角果木根系盐胁迫的防御机理

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

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。

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.