Gold-labeling in the leaves. Arrows indicate gold particles. (A) Gold-labeling in a vacuole of an epidermal cell. (B) Gold-labeling in the protoplasm of a meristem cell. (C) Gold particles in the vacuole of a meristem cell. (D) Gold-labeling in the protoplasm of a palisade parenchymal cell. (E) Magnified view of D. (F) Gold particles in the vacuole of a spongy parenchymal cell. (G) Control section wherein SSd was removed. (H) Control section incubated without colloidal gold–labeled SSd antibodies. Scale bars: A, C, D =100 nm; B, E, F = 50 nm; G = 500 nm; H = 200 nm.