Aluminium toxicity, Al tolerance and oxidative stress in an Al-sensitive wheat genotype and in Al-tolerant lines developed by in vitro microspore selection

The formation of reactive oxygen species induced by aluminium stress was investigated in an Al-sensitive wheat (Triticum aestivum L.) genotype and in Al-tolerant lines developed by in vitro microspore selection. The roots of M-tolerant plants were found to exhibit more intensive root growth, while accumulating less Al3+ and reactive oxygen species than Al-sensitive plants under Al stress condition. Aluminium accumulation was found chiefly in the root apex, while the formation of superoxides and peroxides was detected mainly in the elongation zone. Among the superoxide dismutase, ascorbate peroxidase (APX), catalase (Cat) and glutathione-S-transferase (GST) enzymes induced by Al stress, catalase and GST may play an important role in the detoxification of reactive oxygen species in Al-tolerant plants, since they were found to have higher activity than in the M-sensitive plant. (C) 2003 Elsevier Ireland Ltd. All rights reserved.