灵武长枣果实ATPase超微细胞化学定位和功能研究

Cytochemical Localization and Functional Analysis of ATPase during Fruit Development of Ziziphus jujuba Mill.cv. lingwuchangzao

采用ATPase超微细胞化学定位技术,研究灵武长枣果实不同发育阶段韧皮部和果肉库薄壁细胞ATPase分布特征,以明确灵武长枣果实ATPase超微细胞化学定位特征和功能。结果显示:(1)第一次快速生长期SE/CC复合体与周围的薄壁细胞有丰富的胞间连丝,形成共质体连续,韧皮部薄壁细胞之间有丰富的胞间连丝,ATPase反应物在韧皮部各细胞分布较少。(2)缓慢生长期ATPase反应物在韧皮部各细胞分布逐渐增加。(3)第二次快速生长期SE/CC复合体与周围的薄壁细胞缺乏胞间连丝,形成共质体隔离,韧皮薄壁细胞及果肉库薄壁细胞的胞间连丝较少,囊泡和膜泡在筛管、韧皮薄壁细胞和库薄壁细胞中很丰富,质膜、液泡膜、囊泡膜、细胞壁和胞间隙的ATPase活性较高。研究表明,果实在第一次快速生长期同化物从筛分子的卸出主要采取共质体途径,缓慢生长期同化物卸出时可能为共质体和质外体途径共存,第二次快速生长期则主要以质外体途径为主,证明果实不同发育阶段韧皮部同化物卸出路径存在差异。

The distribution characteristics of ATPase in phloem and the flesh sink-cells of fruit in different developmental stages of Ziziphus jujuba Mill. cv. Lingwuchangzao were studied by ATPase ultracytochem- ical location technology. The result showed that ： （1） In the first rapid growth of fruit, there were abundant plasmodesmata in the SE-CC complex and its surrounding cells, making the phloem a symplastic integration. There were abundant plasmodesmata in the phloem parenchyma cells, but there were less ATPase sed iments in various ceils of phloem. （2）In the slower growth period,the distribution of ATPase sediments in various cells of phloem increased gradually. （3）In the second rapid growth of fruit, there were less plasmodesmata between the SE-CC complex and its surrounding parenchyma cells, resulting in the symplastic isolation between them. There were less plasmodesmata in phloem parenchyma cells and the flesh sink- cells,numerous vesicles and membrane bubbles were found in the sieve tube,phloem parenchyma cells and the flesh sink-cells. The ATPase activities were higher in plasma membrane, vacuole membrane, vesicle membrane, cell wall and intercellular space. To sum up,the photoassimilates unloading from sieve tube ele- ment was symplast pathway in the first rapid growth of fruit;the symplast pathway and apoplastic pathway existed simultaneously in the slower growth period^the photoassimilates unloading adopted mainly apoplastic pathway in the second rapid growth of fruit. The photoassimilates unloading pathway in phloem existeddifferences in different developmental stages of fruit.