Induction of O2•− generation in Arabidopsis thaliana cell suspension culture by AlCl3. (A,B) Typical traces of AlCl3-induced immediate O2•− generation and effect of inhibitor and scavengers, namely 1 mM diphenyleneiodonium chloride (DPI), 0.2 mM Fe(III)-EDTA and 5,000 units/ml SOD. (C,D) Typical traces of AlCl3-induced increase in CLA-chemiluminescence reflecting the prolonged production of O2•− in Arabidopsis thaliana cells. Error bars reflect the mean and SD, (n = 3).