角果木根系盐胁迫的防御机理

以强耐盐性红树植物角果木为研究对象,采用不同浓度的NaCl溶液(0,150,300,450mmol·L-1)对角果木幼苗进行盐胁迫处理,测定角果木根部的SOD,POD,ASA,MDA等生理指标。结果表明:角果木在适应盐环境的过程中有新的蛋白产生,在盐胁迫早期(≤9h)MDA含量急剧上升,这种信号诱导了抗氧化防御系统的启动,使角果木根部抗氧化酶类及抗氧化物质均有所增加,说明角果木盐胁迫下通过启动抗氧化酶类、抗氧化物质以清除活性氧对根部的损伤,而后开始适应外界盐环境。

Preliminary Study on the Salt Stress Defense Mechanisms of Ceriops tagal Root

Mangroves are woody plants that grow along tropical and subtropical coasts and form clumpy stands in intertidal zones. The anatomical and physiological features associated with their salt-tolerant lifestyles have not been well characterized,little is known about the impact of defensive enzymes on their adaptation to these saline environments. In this study,the enzyme activity of superoxide dismutase （ SOD） ,peroxidase （ POD） ,ascorbic acid（ ASA） and Malondialdehyde （ MDA） in the C. tagal roots treated by four concentrations （ 0,150,300,450 mmol·L^–1 ） of NaCl were studied in a greenhouse of Hainan University,Haikou,China. The results showed that the activity of MDA had a sharp increase at early stressed time,and this signal induces the appearance of antioxidative defensive system,including a certain increase of SOD,POD,ASA. which indicated that cell plasma membrane of C. tagal roots had rather strong resistance to the injury of salt ion. These results established a theoretical foundation for salt tolerance mechanism of C. tagal.