CELL-WALL COMPOSITION AND ELASTICITY OF DORMANT AND GROWING WHITE SPRUCE (PICEA-GLAUCA) SEEDLINGS

White spruce [Picea glauca (Moench) Voss.] seedlings were used to stud y the changes in cell wall composition and elasticity in mature needle s before and after the resumption of growth following winter dormancy. Dormant seedlings showed high cell wall elasticity that decreased aft er the resumption of shoot growth. Cell wall hemicellulose content inc reased 3 days after planting and decreased after the buds flushed. Non -cellulosic glucose and arabinose were the sugars showing the most pro nounced changes related to shoot growth. Arabinose was the most abunda nt sugar residue in the pectin and hemicellulose fractions and it decr eased until day 10 after planting. At the same time, the levels of glu cose in pectin and hemicellulose increased. The results provide eviden ce for cell wall carbohydrate turnover in dormant and active seedlings before and after bud flushing.