Figure 1.

Time course of malate efflux from root apexes of Al-resistant wheat (cv Atlas) after exposure to 200 μm AlCl₃. Excised root apexes (2 mm in length from root apices) were exposed to 200 μm CaCl₂ (○; Ca solution) or the Ca solution containing 200 μm Al (pH 4.2) (●; Ca+Al solution) passing through at a flow rate of 0.5 mL min⁻¹. Root apexes were exposed to the Ca+Al solution for 1 min (♦) followed by three rinses with the Ca solution, and subsequent exposure to the Ca solution at a flow rate of 0.5 mL min⁻¹ from 5 min after addition of the Ca+Al solution. Eluents passed through root apexes were collected every 1 min and assayed for determination of malate concentration. Treatments replicated three times gave similar results. Data from a representative experiment are shown.