荔枝雌蕊发育过程中钙分布变化与细胞程序性死亡(英文)  

Distribution Changes of Calcium and Programmed Cell Death in the Pistil of Litchi (Litchi chinensis Sonn.) Flower during Its Development

作　　者：王湘平[1] 苏力寻[2] 苏金为[3] 

机构地区：[1]福建农林大学测试中心,福州350002 [2]厦门大学生命科学学院,厦门361005 [3]福建农林大学生命科学学院,福州350002

出　　处：《植物生理与分子生物学学报》2006年第6期607-616,共10页Journal Of Plant Physiology and Molecular Biology

基　　金：福建省自然科学基金项目(No.B0310013)资助。~~

摘　　要：应用焦锑酸钾沉淀法研究了荔枝雌花和雄花雌蕊发育过程中钙的分布变化。在大孢子母细胞阶段,雌花近珠孔内珠被细胞和花柱细胞的钙沉淀颗粒主要分布在细胞壁和细胞间隙,少部分在液泡;雌花花柱维管细胞中含有很多的钙沉淀颗粒;在雄花的近珠孔内珠被细胞钙沉淀颗粒大多在液泡中;雄花花柱细胞和维管细胞中钙沉淀颗粒很少。大孢子母细胞减数分裂后,雌花雌蕊继续发育,雄花雌蕊败育。雌花维管中的钙沉淀颗粒数量减少,可能被转运到将要发生花粉萌发和受精的部位。雌花近珠孔内珠被细胞壁的钙沉淀颗粒分布增加,花柱细胞从上(近柱头)到下(近子房)钙沉淀颗粒量递增。雄花近珠孔内珠被细胞发生程序性死亡:液泡中的钙进入细胞核启动细胞程序性死亡,核周隙与质膜腔形成连续的通道,钙在核与细胞质之间的流动不受限制;在特定的时间段,钙沉淀颗粒出现在线粒体、过氧化物体和线型内质网的外膜上。钙在细胞中重新分布可能触发和调节细胞程序性死亡的进程。缺乏钙沉淀颗粒的雄花花柱细胞迅速解体。Potassium pyroantimonate precipitation method was used for investigating calcium distribution and cell ultrastructure change during development of pistils of litchi male and female flower. The results showed that at the megasporocyte stage of female flowers, calcium precipitates was located mainly at cell wall and intercellular space of inner integument near the micropyle and style cells, and to a lesser extent in vacuoles. Vascular tissues also contained much calcium precipitates. In inner integument cells near the micropyle of male flowers, the vacuole contained most of the calcium precipitates. Calcium precipitates in style cell and vascular tissues of male flowers was sparse and seldom seen. After meiosis of megasporocyte, pistils of female flowers continued to grow and those of male flowers aborted. In female flowers, calcium precipitates concentration became lower and calcium precipitates was probably transported to the places for future pollen bourgeoning and fertilization. Cell wall calcium precipitates concentration increased in the inner integument cells near the micropyle. Calcium precipitates concentration increased from topper style cells to lower ones. In male flowers, inner integument cells near the micropyle underwent the programmed cell death （PCD）： flow of calcium from vacuoles into nucleus might had triggered the PCD process. A continuous channel was formed between perinuclear space and cytoplasm membrane lumen, and calcium flowed freely between nuclear membrane and plasma membrane. At certain time and locations, calcium precipitates was newly appeared at some organelles like endoplasimic reticulum, mitochondria and peroxisomes. This calcium redistribution in cells might trigger and regulate the process of PCD. In male flowers, style cells containing no calcium precipitation soon began to degenerate.

关 键 词：钙离子 荔枝 雌蕊发育 细胞程序性死亡 超微细胞化学定位 

分 类 号：Q945[生物学—植物学]