念珠藻葛仙米生理生化特性对不同低温胁迫的响应  

Response of Nostoc sphaeroides(Cyanobacterium) to Low Culture Temperatures

作　　者：苏彦平[1] 李敦海[1] 王坎[1] 刘永定[1] 

机构地区：[1]中国科学院水生生物研究所

出　　处：《武汉植物学研究》2008年第3期310-314,共5页Journal of Wuhan Botanical Research

基　　金：中国科学院前沿性创新课题(KSCX2-SW-332);国家973项目(2002CB412300)联合资助

摘　　要：研究了不同培养温度下对念珠藻葛仙米的生长和相关生理生化特性的变化。结果表明，低温抑制葛仙米的生长，在2℃-5℃低温下其生长甚至完全停止；在10℃低温胁迫下，其生长延滞期变长，其后仍能保持正常生长。低温胁迫下，葛仙米光合系统Ⅱ（PSⅡ）的光合效率（Fv／Fm）的变化趋势与生长曲线相似；细胞电解质渗透率在低温胁迫初期尚能保持比较低的水平，但随着时问延长而升高；可溶性糖和还原性糖含量的变化则随胁迫加剧有不同程度升高。可溶性蛋白含量则在低温下保持比较低的水平。这些结果表明，低温对葛仙米的生长和光合作用具有抑制作用，但葛仙米也表现出了一定的抵抗低温胁迫的能力，并通过调节细胞膜的渗透性、重新合成低温适应调节物质（如总糖和可溶性糖等）来减少低温伤害，从而适应低温胁迫。The effects of low temperatures on some physiological and biochemical characteristics of Nostoc sphaeroides kǔtz, were studied. Results showed that the growth of N. sphaeroides was inhibited by low tem-peratures, most severely, it was nearly ceased at 2℃ and 5℃, while, at 10℃, and normal growth was attained after a prolonged lag phase. Change of photosynthetic activity （represented by Fv/Fm） in N. spha-eroides under low temperatures was similar to that of the growth. The permeability of cell membrane could maintain a low level at initial stage, and then increased with prolonged low temperature treatment. With lower temperature stress, the contents of total sugar and reducing sugar increased to variant extents. Content of soluble protein in N. sphaeroides kept at a low level when it was subjected to chilling stress. All the results indicate that the growth and photosynthetic activity of N. sphaeroides could be inhibited by low tem-perature, however, the algal cells can also show abilities of chill-resisting, adapting to low temperatures by membrane permeability regulating and chilling-adjusting substances （such as total sugars and soluble sugars） synthesizing.

关 键 词：葛仙米 低温胁迫 电解质渗透率 可溶性糖 还原性糖 可溶性蛋白 

分 类 号：Q945.78[生物学—植物学]