TOTAL HEMICELLULOSES FROM OAT PLANTS AT DIFFERENT STAGES OF GROWTH

Total hemicelluloses have been isolated from the leaves and stems of field-grown oat plants and from the leaves, roots and coleoptiles of plants grown in the laboratory. In any one part of the plant, with increasing maturity there is an increase in the percentage of xylose and a decrease in the percentage of glucose residues. These changes and accompanying changes in the percentages of galactose and arabinose residues are considered in terms of three pure hemicelluloses known to be present-an arabinoxylan, an acidic galactoarabinoxylan and a non-cellulosic glucan. Pure galactoarabinoxylans were isolated from the leaves of field-grown oat plants at different stages of growth. The results indicate that it is inappropriate to study the effect of growth on hemicellulosic composition solely by considering pure hemicelluloses. © 1970.