低温胁迫对节旋藻质膜的伤害

Damage of Plasma Membranes of Arthrospira under Low Temperature Stress

低温胁迫下,对鄂尔多斯高原碱湖的钝顶节旋藻(A1)、非洲Chad湖的钝顶节旋藻(A2)和墨西哥Texcoco湖的极大节旋藻(A3)的质膜伤害进行比较研究,以了解来自中纬度与低纬度不同节旋藻对低温的反应,探讨其对低温的适应性及与原产地的关系.结果表明,无论直接低温处理还是经低温锻炼后再低温处理,随温度的降低3个样品细胞外渗液中可溶性蛋白和游离氨基酸的含量均增加,且胁迫的温度越低、时间越长,细胞外渗液中两种物质的含量也越高.经低温锻炼可减弱低温胁迫对节旋藻质膜的伤害,相比之下,对A1作用更明显.在相同的处理条件下,外渗液中蛋白质和游离氨基酸的含量均是A1<A2<A3,质膜伤害率A1比A2和A3低,特别是在处理温度低、时间长时表现得更为明显.说明A1对低温有较强的适应性.

To explore the responses to low temperature of Arthrospira from middle and low latitude areas,and to analyse the relationship between their adaptability to low temperature and their origin area,the damage of plasma membranes under low temperature was studied in A.platensis（A1） from alkaline lakes in Erdos Plateau,A.platensis（A2） from Chad Lake and A.maxima（A3） from Texcoco Lake.The results showed that contents of soluble proteins and free amino acid in the liquid of exosmosis increased with decreasing temperature in three Arthrospira,which treated with direct low temperatue or low temperature hardening.The contents of that were higher in a lower temperature and longer time.Low temperature hardening can weaken the damage of low temperature to plasma membranes in Arthrospira,especially in A1.In the same conditions,the contents of the soluble proteins and free amino acid in exosmosis liquid were A1A2A3,these results were obvious especially at lower temperature and under longer time treatment.Therefore,A1 has better adaptability to lower temperature.