Ca^(2+)-homeostasis Differs Between Plant Species with Different Cold-tolerance at 4 ℃ Chilling  

低温逆境中不同抗寒性植物细胞内Ca^(2+)稳定平衡的区别(英文)

作　　者：简令成[1] 孙龙华[1] 李积宏[2] 王红[1] 孙德兰[1] Paul HLI 

机构地区：[1]中国科学院植物研究所,北京100093 [2]Laboratory of Plant Hardiness,Department of Horticultural Science and Plant Biological Sciences Program,University of Minnesota,St.Paul

出　　处：《Acta Botanica Sinica》2000年第4期358-366,共9页Acta Botanica Sinica（植物学报：英文版）

基　　金：TheNationalNaturalScienceFoundationofChina!( 39870 371 )

摘　　要：A comparative study was carried out on the EM_cytochemical localization of calcium and Ca 2+ _ATPase activity in the suspension_cultured cells between the chilling_sensitive maize ( Zea mays L. cv. Black Mexican Sweet) and chilling_insensitive Trititrigia ( Triticum sect. Trititrigia mackey) at 4 ℃ chilling. When maize and Tyititrigia cells were cultured at 26 ℃, electron microscopic observations revealed that the electron_dense calcium antimonate deposits, an indication of the calcium localization, were localized mainly in the vacuoles, and few was found in the cytosol and nuclei. The electron_dense cerium phosphate deposits, an indication of Ca 2+ _ATPase activity, were abundantly distributed on the plasma membrane (PM). When the cells from both species were cultured at 4 ℃ for 1 and 3 h, an elevation of Ca 2+ level in the cytosol and nuclei was observed, whereas the cerium phosphate deposits on the PM showed no quantitative difference from those of the 26 ℃_cultured cells, indicating that the enzymatic activities were not altered during these chilling periods. However, there was a distinct difference in the dynamics of the Ca 2+ distribution and the PM Ca 2+ _ATPase activity between maize and Trititrigia when chilled at 4 ℃ for 12, 24 and 72 h. In maize cells, a large number of Ca 2+ deposits still existed in the cytosol and nuclei, and the PM Ca 2+ _ATPase became less and less active, and even inactive at all. In Trititrigia cells, the increased cytosolic and nuclear Ca 2+ ions decreased after 12 h chilling. By chilling up to 24 and 72 h, the intracellular Ca 2+ concentration had been restored to a similar low level as those of the warm temperature_cultured cells, while the activity of the PM Ca 2+ _ATPase maintained high. The transient cytosolic and nuclear Ca 2+ increase and the activities of PM Ca 2+ _ATPase during chilling are discussed in relation to plant cold hardiness.电镜细胞化学观察揭示 ,不抗寒的玉米 (ZeamaysL .cv.BlackMexicanSweet)和抗寒的小偃麦 (Triticumsect.Trititrigiamackey)细胞在 2 6℃悬浮培养时 ,标志Ca2 + 定位的锑酸钙沉淀物主要分布在液泡内 ,细胞质和细胞核中很少见到Ca2 + 沉淀 ;标志Ca2 + _ATPase活性反应的磷酸铈沉淀物丰富地分布在质膜上 ,显示这两种植物质膜Ca2 + _ATPase在 2 6℃培养中有着较高的活性。当这二者的细胞在 4℃低温培养 1h和 3h后 ,二者细胞质和细胞核中的Ca2 + 浓度都明显地增加 ,但质膜Ca2 + _ATPase活性没有明显改变。在继续延长低温培养后 ,二者之间的Ca2 +水平和Ca2 + _ATPase活性发生明显的区别 :在不抗寒的玉米细胞中 ,质膜Ca2 + _ATPase活性显著降低 ,甚至完全失活 ,细胞内增加的Ca2 + 水平不降低 ,不能恢复Ca2 + 的稳定平衡 ,细胞的精细结构受破坏 ;抗寒的小偃麦细胞则相反 ,在 3h以后的低温培养过程中 (至 3d) ,质膜Ca2 + _ATPase仍然保持高活性 ,细胞内增加的Ca2 + 浓度迅速降低 ,恢复Ca2 + 的稳定平衡 ,并提高抗寒力。这些结果表明 ,植物在低温条件下 ,质膜Ca2 + _ATPase活性的维持亦即细胞内Ca2 + 稳定平衡的恢复与其抗寒性有着密切的关系 ,对于它们在逆境中生存起着重要作用。

关 键 词：Ca    2+ plasmalemma Ca    2+  _ATPase Ca    2+  _homeostasis plant cold  hardiness maize Trititrigia 

分 类 号：Q945.78[生物学—植物学]