Binding of nascent glucuronoxylan to the cell walls of pea seedlings.

Glucuronoxylan synthesised in vitro by membrane-bound enzymes from etiolated pea epicotyls was found to bind to isolated cell walls from the same tissue in a pH-dependant manner. The binding was maximum at pH 3.5-4.0, and decreased to zero at pH 6. The bound glucuronoxylan could be dissociated from the cell walls by washing at pH 6, and the binding appeared to be non-covalent. Extraction experiments indicated that the glucuronoxylan was binding to hemicellulose in the cell-wall. The observed binding may be significant in the process of cell-wall assembly in vivo.