Variation in Hemicellulose Structure and Assembly in the Cell Wall Associated with the Transition from Earlywood to Latewood in Cryptomeria japonica.

The size of cellulose microfibril (CMF) bundles varies to interact with glucomannan/galactoglucomannan (GM/GGM). Arabino-4-O-methylglucuronoxylan (AGX) bonded CMF bundles coated with GM/GGM also have important roles in elaborating the distance between these components. Since the precise roles of GM/GGM and AGX are not clear, the elution analysis to evaluate the strength of the interaction between the cell wall were tried. Earlywood (EW) and latewood (LW) were separated in a Japanese cedar. The chemical components of cellulose, hemicellulose including GM/GGM and AGX, and lignin were almost the same in EW and LW. Slight differences in GM/GGM, the side-chain substitution in AGX and the ionic bond characteristics of glucuronic acid side chains were observed. Based on measurements of GM/GGM and AGX adhering to CMFs, there were more hemicelluloses forming strong hydrogen bonds in LW than in EW. The results showed that the highly assembled hemicellulose in LW produced a strong cell wall framework. [ABSTRACT FROM AUTHOR]