A xyloglucan in etiolated seedlings of Pinus radiata

The changes in cell wall carbohydrates and starch were investigated in hypocotyls and cotyledons during growth of etiolated seedlings of Pinus radiata. Starch was depleted within two weeks with an accompanying: rise in a hemicellulosic xyloglucan component. This was purified by fractional precipitation. Fractionation, methylation analysis, partial hydrolysis and chromium trioxide oxidation showed that this component was a fucogalactoxyloglucan of similar structure to those reported from dicots. It was the major hemicellulose in two-week-old hypocotyls and cotyledons. Other cell wall polysaccharides for which evidence was obtained by methylation analysis were a xylan, a glucomannan and an arabinan. (C) 1997 Elsevier Science Ltd.