抗寒剂CR-4 对冬小麦幼苗质膜钙泵（Ca2 +-ATPase） 的稳定作用

通过磷酸铈沉淀的细胞化学观察揭示，常温下生长的冬小麦幼苗的Ca2+ -ATP酶活性主要定位在质膜上，同时，水浸种和抗寒剂浸种的小麦质膜Ca2+ -ATP酶活性没有差异。然而，小麦幼苗经-7℃冰冻处理12小时和24小时后，则表现明显的区别：水浸种的小麦幼苗质膜Ca2+ -ATP酶活性明显下降，直至完全失活，细胞的精细结构也同时被破坏；而经抗寒剂浸种的小麦幼苗质膜Ca2+ -ATP酶仍维持较高的活性，细胞结构也保持完整，显示抗寒剂对质膜Ca2+ -ATPase酶起着明显的稳定作用。

The Stabilizaton on the Plasmalemma Calcium-Pump( Ca2 + -ATPase) in Winter Wheat Seedlings by the Cold-Resistant Agent CR-4

The electron microscopical observations using Cytochemical method of cerium phosphate precipitation indicated that the Ca2+-ATPase activity was mainly localized at the plasmalemma in wheat seedling cells grown at normal temperature. And the enzyme activity did not appear to be different between water-soaked and CR4-Soaked treatments under normal temperature. However, the differences occurred when wheat seedlings were treated for 12 hrs and 24 hrs at - 7℃: the plasmalemma Ca2+-ATPase activity in the seedlings from water-soaked seeds was markedly decreased, and the ultrastructures were disrupted, and that from cold-resistant agent CR4-Soakod seeds was still maintained, and their free structures were also intact. The results suggest that the cold-resistant agent CR-4 plays an important role for stabilizing plasmalemma calcium pump (Ca2+-ATPase) under low temperature stress.