Figure 2

Radial sections of parenchyma cells in Pinus densiflora secondary phloem. (a) Radial section of broad argon ion beam milling (red-boxed area in Fig. 1a). Nuclei, protoplasmic 3D networks, and intracellular storage materials such as starch granules and oil bodies show good structural preservation without milling damage. The oil bodies exhibit a natural spherical shape, and vacuoles are void because epoxy resin embedding was not performed. (b) Radial microtome section. Starch granules were separated from the protoplasm by mechanical stress during the microtome cutting. The oil bodies were deformed by epoxy resin embedding, therefore presenting irregular shape, and the SEM image of the cell structure lost its depth information. N, nucleus; O, oil bodies; P, protoplasm; S, starch granules; V, vacuole. Scale bars = 20 µm.