Gold-labeling in the stems. Arrows indicate the gold particles. (A) Gold particles were detected in the vacuoles of ground meristem cells in the shoot apex. (B) Magnified view of a vacuole in a cortex cell showing the gold-labeling. (C) Magnified view of the protoplasm of a cortex cell showing some gold particles. (D) Gold particles in the protoplasm of a phloem companion cell. (E) Gold particles in the vacuole of a secretory epithelial cell in the cortex. (F) Immunogold localization in the vacuole of a cambium cell. (G) Immunogold localization in the ER of a xylem parenchymal cell. Bar = 200 nm. (H) Magnified view of G. Scale bars: A–D, F, H = 50 nm; E = 100 nm; G = 200 nm.