【摘要】 用胶体免疫金电镜技术观察了受精前后烟草（Nicotianatabacumvarmacrophylla）卵细胞内玉米素（t－Z）、GA7与GA4、（＋）ABA与IAA分布的变化。受精前卵细胞内有大量t－Z，主要位于细胞核、内质网与线粒体上；与卵细胞相邻的助细胞合点端及中央细胞珠孔端亦有较多t-Z。受精后，合子与宿存助细胞t－z显著减少，正加厚的合子细胞壁中有t－Z分布。未受精卵细胞内GA7与GA4及（＋）ABA减少，IAA更少。合子内GA7与GA4及（＋）ABA略有增加，IAA仍然很少。初步讨论了上述植物激素与受精作用的关系。更多还原

【Abstract】 Changes in distribution Of trans-zeatin （t-Z）, gibberellin A₇ and A₄ （GA（7/4））, （+） abscisic acid [ （+ ）ABA] and indoleacetic acid （IAA） in the egg cells of Nicotiana tabacum var. macrophylla before and after fertilization were studied with immunoelectron microscopy. The ovules just at pollination or 96 h after pollination were fixed with 2% EDC [1 - ethyl- 3 - （3 - dimethylaminopropy1 ） carbodiimide ] and then with the mixed paraformaldehyde and glutaraldehyde for acidic phytohormones （or only with the aldehydes for t-Z）, then slightly postfixed in O.5% OsO4 solution for 30 min. Afer etched in 1 % H2O2 for 10 min, the ultrathin sections embedded in Epon 812 resin were immunostained with rabbit anti-t-Z （and t-ZR） polyclonal antibody （PAB）, anti-IAA methyl ester PAb, mouse anti-GA7 and GA4 methyl esters monoclonal antibody（MAb）, or ani-（+） ABA methyl ester MAb, respectively. Protein A- or sheep anti-mouse IgG-colloidal gold （Φ10 nm）were used to indicate hobit PAbs or mouse MAbs respectively. In the model system of nitrocellulose membrane via immnogold-silver enhancement, the authors ascertained that immunostaining results at the basis of 1 ng per phytohormone （t-Z, IAA, GA4, or （+）ABA） were comparable among the four-kind phytohormones and that t-Z riboside was far less fixed than t-Z with aldehydes. So the anti-t-Z PAb mainly recognized t-Z in aldehyde-fixed tissues. Immunoogold electron microscopic observations showed that t-Z was rich in the egg cells before fertilization. In contrast the amounts of GA（7/4） and （+）ABA were lower in egg cells before fertilization but slightly increased after fertilization- Less IAA in egg cells was found either before or after fertilization. t-Z in unfertilized egg cells appeared to concentrate on the nucleus, endoplasmic reticultum and mitochondria. t-Z is rarely observed in the nuclei of synergids before fertilization but is abundant in the chalazal end of synergids and micropylar end of the central cell adjacent to the unfertilized egg cell. Afer fertilization, t-Z decreased obviously in the zygotes and the persistent synergids, but appeared in the thickened walls of the zygotes.更多还原