Cell wall biosynthesis: glycan containing oligomers in developing cotton fibers, cotton fabric, wood and paper

A series of oligomeric glycans can be extracted from the cell walls of deve loping cotton fibers with weak acid. Glycans that produce similar profiles on high pH anion chromatography with pulsed amperometric detection (HPAEC-P AD) are also found in a protein complex extracted from developing fibers an d in amorphous aggregates found in association with immature fibers in deve loping, but not in mature cotton bells. The quantity and composition of the glycans recovered from the carbohydrate-protein complex varies significant ly with the time of day when the bells are harvested. This diurnal variatio n is consistent with the hypothesis that secondary cell walls are deposited primarily at night. Incubation of re-hydrated cotton fibers in the presenc e of exogenous oligosaccharides, myo-inositol and glycerol substantially al ters the apparent quantity of the oligomers extracted from the fibers. The same and similar glycans have also been extracted from cotton fabric, marin e algae, various paper products and wood. While many of the oligomers isola ted from the various cellulose sources display the same peaks by HPAEC-PAD, the specific number of oligomers and their relative quantities appear uniq ue for each source of cellulosic material. Oligomeric glycans, as described in the preceding, are present in all cellulose sources that have been inve stigated. Their relative abundance changes in response to source, stage of development and other physiological variables. We hypothesize that the glyc ans are intermediates in the biological assembly of cellulose, and that the ir incorporation in cellulose is mediated by physicochemical and enzymatic mechanisms. (C) 2001 Elsevier Science Ltd. All rights reserved.