脱水和复水金发藓酶清除ROS系统响应机制

以生存于变水环境中的金发藓为材料，通过快速脱水和复水的方式，探究金发藓在脱水胁迫时对于活性氧的响应机制，并进一步探究苔藓植物脱水耐性特性.结果显示：（1）随着脱水时间的增长，金发藓内积累大量的活性氧物质，脱水至120 min时·O^-₂、H₂O₂和OH^-等都达到最高水平；（2）抗氧化剂SOD，CAT，APX，ASA，GSH等在脱水复水过程中均上升，复水后下降，但是GSH和ASA在120 min复水后期仍未能恢复到对照水平;（3）金发藓在应对氧化胁迫过程中，通过启动ASA-GSH代谢循环途径以应对氧化胁迫.研究表明，金发藓对于脱水环境导致的氧化胁迫具有很强的应对能力，而且在复水后在极短的时间内能恢复生命活性，金发藓有效的抗氧化代谢机制使金发藓能长期生存于多变水环境中.

Systematic Response Mechanism of Enzyme Removing ROS in Polytrichum Commune During Dehydration and Rehydration

The response mechanism of polytrichum commune in poikilohydrous habitat to reactive oxygen under different dehydration and rehydration stress is explored and its desiccation endurance is investigated.The results show that:(1)the reactive oxygen species accumulate in polytrichum commune with the increase in dehydration time, and the reactive oxygen species(·O^-₂、H₂O₂ and OH^-) increase to maximum when dehydration lasts 120 mins；(2) the antioxidants SOD、CAT、APX、ASA and GSH increase during dehydration and decrease after rehydration,but GSH and ASA do not recover to the normal level after 120 mins of rehydration;(3)polytrichum commune responds to oxidative stress through ASA-GSH cycle system.It can be concluded that polytrichum commune has good response to oxidative stress caused by dehydration,and its life activity recovers in a very short period of rehydration; this response mechanism enables polytrichum commune survive in poikilohydrous habitat.