Distribution and Seasonal Variation of Polyamines in Shootaxes of Spruce ( Picea abies (L.) KARST.)

Abstract

The distribution of free putrescine and free spermidine within 2-year-old and 6- to 7-year-old shoot-axes of Picea abies (L.) Karst. was determined on several dates during the growing season. Putrescine was the major amine in all tissue fractions investigated. The highest putrescine contents occurred in the meristematic cell layer of the cambial region during pronounced cambial activity. At the onset of latewood production, cambial putrescine levels declined sharply and thereafter remained more or less constant until fall. In the cortex, putrescine concentrations were in general significantly lower than in the cambial zone and exhibited less marked seasonal variation. The polyamine amounts measured in the wood were very small and nearly constant throughout the vegetation period. The possible significance of the predominant occurrence of polyamines in the cambial region of spruce stems is discussed with regard to cambial growth and developmental processes.