The observation of root in the Arnebia euchroma with microstructure and submicrosturcture

we found that the naphthoquinone pigment occurrd mainly in the cytoplasm of phellem cells

had a shape of oil globule

and had not ben bundled by membrane. An enzyme relating to spothesls of pigment distributed probably in tht plasma membrane or endoplasmlc retlculum membrane surroundd It. This membrane provldes a place for synthesis of the pigment. Phellem of cells could promote the formation of the naphthoquinone pigment.