Fig. 5.

Effect of A-9-C and PI on the citrate efflux (A) and content (B) after 6 h pulse treatment with 50 µm AlCl₃. Seedlings were exposed to 0.5 mm CaCl₂ solution (pH 4.5) containing 50 µm AlCl₃ for 6 h and then transferred to 0.5 mm CaCl₂ solution (pH 4.5) containing 20 µm A-9-C, 20 µm PI or both. Root exudates were collected every 3 h for determination of citrate efflux, and apical 5 mm root apices were excised for endogenous citrate content analysis. Error bars represent ± s.d. (n = 3).