渗透胁迫下玉米幼叶细胞Ca~(2+)分布及超微结构变化

采用改进的焦锑酸钙沉淀细胞化学方法,探讨了渗透胁迫条件下玉米幼叶胞内Ca2+的分布及细胞超微结构的变化,旨在进一步探讨Ca2+与渗透胁迫诱导胞内信息转导过程的关系。结果表明:干旱胁迫初期,胞质Ca2+浓度升高,液泡失水,叶绿体、细胞核Ca2+浓度升高,起到了调节胞内Ca2+浓度的作用;随着胁迫时间的延长,细胞超微结构遭到破坏,同时,叶绿体及细胞核中Ca2+浓度呈继续上升趋势,二者超微结构受到破坏的程度愈发严重,直至解体。说明:Ca2+介导了渗透胁迫诱导的细胞生理过程,Ca2+对细胞核骨架的可塑性发挥着重要作用。

The changes of Ca2+ localization in cells and cytological electromicroscopic structure of Zea mays L. leaflets under osmotic stress

In order to study the relationship between cytosolic Ca2 and physiological process triggered by osmotic stress,the changes of Ca2 localization in cells and cytological electromicroscopic strcture of mays leaflets under PEG6000 stress were investigated with calcium antimorate precipitate-electron microscopic-cyrochemical metrods.It was shown that at the beginning of the stress,the free in cytoplasm was increased.With the water lost in vacuoles,the level of Ca2 both chloroplast and nucleus were increased considerably,and as the pool of calcium,both of two organelles played an important role in regulating the concentration of Ca2 in cytoplasm.With the longer of osmotic stress,the ultrastructure of cells were damaged,the Ca2 both chloroplast and nucleus were increased more,the ultrastrcture of the two organelles were damaged seriously,and then depolymerized.This indicated that Ca2 intervened in the physiological process induced by osmotic stress,and it played an important role in regulating nucleus frame change.