Effects of aluminum on physiological metabolism and antioxidant system of wheat (Triticum aestivum L.).

The Al-tolerant cultivar TAM202 and the Al-sensitive cultivar TAM 105 of winter wheat (Triticum aestivum L.) were exposed to 0, 50, 75, 100 or 150 microM of Al. The absorption of Al by wheat, the growth of root, several key enzymes concerned with C, N and P metabolism, as well as key constituents of antioxidant system, were investigated. The results showed that TAM105 absorbed more Al than TAM202 and its root growth (presented by the length) was inhibited more severely. The root growth was most closely related to mononuclear Al (Ala) activity. The metabolic enzymes (presented by glucose-6-phosphate dehydrogenase, nitrate reductase and acid phosphatase) in TAM202 were Al-tolerant. Presented by superoxide dimutase (SOD) and the content of reduced glutathione (GSH) and malondialdehyde (MDA), antioxidant system in TAM202 indicated lower oxidative stress and greater ability to protect the cultivar.