The ontogeny of lipid bodies (spherosomes) in plant cells
The ontogeny of lipid bodies (spherosomes) in plant cells
复制标题
植物细胞中脂质体（球体）的个体发育
作者：
Gerhard Wanner;H. Formanek;R. R. Theimer
将16种油料植物的成熟胚、八角悬浮培养细胞和粗草神经孢子虫细胞在脂质大量积累的不同阶段进行电镜观察。通过在不含环氧丙烷的乙醇中脱水固定组织，包埋在Spurr's培养基中，并在室温下聚合，可以最好地保存某些物种的富脂结构。在所有被检查的细胞中，球形脂质体（球体）显示中等亲锇性，无定形基质，并在中间切片时显示分隔半单元膜。与内质网（ER）的联系在脂质体发育的任何阶段都被观察到，但在不同的植物物种中频率不同。脂肪储存细胞的质体呈现出明显的波状外膜和内膜，相互之间形成多个接触点，并在细胞质和基质中形成突起。一些物种，如亚麻属，具有管状结构的质体，将内膜与类囊体系统连接起来；此外，间质中可见囊泡与包膜融合或明显穿过包膜。外包膜可能与er样细胞质膜结构有关。此外，还发现与质体包膜接触的脂质体大小不一。超微结构观察结果与已发表的生化证据一致，表明质体和内质网都可能参与储存脂质的合成和脂质体的生产。
Maturing embryos of 16 oil plants, anise suspension culture cells, and Neurospora crassa cells were prepared for electron microscopy at different stages during massive lipid accumulation. Lipid-rich structures of certain species were best preserved by dehydration of fixed tissues in ethanol without propylene oxide, embedding in Spurr's Medium, and polymerization at room temperature. In all cells examined, spherical lipid bodies (spherosomes) showed a moderately osmiophilic, amorphous matrix and displayed a delimiting half-unit membrane when sectioned medially. Associations with the endoplasmic reticulum (ER) were viewed at any stage during lipid body development but with different frequency in the different plant species. Plastids of fat-storing cells exhibited conspicuously undulate outer and inner envelope membranes that formed multiple contact sites with each other and protuberances into both cytoplasm and stroma. Some species, e.g., Linum, have plastids with tubular structures that connect the inner membrane to the thylakoid system; in addition, in the stroma vesicles fusing with or apparently passing through the envelope were observed. The outer envelope membrane may be associated with ER-like cytoplasmic membrane structures. In addition, lipid bodies of various sizes were found in contact with the plastid envelope. The ultrastructural observations are interpreted to match the published biochemical evidence, indicating that both plastids and ER may be involved in the synthesis of storage lipids and lipid body production.