盐度对盐生杜氏藻叶绿体超微结构的影响

研究不同盐度对盐生杜氏藻（ Ｄｕｎａｌｉｅｌｌａｓａｌｉｎａ（ Ｄｕｎａｌ．） Ｔｅｏｄ ．） 叶绿体超微结构的影响．结果显示，在ＮａＣｌ 浓度为２ ．７ ｍｏｌ／Ｌ 的培养液中，其叶绿体为典型的杯状结构．在ＮａＣｌ 浓度从２ ．７ ｍｏｌ／Ｌ 增加到４ ．３ ｍｏｌ／Ｌ时，其杯状叶绿体逐渐离解为多个相互连结或分离的部分；叶绿体内的类囊体片层系统解体并出现大量的嗜锇质体小球；在分离的叶绿体间隙中形成多个线粒体．在培养液的ＮａＣｌ 浓度逐步从４ ．３ ｍｏｌ／Ｌ 降低到２ ．７ ｍｏｌ／Ｌ后，盐藻的叶绿体又逐步恢复为典型的杯状结构．由此可知，不同盐度下盐藻叶绿体的结构变化是一个可逆的过程，这种可逆变化是盐藻得以在高盐度，强光照，易蒸发的自然环境中生存的一种适应机制．

Effect of Salinity on Ultrastructure of Chloroplast in Dunaliella salina

The ultrastructure of chloroplast in Dunaliella salina is studied under varied concentrations of NaCl. The results show that the algal cell has a typical cup shaped chloroplast in the medium containing 2.7 mol/L NaCl. As the concentration of NaCl increases from 2.7 to 4.3 mol/L, the chloroplast breaks into sevaral either independent or contacting parts gradually; the thylakoid system is disintegrated and replaced by numerous osmiophilic plastoglobuli; some mitochondria appear among the chloroplasts. As concentration of NaCl decreases from 4.3 to 2.7 mol/L, the chloroplasts of the alga can resume progressively to a typical cup shaped structure. Therefore, the change of chloroplast of Dunaliella salina is a reversible process, such reversibility makes it possible that the alga can live under the hypersaline, high light and evaporative environments.