铝胁迫下不同耐铝小麦品种活性氧代谢差异及与小麦耐铝性的关系

逆境条件下植物体内产生并累积活性氧从而破坏植物组织结构与功能,同时植物也可以通过改变活性氧代谢相关酶活性清除活性氧而减轻活性氧伤害以适应环境胁迫。为研究铝胁迫下不同耐铝小麦品种(Triticum aestivum L.)在活性氧代谢上的差异及与小麦耐铝性的关系,本试验选用小麦品种ET8(耐铝型)、ES8(铝敏感型)为试验材料研究了不同耐铝小麦品种活性氧代谢变化上的差异。结果表明,50μmol·L-1铝处理24h,ET8和ES8活性氧含量显著升高,O2·ˉ产生速率增幅分别为10.5%和20.4%,H2O2含量增幅分别为3.3%和7.6%。ET8和ES8超氧化物歧化酶(SOD)活性增幅分别为11.9%和41.6%,过氧化物酶(POD)活性增幅为51.8%和77.8%,抗坏血酸过氧化物酶(APX)活性增幅为54.4%和29.1%,过氧化氢酶(CAT)活性增幅为32.9%和38.4%,谷胱甘肽还原酶(GR)活性增幅为83.1%和85.5%。虽然抗氧化酶活性增加后会清除一部分活性氧,但活性氧的累积仍然造成了膜脂的过氧化,ET8和ES8丙二醛(MDA)含量分别增加18.2%和50.0%,质膜透性也随着MDA含量的升高而增加,增幅分别为1.25倍和1.36倍。综上所述,不同耐铝品种间活性氧代谢的差异是小麦品种耐铝性差异显著的原因之一。

Active oxygen metabolism differences and Al tolerance of different Al-tolerant wheat under aluminum stress

The production and accumulation of reactive oxygen species (ROS) in plant can damage the structure and function of tissues under stress conditions. Meanwhile, plant can adapt to stress conditions by changing the activities of active oxygen metabo-lism enzymes to clear and alleviate the damage of ROS. In this study, Al-tolerant wheat (Triticum aestivum L.) ET8 and Al-sensitive wheat ES8 were supplied to investigate the relationship between active oxygen metabolism and Al tolerance in wheat. The results showed that the contents of active oxygen increased significantly in Al-tolerant wheat ET8 and Al-sensitive wheat ES8 with the treatments of 50 μmol·L~(-1) Al for 24 h. The O_2~(·-) in ET8 and ES8 increased by 10.5% and 20.4% respectively, and the H_2O_2 increased by 3.3% and 7.6%. The super oxide dismutase (SOD) in ET8 and ES8 increased by 11.9% and 41.6% respectively, the peroxidase (POD) increased by 51.8% and 77.8% respectively, the aacorbate peroxidase (APX) increased by 54.4% and 29.1% respectively, the catalase (CAT) increased by 32.9% and 38.4% respectively, and the glutathione reductase (GR) increased by 83.1% and 85.5% re-spectively. Although parts of the ROS could be cleared by active oxygen metabolism enzymes, the accumulation of ROS still in-duced the peroxidation of membrane lipids. The malondialdehyde (MDA) in ET8 and ES8 increased by 18.2% and 50.0% respec-tively, and the membrane permeability increased by 1.25 and 1.36 times respectively. In conclusion, the significant difference in active oxygen metabolism is one of main reasons that cause the Al-resistant difference among different Al-tolerant wheat species.