外源糖对爪哇伪枝藻低温胁迫耐受性的影响  

Influences of Exterior Saccharides on the Endurance of Low Temperature Stress of Scytonema javanicum

作　　者：饶本强[1,2] 黄斌[1] 陈坤[1] 刘永定[2] 

机构地区：[1]信阳师范学院生命科学学院,河南信阳464000 [2]中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,湖北武汉430072

出　　处：《信阳师范学院学报（自然科学版）》2010年第3期384-388,共5页Journal of Xinyang Normal University(Natural Science Edition)

基　　金：淡水生态与生物技术国家重点实验室资助项目(2008FBZ21);河南省教育厅自然科学研究计划项目(2010B180026);信阳师范学院青年骨干教师资助计划项目;信阳师范学院高层次人才科研启动基金项目

摘　　要：以一种从荒漠结皮中分离的典型蓝藻——爪哇伪枝藻为材料,在实验室条件下设置2、10和25℃(对照)进行低温处理,并向低温处理的藻培养物中添加0.2 g/L蔗糖和0.2 g/L葡萄糖,测定低温胁迫和外源糖对伪枝藻生物量、光合活性、膜脂过氧化产物丙二醛含量、细胞可溶性蛋白质含量和胞外多糖分泌的影响.研究结果显示,与对照处理相比,低温胁迫导致伪枝藻生物量和光合活性的显著降低,细胞内可溶性蛋白呈现明显增高.同时低温处理导致伪枝藻膜脂的过氧化伤害,即丙二醛含量的大量增加.添加外源糖处理时发现,蔗糖和葡萄糖有利于提高伪枝藻对低温胁迫的耐受性.研究还发现,经过48 h、10℃低温适应处理的伪枝藻骤然降至2℃时,出现胞外多糖的大量分泌.研究结果表明糖类物质可能对于提高伪枝藻的低温胁迫耐受性具有重要调节作用,为更好地理解荒漠结皮蓝藻对极端环境的耐受机制提供了有意义的参考.A typical desert canobacteria,Scytonema javanicum,isolated from desert algal crusts,was selected for research material.In the experiments,2,10 and 25 ℃（as control） were selected for temperature treatments,and simultaneously treatment were conducted by adding exterior saccharides such as sucrose and glucose into the algae cultures under the corresponding low temperature treatments.Final concentrations of the two sugars in culture media were 0.2 g/L,respectively.The biomass（expressed as chlorophyll a）,PSⅡ activity（Fv/Fm）,MDA contents and intracellular production of water-soluble proteins as well as the excretion of exopolysaccharides（EPS） were investigated within S.javanicum under low temperature stress.The results showed that low temperature resulted in an obvious decrease in biomass and PSⅡ activity of the algal cells when compared to the control cells.It also indicated in the study that intracellular production of water-soluble proteins were comparatively greater in the treated cells than the control cells,and simultaneously low temperature stress had a significantly deleterious effect on membrane lipid superoxide as assessed by measurement of MDA content.In addition,we found that S.javanicum had an apparent increase in secretion of EPS when it abruptly dropped to 2 ℃ after 48 h low temperature adaptation in 10 ℃.Research results may strongly suggest that saccharides are crucial for the stress tolerance of S.javanicum during low temperature,and provide us a significative finding for better understanding stress tolerance of desert cyanobacteria subjected to extreme environments.

关 键 词：爪哇伪枝藻 低温胁迫 外源糖 胞外多糖 低温适应 

分 类 号：Q949.25[生物学—植物学]