盐胁迫对红海榄幼苗根茎叶膜保护系统的影响

The effect of salt stress on membrane protection system for roots, stems and leaves of Rhizophora stylosa seedlings

红海榄（Rhizophora stylosa）属于乔木红树植物,它对不同盐度的生理反应存在着差异。本文通过对拒盐红树植物红海榄Rs在盐胁迫下各种生理反应的研究,分析了各种生理现象与盐度之间的关系,这对红树植物耐盐机理的研究打下了基础,并为中国南海岸耐盐红树树种的选育提供科学依据,也有助于从多学科研究的角度评估盐胁迫的生态重要性。通过对Rs用不同的盐度的水3个月的处理,发现Rs根、茎、叶中蛋白质质量分数随盐度的变化趋势与可溶性总糖质量分数与盐度的变化趋势相反。当盐度高于40时,Rs茎、叶的膜脂质过氧化破坏显著加强,植物体内超氧化物歧化酶（SOD）活性也明显增加,两者具有很好的相关性（R2=0.893）。随着盐度的升高,Rs各器官过氧化物酶（POD）和过氧化氢酶（CAT）活性都增强。根据实验结果,Rs能够在高盐度（50）下存活3个月。在盐度为20-30时,Rs在生理生态上表现对盐环境的适应性。当盐度高于40时,Rs的生理表现较为敏感,膜脂质氧化破坏严重。

Rhizophora stylosa （Rs） are arboreal mangrove plants. The responses of Rs to different salinity are relatively dissimilar. The physiological response of salt-rejecting mangrove plants Rs to salt stress were studied and the relationship between physiological response and salinity was analyzed. This lays a foundation for the study of salt tolerance mechanism, and provides a scientific basis for the selection and cultivation of salt tolerant mangrove species along the South China coast. In addition, it helps to evaluate the ecological importance of salt stress from a multidisciplinary point of view. In this paper, the mangrove specie Rs was treated with different salinity for 3 months. It was found that the tendency of protein content in roots, stems and leaves in Rs with salt concentration were reverse exactly with the tendency of soluble sugar content＇s. When salinity is higher than 40, the effect of membrane peroxidation enhanced remarkably, the activity of superoxide dismutase （SOD） enhanced either and there is correlativity in them （R2=0.893）. The activity of peroxidase （POD） and activity ofcatalase （CAT） in various organs of Rs enhanced with salt concentration. According to the results of experimentations, it can be known that Rs can survive for 3 months in 50 salinity. Rs exhibits the physiological adaptabilities between 20 and 30 salinity. Rs is sensitive in physiology when salinity is higher than 40 and the effect of membrane peroxidation strengthened.