Tzen J T, Peng C C, Cheng D J, Chen E C, Chiu J M
Graduate Institute of Agricultural Biotechnology, National Chung-Hsing University, Taichung, Taiwan.
J Biochem. 1997 Apr;121(4):762-8. doi: 10.1093/oxfordjournals.jbchem.a021651.
Plant seeds store triacylglycerols as energy sources for germination and postgerminative growth of seedlings. The triacylglycerols are preserved in small, discrete, intracellular organelles called oil bodies. A new method was developed to purify seed oil bodies. The method included extraction, flotation by centrifugation, detergent washing, ionic elution, treatment with a chaotropic agent, and integrity testing by use of hexane. These processes subsequently removed non-specifically associated or trapped proteins within the oil bodies. Oil bodies purified by this method maintained their integrity and displayed electrostatic repulsion and steric hindrance on their surface. Compared with the previous procedure, this method allowed higher purification of oil bodies, as demonstrated by SDS-PAGE using five species of oilseeds. Oil bodies purified from sesame were further analyzed by two-dimensional gel electrophoresis and revealed two potential oleosin isoforms. The integrity of oil bodies in germinating sesame seedlings was examined by hexane extraction. Our results indicated that consumption of triacylglycerols reduced gradually the total amount of oil bodies in seedlings, whereas no alteration was observed in the integrity of remaining oil bodies. This observation implies that oil bodies in germinating seeds are not degraded simultaneously. It is suggested that glyoxisomes, with the assistance of mitochondria, fuse and digest oil bodies one at a time, while the remaining oil bodies are preserved intact during the whole period of germination.
植物种子储存三酰甘油作为种子萌发和幼苗萌发后生长的能量来源。三酰甘油保存在称为油体的小型、离散的细胞内细胞器中。一种纯化种子油体的新方法被开发出来。该方法包括提取、离心浮选、洗涤剂洗涤、离子洗脱、用离液剂处理以及使用己烷进行完整性测试。这些过程随后去除了油体内非特异性结合或捕获的蛋白质。通过这种方法纯化的油体保持了它们的完整性，并在其表面表现出静电排斥和空间位阻。与之前的方法相比，如使用五种油籽的SDS-PAGE所示，该方法能够更高程度地纯化油体。从芝麻中纯化的油体通过二维凝胶电泳进一步分析，揭示了两种潜在的油质蛋白同工型。通过己烷提取检查了萌发芝麻幼苗中油体的完整性。我们的结果表明，三酰甘油的消耗逐渐减少了幼苗中油体的总量，而剩余油体的完整性未观察到改变。这一观察结果表明，萌发种子中的油体不是同时降解的。有人提出，乙醛酸循环体在线粒体的协助下，一次融合并消化一个油体，而剩余的油体在整个萌发期间保持完整。
