 0–1 mm; B, EZ 2.5–3.5 mm) on Al-induced inhibition of elongation of primary roots of the maize cv ATP-Y (Al-resistant) and cv Lixis (Al-sensitive). Ninety micromolar monomeric Al (gray bars) or 10 μm TIBA (black bars) in 0.6% (w/v) agarose gel was applied to the 1-to 2-mm root zone (DTZ). White bars, Control (−Al). Values are means of five independent replicates ± sd. The results shown are representative of three independent experiments. Different letters indicate significant differences at P < 0.05 (Tukey's test).