小麦雌配子体发育过程中酸性磷酸酶活性定位

LOCALIZATION OF ACID PHOSPHATASE ACTIVITY DURING DEVELOPMENT OF MEGAGAMETOPHYTE IN WHEAT

在小麦(Triticum aestivum L.)雌配子体发育过程中,胚囊周围邻近的珠心细胞退化降解,并出现很高的酸性磷酸酶反应,特别是合点部分最强。电镜细胞化学定位也表明退化珠心细胞质中有强烈的酸性磷酸酶活力,它们存在于多层环状的胞质结构中,而远离胚囊的非退化珠心细胞中无上述结构,酸性磷酸酶活性仅出现于液泡中。认为珠心细胞的退化是一种自溶现象。从功能大孢子至七细胞胚囊期,胚囊内部胞质酸性磷酸酶活性很低,合点与珠孔两端的反应强度无明显区別。后期成熟胚囊阶段,反足细胞中出现强烈酸性磷酸酶活性,中央细胞次之,而助细胞及卵细胞中很弱。

During development of megagametophyte in wheat(Triticum aestivum L.), the nucellar cells adjacent to the embryo sac degenerated and showed high ACPase activity, especially at the chalazal end. High activity of ACPase was observed in the multiple concentric structures in the degenerating cytoplasm, but such structures were not present in the undegenerated nucellar cells. Therefore, the degeneration of these cells was an autolytic process rather than a result of mechanical pressure from the adjacent growing cells. Little ACPase was localized ia the cytoplasm from functional megaspore to 7-celled embryo sac stage, and striking difference was not observed between its two ends. However, in various cells of the mature embryo sac at late stage, the ACPase reaction showed very great differentiations.