Studies on “Bluing Effect” in the Petals of Red Rose VI

Further observations on the development of blue color of the spherule

抄録

Electron-microscopical, histochemical and histophotometrical studies were given to the blue spherule present in the upper epidermal cells of rose petals exhibiting the bluing effect. The reults obtained are summarized below.
1. The observation with electron-microscope clearly demonstrated that three layers are distinguishable in the spherule, and that the parietal cytoplasmic layer which is lying along the cell wall takes the direction to the surface of the spherule running around it at the portion where the spherule is quite near to the cell wall.
2. When the intact spherules were treated with citric acid, EDTA and o-phenanthroline in the pH 3, 4 or 7, they retained the original blue color, but their blue color turned red by the reagents in pH 2 and 0.1 N hydrochloric acid (pH 1).
3. After the treatments of these reagents, iron was detected in the spherules showing blue color, but not in the spherule colored in red.
4. The complex staining of cyanin and ferric sulphate were given to the spherules decolored with 1% methanolic hydrochloric acid. The same staining features were obtained both in the Treatment 1 (decolored spherule→stained with cyanin→stained with ferric sulphate) and in the Treatment 2 (decolored spherule→stained with ferric sulphate→stained with cyanin.)
5. The absorption curves of the epidermal cells containing the blue spherule showed rather wide range of absorption from 470-680nm.
6. The relationship among anthocyanin, iron and the surface of the spherule is discussed.