Variation in the cellulose, lignin and silica contents of various parts of different rice (Oryza sativa L.) cultivars

Variation in and distribution of cell wall constituents such as cellulose, lignin and silica in the leaf blade, leaf sheaths and stems, and roots were investigated in 47 Indica and 6 japonica cultivars of rice (Oryza sativa L.). Cellulose, lignin, and silica were the most abundant components. Lignin and cellulose increased from the leaves to the roots, but silica decreased exponentially, with an almost insignificant amount found in the roots. The absorbed silica was mainly accumulated in the shoots, particularly in the leaf blade. A highly significant negative correlation was found between silica and lignin, and between silica and cellulose in the leaf blade. DMRT showed highly significant variations in the cell wall constituents among the cultivars. Cell wall modifications during biotic and abiotic stresses are also discussed. There is need for further research on the localization of cell wall constituents and the mechanism of cellulose and lignin contributing to tolerance.