淹水玉米幼苗根尖分生细胞内Ca^(2+)超微细胞化学定位

Ultrastructural localization of Ca^(2+) in primary root meristemic apical meristemic cells of the flooded maize.

采用焦锑酸钾沉淀法,对遭受淹水胁迫的玉米幼苗初生根根尖分生细胞内钙离子分布变化情况进行了电镜细胞化学观察。在正常状态下,根尖分生细胞内Ca2+沉淀颗粒的分布较少,主要位于细胞核和细胞质中。在淹水1h后,根尖分生细胞内呈现有大量Ca2+沉淀颗粒分布,细胞核和细胞质中分布的Ca2+沉淀颗粒密度,远大于正常细胞。随着淹水时间的延长,根尖分生细胞的细胞核和细胞质中分布的Ca2+沉淀颗粒呈现不断增多的趋势,而液泡中分布的Ca2+沉淀颗粒则逐步明显减少。根据实验结果本文对受淹根尖分生细胞的死亡与Ca2+分布变化的关系进行了研究。

Potassium antimonate was employed to ultrastructurally locate calcium ions in seminal root apical meristematic cell of maize seedings subjected to flooding stress. In the normal root apical cells, only a few calcium precipitates was observ ,mainly located in nucleus and cytoplasm. After 1 h under flooding, antimonate calcium deposits appeared to be dramastically increased in nucleus and especially in cytoplasm. With the prolongation of flooding treatment to 12h and 24h irrspectively, the calcium precipitates showed further increased in nucleus and cytoplasm, but significantly decreased in vacuoles. According to the resuits, the relationship between the change in distribution of calcium ions and disgradation of the flooded maize root apical meristematie cells was discussed.