摘要
用透射电镜观察了“巨峰”葡萄(Vitis vinifera×V.labrusca)果实3个发育时期中果肉细胞超微结构的变化。果实第一次快速生长期的果肉细胞超微结构表现出物质和能量代谢旺盛的特点。缓慢生长期的果实虽外部形态平静少变,但果肉细胞超微结构表现出深刻的变化:细胞核形状特化为裂瓣状是最显著的特点;线粒体数目丰富;粗面内质网槽库膨大形成的囊泡富集,出现向液泡汇融和向质膜靠近的现象;质膜内陷;液泡膜完整。另外,原生质也出现一些降解的现象。但总体结构特点表明果肉细胞在此期处于十分活跃的物质周转代谢和信息交换过程中。果实第二次快速生长期果肉细胞超微结构表现出衰老降解的特点,但线粒体结构依然完整,数量仍然丰富,原生质膜也保持了很好的完整性,这似乎与维持第二次快速生长或成熟有关。
Systematic observation of the ultrastructural changes in the fruit mesocarp cells of the 'Kyoho' grapevine ( Vitis vinifera x V. labrusca) with transmission electron microscopy was conducted. The ultrastructure of a mesocarp cell during the developmental phase I (the first rapid growth phase) was mainly characterized by the following features: a large central vacuole; a compact cell wall with evenly stained material distributed in the wall, of which the middle lamella was not easily distinguishable; a electron-dense cytoplasm; a full nucleus of often banana-shaped; numerous highly developed mitochondria distributed around the plastids; plentiful tube-like rough endoplasmic reticula; a quantity of vesicles present in the protoplasm, within which many being coalesced and merged into the central vacuole; small vesicles traversed in array through some plasmadesmata; many developed chloroplast or plastids, within some of which were accumulated starch grains. All of these cellular ultrastructural characteristics during the phase I suggested the existence of a very active material and energy metabolism. During the developmental phase II (lag phase of berry growth) , the most marked ultrastructural changes in the mesocarp cells was a nuclear envelope in-vagination leading to the formation of the lamella or lobed nucleus with a higher electron density in the agglomerate karyoplasm than that in phase I , which was considered as an expansion of the interface between nucleus and cytoplasm so to facilitate the communication between them; some or- ganella such as mitochondria and plastids were wrapped in this lamella nucleus as a result of the in-vagination of cytoplasm to nucleus; the cytoplasm was less electron-dense than in phase I ; plenty of the mitochondria appeared to be distributed preferably around the nucleus and vesicles; a large number of vesicles formed from dilation of the rough endoplasmic reticulum cisterna merged into the central vacuole and occasionally were seen on the brink of plasma membrane; some circled
基金
国家自然科学基金
关键词
葡萄
果实
发育
果肉细胞
超微结构
Grapevine fruit, Developmental phase, Mesocarp cell, Ultrastructure
