Fig. 1.
Low magnification view of a grazing section of a root hair cell between the nucleus and the apical dome of Vicia hirsuta. Vesicles packaged close to the cell wall are confined within an 'outline' similar to the endoplasmic reticulum (arrowheads point to an example) and continuous with it. Note the proximity of Golgi bodies. Examples of pyriform vesicles, which are electron dense, are circled; secretory vesicles are electron negative. The rectangular section at the top of the Figure is enlarged in Fig. 2. Note the excellent preservation of polyribosomes and mitochondrial ribosomes after freeze-substitution, and the coated vesicles in the area designated as possible trans-Golgi network. The cell wall and membrane are not stained. CW = cell wall, T = possible trans-Golgi network, A = amyloplast, D = dictyosome, M = mitochondrion. Bar = 500 nm.
Fig. 2.
High magnification view of the upper section rectangle of Fig. 1. Arrows indicate microtubules associated with a small vesicle 'package' close to the membrane. Bar = 200 nm.
Fig. 3.
High magnification view of grazing section to show dense packing of vesicles in a 'package' next to the plasma membrane. This section is consecutive to that shown as Fig. 1. Note the presence of numerous microtubules (arrows) within and close to the package, the mixture of secretory and pyriform vesicles, and the close proximity of a Golgi body (dictyosome). The plasma membrane and cell wall are unstained. CW = cell wall, D = dictyosome, T = trans-Golgi network. Bar = 200 nm.
Fig. 4.
High magnification view of a grazing section next to the plasma membrane showing micro-vesicles close to the plasma membrane and in association with macro-vesicles. Examples of micro-vesicles are indicated with circles, and microtubules with arrows. The size and shape of the micro-vesicles indicate that they are not transverse sections of the tails of pyriform vesicles. Note the dense packing of ribosomes in this section, indicating that there is a high level of mRNA translation, probably into nearby endoplasmic reticulum, and suggesting that this is an area active in protein movement through the endomembrane system. CW = cell wall, Me = plasma membrane. Bar = 200 nm.