Abstract: Variation of aluminum in form and distribution is recognized to be associated with environmental pH.Effect of activated aluminum（Al_a,Al_b） on contents of reductive glutathione（GSH）and malondialdehyde（MDA）in wheat was investigated by changing the pH of aluminum solutions.The experiment was designed to have three total Al concentration treatments,0 μmol·L^-1（CK）,25 μmol·L^-1（T1） and 75 μmol·L^-1（T2）,and four pH levels,4.0,4.5,5.0 and 5.5,for each treatment.Results show that low concentrations of Al_a and Al_b significantly affected contents of GSH in the roots,stems and leaves of wheat,showing a process of inducement,increase and consumption of GSH in the roots and leaves of wheat.The GSH contents in leaves reached minimum of this experiment at pH 4.5 in treatment T2(75 μmol·L^-1 Al),while MDA accumulated in the leaves,suggesting that Al reached its maximum toxicity at pH 4.5 by 75 μmol·L^-1 in the study.

Key words: activated aluminum, wheat, glutathione, malondialdehyde