小麦受精过程中酸性磷酸酶的超微细胞化学定位

小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ ）受精前成熟胚囊，除胚囊中央细胞的合点端细胞质中有酸性磷酸酶外，其余部位均未发现酸性磷酸酶。受精时期，以下部位存在酸性磷酸酶活性：卵细胞的细胞核内一部分染色质和细胞质中大部分线粒体；精、卵核融合时两核的核周腔内；退化助细胞合点端细胞质和一些液泡内；进入雌性细胞中的两个精核；胚囊各成员细胞的细胞壁及胚囊周围珠心细胞的细胞壁。二细胞原胚中未见有酸性磷酸酶。早期胚乳游离核染色质上有酸性磷酸酶。小麦受精过程酸性磷酸酶的分布特点可能与卵细胞生理状态的变化和细胞质中线粒体的改组、助细胞的退化、精核的生理状态以及精核与卵核的核膜融合等有关。

THE ULTRACYTOCHEMICAL LOCALIZATION OF ACID PHOSPHATASE ACTIVITY IN WHEAT DURING FERTILIZATION

No acid phosphatase activity was observed in the mature embryo sac of wheat (Triticum aestivum) except the chalazal cytoplasm of the central cell before fertilization. During fertilization, acid phosphatase activity was observed in the following loci: part of chromatin of the egg nucleus and most of the mitochondria in the egg cytoplasm; the perinuclear spaces of the egg and sperm nuclei at the fusion of the egg and sperm nuclei; the chalazal cytoplasm and some vacuoles of the degenerated synergid; two sperm nuclei within the cytoplasm of female cells; the cell wall of each cell of the embryo sac and that of the nucellar cells surrounding the embryo sac. No acid phosphatase was observed in the two celled proembryo.Dense enzyme reaction product was localized in the chromatin of the free nuclei at early stage of the endosperm. The characteristic of acid phosphatase distribution during fertilization may be associated with the physiological change of the egg Cell, the reorganization of mitochondria in the egg cell cytoplasm, the degeneration of one of the two synergids, the physiological state of the sperm nuclei and the nuclear membrane fusion of the egg and sperm nuclei.