Fig. 5.

Effect of polyethylene glycol (PEG) treatment on relative (no PEG = 100) Al, La and Sr accumulation of 10 mm root tips of Al-sensitive common bean genotype VAX-1. Plants were pre-treated with PEG (150 g L⁻¹) for 8 h in a simplified solution (pH 4·5) containing 5 mm CaCl₂, 1 mm KCl and 8 mm H₃BO₃. Then the plants were supplied with 25 mm AlCl₃, 5 mm LaCl₃ or 2·5 mm SrCl₂ in the absence or presence of PEG (150 g L⁻¹) in the same nutrient solution for 1 h. The hydrated ionic diameters are indicated under the ions. Bars represent means ± s.d. (n = 4). (Z. Yang et al., Leibniz University Hannover, Germany, unpubl. res.)