Neutral lipids and phospholipids in Scots pine (Pinus sylvestris) sapwood and heartwood

• Published in: Tree Physiology
• Main Authors: Piispanen, R., Saranpää, P.
• Format: Text
• Language: English
• Published: Oxford University Press 2002
• Subjects: Original Articles; Northern Finland
• Online Access: http://treephys.oxfordjournals.org/cgi/content/short/22/9/661; https://doi.org/10.1093/treephys/22.9.661

Variations in the concentration and composition of triacylglycerols, free fatty acids and phospholipids were analyzed in Scots pine ( Pinus sylvestris L.) trees at five sites. Disks were taken at breast height or at a height of 4 m from the stems of 81 trees differing in diameter and growth rate. The mean concentration of triacylglycerols in sapwood was 26 mg g−1 dry mass; however, variation among trees was large (16–51 mg g dm −1). The concentration of triacylglycerols was slightly larger at 4 m height in the stem than at breast height. Concentrations of triacylglycerols did not differ between the sapwood of young and small-diameter stems (DBH < 12 cm) and the sapwood of old stems (DBH > 36 cm). Concentrations of free fatty acids were negligible in the outer sapwood, but ranged between 5 and 18 mg g dm −1 in the heartwood. The most abundant fatty acids of triacylglycerols were oleic (18:1), linoleic (18:2ω6, 18:2Δ5,9), linolenic (pinolenic, 18:3Δ5,9,12 and 18:3ω3) and eicosatrienoic acid (20:3Δ5,11,14 and 20:3ω6). The concentration of linoleic acid comprised 39–46% of the triacylglycerol fatty acids and the concentration was higher in the slow-growing stem from northern Finland than in the stems from southern Finland. Major phospholipids were detected only in sapwood, and only traces of lipid phosphorus were detected in heartwood.