西瓜胚乳吸器的发育及ATP酶的超微细胞化学定位

The development of endosperm haustorium and the ultracytochemic localization of ATPase activity in the haustorium of watermelon

报道了西瓜 (Citrullus lanatus)胚乳吸器发育过程 ,并对胚乳吸器细胞中的 ATP酶进行了超微细胞化学定位。球形胚早期 ,胚囊合点端的壁伸长发育成一管状胚乳吸器 ,进而吸器靠近胚乳本体端膨大为囊状。球形胚晚期吸器自珠孔端向合点端逐渐细胞化。胚分化出子叶时 ,胚乳吸器自合点端向珠孔端退化。在刚形成的胚乳吸器细胞中 ,ATP酶活性反应主要分布在细胞的核膜、内质网上 ,胞间连丝和吸器细胞壁内的小球状物上也有较强的 ATP酶活性反应 ;在开始退化的吸器细胞中 ,核膜上的 ATP酶活性的反应减弱较早 ,内质网稍晚 ;进一步退化的胚乳吸器细胞中 ,ATP酶主要集中分布在细胞壁、细胞间隙内。核膜上几乎没有ATP酶活性反应 ,内质网上仅有微弱的 ATP酶反应。

The development of endosperm haustorium in watermelon ( Citrullus lanatus ) was observed,and the ultracytochemical localization of ATPase activity was carried out in the endosperm haustorium cells.At the early globular embryo,the chalazal portion of the embryo sac grown into tubular haustorium,which still remained coenocytic.The haustorium cellularizated from the micropylar end to chalazal end at the later globular stage.When the embryo differentiated cotyledons,the haustorium cells gradually degenerated,then disappear.ATPase activity was mostly located on nucleus membrane,ERs and bulb like substances in wall of endosperm haustorium cells.When the haustorium cell began to degenerate,the reaction of ATPase activity on nucleus membrane is markedly reduced.With the degeneration of the endosperm haustorium,the high activity reaction of ATPase was almost localized in cell wall and intercellular spaces of haustorium cells,while the ATPase activity on nucleus membrane was hardly to see and a little enzyme activity was observed on ERs.