Department of Biology, University of California/San Diego, C-016, 92093, La Jolla, CA, USA.
Planta. 1985 Jun;164(3):295-302. doi: 10.1007/BF00402940.
Development of legume seeds is accompanied by the synthesis of storage proteins and lectins, and the deposition of these proteins in protein-storage vacuoles (protein bodies). We examined the subcellular distribution, in developing seeds of the common bean, Phaseolus vulgaris L., of the major storage protein (phaseolin) and the major lectin (phytohemagglutinin, PHA). The proteins were localized using an indirect immunocytochemical method in which ultrathin frozen sections were immunolabeled with rabbit antibodies specific for either PHA or phaseolin. Bound antibodies were then localized using goat-anti-rabbit immunoglobulin G adsorbed onto 4- to 5-nm colloidal gold particles. The sections were post-fixed with OsO4, dehydrated, and embedded in plastic on the grids. Both PHA and phaseolin exhibited a similar distribution in the storage-parenchyma cells, being found primarily in the developing protein bodies. Endoplasmic reticulum and Golgi complexes (cisternal stacks and associated vesicles) also were specifically labeled for both proteins, whereas the cytosol and other organelles, such as mitochondria, were not. We interpret these observations as supporting the hypothesis that the transport of storage proteins and lectins from their site of synthesis, the rough endoplasmic reticulum, to their site of deposition, the protein bodies, is mediated by the Golgi complex.
豆科植物种子的发育伴随着储存蛋白和凝集素的合成，以及这些蛋白在蛋白储存液泡（蛋白体）中的沉积。我们研究了普通菜豆（Phaseolus vulgaris L.）发育种子中主要储存蛋白（菜豆球蛋白）和主要凝集素（植物血球凝集素，PHA）的亚细胞分布。使用间接免疫细胞化学方法，用针对 PHA 或菜豆球蛋白的兔抗体对超微冷冻切片进行免疫标记，从而对这些蛋白进行定位。然后，使用吸附在 4 至 5nm 胶体金颗粒上的抗兔免疫球蛋白 G 对结合的抗体进行定位。将切片用 OsO4 后固定，然后进行脱水，并在网格上的塑料中进行包埋。PHA 和菜豆球蛋白在储存薄壁细胞中的分布相似，主要存在于正在发育的蛋白体中。内质网和高尔基体（顺面堆叠和相关小泡）也被这两种蛋白特异性标记，而细胞质和其他细胞器，如线粒体，则没有。我们将这些观察结果解释为支持这样一种假设，即储存蛋白和凝集素从其合成部位（粗面内质网）到其沉积部位（蛋白体）的运输是由高尔基体介导的。
