摘要
运用常规ATP酶超微细胞化学定位技术,对宁夏枸杞果实发育不同阶段的韧皮部和果肉库薄壁细胞ATP酶分布进行了观察研究。结果显示,在果实发育过程中SE/CC复合体与周围韧皮薄壁细胞间存在共质体隔离,韧皮薄壁细胞及果肉库薄壁细胞的胞间连丝较少,但是与果肉库薄壁细胞相邻的韧皮薄壁细胞的胞间连丝较多。囊泡和膜泡在筛管、韧皮薄壁细胞和库薄壁细胞中很丰富,并且质膜、囊泡膜、液泡膜上ATP酶沉淀物在韧皮部各细胞分布较少,在果肉库薄壁细胞分布较多,特别是在果实第二次快速生长期,果肉库薄壁细胞膜系统、细胞壁和胞间隙的ATP酶活性剧烈增强。此外,果肉库薄壁细胞的质膜ATP酶具极性分布特点。由此得出,枸杞果实韧皮部卸载是一种需要能量驱动的过程,其卸载途径主要以质外体途径为主,在从韧皮部向果肉库薄壁细胞卸出时可能为共质体和质外体途径共存。膜泡运输是枸杞果实同化物卸出和转运的重要方式,而韧皮薄壁细胞在同化物卸出和转运过程中承担了主要转运角色;果肉库薄壁细胞进行主动和定向卸载、积累同化物的能力很强。
The distribution of ATPase in phloem and the flesh sink-cells during fruit development of Lycium barbarum L. was studied by the conventional ATPase cytochemical positioning technology. This study aims at a better insight into the phloem unloading pathway in fruit of Lycium barbarum L. The results showed that there was a symplasmically isolation between the SE-CC complex and its surrounding cells over the fruit development. And there were less plasmodesmata among the phloem parenchyma cells and the flesh sink-cells. However, there were more plasmodesmata in phloem parenchyma cells adjacent the flesh sinkcells. Numerous vesicles and membrane bubbles were found in the sieve element, phloem parenchyma cells and the flesh sink-cells. The ATPase sediments of the plasma membrane, vesicle membrane and tonoplast were higher in the flesh sink-cells than that in the phloem parenchyma cells,especially in the second rapid growth of fruit,and during this time the ATPase activity wasdramatically increased on the membrane system of the flesh sink-cells,cell wall and the intercellular space. The distribution of the ATPase on the plasma membrane of the flesh sink-cells appeared polarity characteristics. It is considered that the phloem unloading is energy-driven process and the apoplastic route is the main pathway of the assimilate unloading over fruit development. However, symplastic and apoplastic pathway may coexist during assimilate unloading from the phloem to the flesh sink-cells. The vesicular transport is the important way of the fruit assimilates unloading and transfer. The phloem parenchyma cells perform the main transport role during the assimilate unloading and transfer. The flesh sink cells possess strong active transport and transit-oriented capacity in assimilates accumulation.
出处
《西北植物学报》
CAS
CSCD
北大核心
2009年第8期1568-1577,共10页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然基金项目(30500653)
宁夏大学自然科学基金资助
关键词
枸杞
果实
ATP酶定位
Lycium barbarum L.
fruit
ATPase localization
