小麦幼苗质膜Mg^(2+)-ATP酶活性与低温损伤及其恢复的关系

The relationship of the plasma membrane Mg 2+ ATPase activity in wheat seedlings to low temperature injury and recovery

采用氯化铈（ＣｅＣｌ３）沉淀的电镜细胞化学方法观测了小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）幼叶细胞质膜三磷酸腺苷酶活性在低温胁迫后、恢复过程中以及恢复后的变化。所得主要结果如下：（１）在正常温度（２０℃）下生长的小麦幼苗，其幼叶细胞内的三磷酸腺苷酶主要定位于质膜、细胞壁和细胞间隙等处，其中以质膜上的酶活性最强。（２）小麦幼苗在－２℃处理１６ｈ后未经恢复生长即固定，此时质膜上的ＡＴＰａｓｅ活性明显降低或失活，细胞的超微结构也受到破坏。（３）小麦幼苗经－２℃低温胁迫１６ｈ后，并经过２４ｈ的恢复生长，此时质膜的ＡＴＰ酶活性有了很大程度的恢复；小麦幼苗在－２℃低温下处理１６ｈ后，经１５０ｍｍｏｌ／ＬＣａＣｌ２溶液处理，并经２４ｈ的恢复生长，此时质膜上的ＡＴＰ酶活性比未用ＣａＣｌ２处理时增强；小麦幼苗经－２℃低温处理１６ｈ后，经１００ｍｍｏｌ／ＬＮａ３ＶＯ４（钒酸钠）处理，也经过２４ｈ的恢复生长，此时质膜上观察不到ＡＴＰａｓｅ的活性反应，同时细胞的超微结构受到严重破坏。（４）小麦幼苗在－２℃处理１６ｈ后，经过７２ｈ的恢复生长，质膜上的ＡＴＰａｓｅ活性基本恢复到正常水平，同时小麦幼苗也基本恢复正常生长。

In this paper,the changes of ATPase activities in the cells of wheat ( Triticum aestivum L. ) seedlings right after low temperature stress,during the period of recovery,and after the recovery were studied using cytochemical method of cerium trichloride precipitates,the main results are summarized as follows: 1). Wheat seedlings grew at the optimum temperature (20℃):The ATPase in young leaves cells of the wheat seedlings mainly concentrated on plasmolemma,cell wall and intercellular spaces.Among these 3 places,the ATPase in plasmolemma manifested the highest activity. 2). After being treated at the temperature of -2℃ for 16 hrs,wheat seedlings were fixed immediately:In comparison with the non treated seedlings,the ATPase activities in plasmolemma significantly decreased or inactivated and the cells′ ultrastructures were damaged. 3). Wheat seedlings were treated at the low temperature of -2℃ for 16 hrs,then followed by a recovery period of 24 hrs:In comparison with the seedlings without such a recovery period,the ATPase activities in plasmolemma recovered in a large degree. 4). Wheat seedlings were treated at the temperature of -2℃ for 16 hrs,then being treated with 100mmol/L CaCl 2 solute,and followed by a recovery period of 24 hrs:In comparison with the seedlings non treated with CaCl 2 solute,the ATPase activities in plasmolemma increased. 5). Wheat seedlings were treated at the temperature of -2℃ for 16 hrs,then treated with 100 mmol/L Na 3VO 4 solute,and followed by a recovery period of 24 hrs:In comparison with the seedlings non treated with Na 3VO 4 solute,the ATPase activities in plasmolemma were lost completely and the cells ultrastructures were severely damaged. 6). Wheat seedlings were treated at the temperature of -2℃ for 16 hrs,then followed by a recovery period of 72 hrs:The ATPase activities in plasmolemma recovered to the normal level and the growth of the seedlings also recovered to the normal level.