THE BIOSYNTHESIS OF CELL WALL CARBOHYDRATES: IV. FURTHER STUDIES ON CELLULOSE AND XYLAN IN WHEAT

Abstract

D-Glucose-1-C14, D-glucose-6-C14, D-mannose-1-C14, D-galactose-1-C14, D-glucuronolactone-1-C14, D-glucuronolactone-6-C14, potassium D-gluconate-6-C14, and L-arabinose-1-C14 were administered to wheat shoots. The cellulose and xylan were isolated after a 5 hour period of metabolism. Glucose was more readily converted to cellulose and xylan than any of the other compounds tested. The distribution of C14 in the glucose and xylose isolated from the polysaccharides indicates that xylan was formed from the aldohexoses and glucuronolactone by processes involving loss of carbon-6. L-Arabinose, unlike D-xylose and D-ribose, was converted to xylan with little rearrangement of the pentose skeleton.