AVIs observed in transverse section of adaxial epidermal cells of inner petal region under light microscopy. A. Toluidine Blue stained cells, showing the AVIs have light dense inner structures (white arrowhead) and loose thread network (black arrowhead) around them in the central vacuole (V). Vesicle-like bodies (black arrow) are apparent both in the cytoplasm and in the central vacuole. Chloroplasts, black double arrowhead. B. I2-KI stained cells, showing AVI structure (white arrowhead) in the central vacuole (V) but many fewer threads revealed by this staining. Chloroplasts are indicated by double arrowhead.