Optical Microscopy and Scanning Electron Microscopy on the Surface of Rice Callus after Treatment with Cell Wall Degrading Enzymes

Two distinctive structures were observed on the surface of rice callus treated with cell wall degrading enzymes, pectinase and cellulase by scanning electron microscopy; i.e., membranous, and the fibrillar structures. The membranous layer was digestible with the enzymes, while the fibrillar structures were not. The membranous matrix was mucilaginous, and positive to PAS reaction. Protoplasts were released after the enzyme treatment from the areas covered with the enzyme-digestible mucilaginous layer. The role of the extracellular matrix of the rice callus is discussed from the standpoint of growth and differentiation of the rice callus.