Fig. 1.

Citrate release and VuMATE1 expression time series. (A) Induction of citrate secretion from root apices of rice bean by Al treatment. Excised root apices (10mm in length) were placed in 0.5mM CaCl₂ solution containing 0 or 25 μM Al. Data are means ± standard deviation (SD) of three independent experiments (n=3 for each experiment). (B) Time course of VuMATE1 expression in the roots of rice bean in response to Al treatment. Expression levels were normalized to that of the 18S rRNA gene and then to the expression of VuMATE1 in root apices at 3h of Al treatment, which was arbitrarily fixed at 1. VuMATE1 expression in root apices treated with 0.5mM CaCl₂ solution for 12h was included. Results are shown as mean expression ±SD of three independent experiments. n.d. indicates that no signal was detected. The inset shows semi-quantitative RT-PCR of VuMATE1 expression.