鹤顶兰胚囊发育过程中Ca^(2+)分布的超微细胞化学定位(英文)  

Ultracytochemical Localization of Calcium during Embryo Sac Development in Phaius tankervilliae(Orchidaceae)

作　　者：李冬妹[1,2] 王亚琴[3] 叶秀粦[2] 梁承邺[2] 

机构地区：[1]顺德职业技术学院,广东佛山528300 [2]中国科学院华南植物园,广东广州510650 [3]华南师范大学生命科学学院,广东广州510631

出　　处：《云南植物研究》2010年第6期495-502,共8页Acta Botanica Yunnanica

基　　金：Plan Project sponsored by the Depart ment of Science and Technology of Guangdong Province (2009B020405002)

摘　　要：用焦锑酸盐沉淀法对鹤顶兰(Phaius tankervilliae)胚囊发育过程中的Ca2+状态进行超微细胞化学定位。观察结果发现:功能大孢子时期,珠孔端的胚囊壁上开始出现小颗粒的Ca2+沉淀,但功能大孢子细胞内未见明显的Ca2+标记;四核胚囊时期胚囊壁上的Ca2+沉淀明显增多,液泡膜上有Ca2+沉淀出现,珠孔处的Ca2+沉淀颗粒较大;成熟胚囊时期,胚囊壁上的Ca2+沉淀进一步增多,且胚囊内Ca2+分布明显增多,且极性明显,珠孔端助细胞、卵细胞比合点端反足细胞有更多的Ca2+沉淀。鹤顶兰成熟胚囊内Ca2+积累的来源有:(1)在胚囊成熟前主要由珠被细胞、珠细胞通过胞间连丝向胚囊运输;(2)以沉淀有大量Ca2+的小泡形式跨过胚囊壁进入胚囊。Ultracytochemical localization of calcium in embryo sac of Phaius tankervilliae（Aiton） Bl. was carried out using potassium pyroantimonate precipitation method. Results of Ca2＋ distribution during embryo sac development are as following：（1） Megasporocyte stage：There is no Ca2＋ precipitation in the megasporocyte,nucellar cell and micropyle; （2） Functional megaspore stage：Small particles of Ca2＋ precipitates appear on the embryo sac wall at the micropylar end,but no apparent Ca2＋ can be found in the functional megaspore; （3） 4-nucleate stage：There are significant increase of Ca2＋ precipitation on the embryo sac wall and large grains of the precipitates in the micropyle,while a little starts to appear on the membrane of vacuole; （4） 8-nucleate embryo sac stage：Ca2＋ precipitation continuously increases on the embryo sac wall. Distribution of Ca2＋ in embryo sac shows strong polarity. More Ca2＋ precipitations are observed in the synergids and the egg cell than the antipodal cells. Accumulation of Ca2＋ precipitation is achieved by （1） transferring Ca2＋ to embryo sac through the plasmodesmata between the nucellar cells,which mainly occurred at the chalaza end before the embryo matured; （2） forming large amounts of small bubbles of Ca2＋ precipitation,which can cross embryo sac wall to enter embryo sac.

关 键 词：鹤顶兰 胚囊 超微细胞化学定位 焦锑酸盐沉淀法 钙 

分 类 号：Q944.4[生物学—植物学]