铁、镁、锌营养胁迫对植物体内活性氧代谢影响机制

活性氧是植物体内常见的一类自由基,对植物有很强的伤害。本文总结了铁、镁、锌元素胁迫影响植物体内活性氧代谢机制。铁对于催化植物体内的Haber-Weiss反应产生活性氧具有重要作用。镁诱导植物体内活性氧代谢失调与光氧化有密切关系。缺锌条件下,植物体内活性氧含量升高,其机制是多方面的:NADPH氧化酶氧化能力提高,O2产生增多;体内铁浓度升高,增强了铁诱导的活性氧的产生;光氧化伤害加重;清除系统活性降低。

Possible effects of iron, magnesium and zinc on the metabolism of reactive oxygen species in plants

The reactive oxygen species(ROS) are common free radicals in higher plants.Excess ROS are produced in plants when subjected to various environmental stresses and result in damages to plants.The possible effects of some nutrient elements such as iron,magnesium and zinc on the metabolism of ROS in plants were reviewed.The role of iron in generating ROS is mainly through Haber-Weiss reaction.The high levels of ROS caused by Mg deficiency induce the higher activities of detoxification enzymes of ROS.The main mechanism underlying is that plant photooxidation is enhanced by Mg deficiency since photosynthetic carbon fixation is inhibited or slows down under Mg deficiency.Increasing evidences show that oxidative damages to cell resulting from the attack by ROS are the basis of disturbances in plant growth caused by zinc deficiency.Under zinc deficiency,membrane-bound NADPH oxidase producing ROS increases,while the activities of some detoxification enzymes of ROS reduce.The higher iron concentration is often observed in Zn deficient plants.Plant photooxidation is also enhanced by Zn deficiency.