模拟干旱胁迫对发状念珠藻抗氧化酶系统和渗透调节物质的影响  

Effect of Simulated Drought Stress on Antioxidant System and Osmotic Regulation in Cells of Nostoc flagelliforme

作　　者：周娟[1] 范红丽[1] 白丽甜 郑蕊[1] 岳思君[1] 

机构地区：[1]宁夏大学生命科学学院,宁夏银川750021

出　　处：《新疆农业科学》2016年第5期915-920,共6页Xinjiang Agricultural Sciences

基　　金：国家自然科学基金项目(31360025;31560418)~~

摘　　要：【目的】探讨模拟干旱胁迫对发状念珠藻抗氧化酶系统和渗透调节物质的影响。【方法】以发状念珠藻细胞为实验材料,用2%、4%、6%、8%、10%浓度的PEG-6000模拟干旱胁迫,测定发状念珠藻氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性及胞外多糖(EPS)和脯氨酸(Pro)含量的变化。【结果】与对照处理相比,随着干旱胁迫程度的增加,发状念珠藻细胞的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性均呈现先上升后下降的趋势,细胞胞外多糖(EPS)和脯氨酸(Pro)含量呈增加趋势,但在高浓度的胁迫下,脯氨酸的含量呈现下降趋势。【结论】发状念珠藻在中度干旱胁迫下能够激活自身的抗氧化酶类以提高藻细胞的抗氧化能力,从而能消除或减轻活性氧毒害,而在重度干旱胁迫下,酶活降低,标志活性氧清除机制受到破坏,抗氧化能力降低。在干旱胁迫下,作为渗透调节物质的胞外多糖和脯氨酸表现出缓解干旱胁迫的效果,累积的脯氨酸和胞外多糖能够维持细胞内渗透平衡,保证细胞内正常的物质代谢,从而提高发状念珠藻对干旱胁迫的适应性。【Objective】The objective of this study is to explore the effect of different drought stress on antioxidant system activety and osmotic regulation substance contents of Nostoc flagelliforme. 【Method】The Nostoc flagelliforme cells were used as experimental materials and PEG- 6000 with different concertrations（ 0,2%,4%,6%,8%,10%） were used to simulate the water stress. And the change of superoxide dismutase（ SOD）,peroxidase（ POD）,catalase（ CAT） activrty and the content of extracellular polysaccharide（ EPS）,proline（ Pro） of Nostoc flagelliforme were determined. 【Result】The results showed that the contents of Nostoc flagelliforme SOD,POD,CAT activity first increased,and then declined. The content of proline（ Pro） and extracellular polysaccharide（ EPS） always increased under the low drought treatment,but the proline content showed a trend of decline under the servere drought reatment 【Conclusion】The research illustrated under medium drought treatment the antioxidant enzyme of nostoc flagelliforme adjusted itself to increase its antioxidant capability. This can avoid active oxygen species injury. But under severe drought treatment,the capability has already fallen down obviously because some active oxygen scavenging was destroyed. Under drought stress treatment,extracellular polysaccharide and proline of osmotic regulation substances showed the effect of alleviating drought stress,and the accumulation of proline and extracellular polysaccharide could maintain intracellular osmotic balance and ensure normal metabolism in cells,which is likely to improve the adaptability of Nostoc flagelliforme under drought stress.

关 键 词：发状念珠藻 干旱胁迫 抗氧化酶系统 渗透调节物质 

分 类 号：S188[农业科学—农业基础科学]