Seasonal and within-stem variations of neutral lipids in silver birch (Betula pendula) wood.

Neutral lipids were analyzed in stem wood of a 7-year-old clone and in five 35-70-year-old mature trees of silver birch (Betula pendula Roth). In young trees and in mature wood of old trees, the free fatty acid fraction comprised less than 5% of the concentration of triacylglycerols (TG). The concentration of free linoleic acid was lowest in March when the young trees were dormant and highest during midsummer and September. In mature trees, the TG concentration increased toward the pith, indicating that living parenchyma cells close to the pith have a large TG storage capacity. The TG concentration (mean 0.51 +/- 0.02% of wood dry mass) remained constant throughout the year in young trees, whereas the concentration of beta-sitosterol, the dominant free sterol (mean 82.5 +/- 0.4% of total free sterols), decreased during spring and early summer when the temperature gradually increased, and increased during autumn when the trees became dormant. In young trees, we detected a seasonal interconversion between the free and esterified forms of beta-sitosterol and campesterol, and within the steryl ester fraction between squalene and betulaprenol-7. The concentration of esterified sterols/isoprenoids was exceptionally high, especially in the inner regions of mature stem wood (mean 0.6 +/- 0.03% of wood dry mass). No heartwood formation was detected.

[1]  H. Ziegler,et al.  Lipids and lipolytic enzymes in the trunkwood ofRobinia pseudoacacia L. during heartwood formation , 1996, Trees.

[2]  Jörg J. Sauter,et al.  Storage, mobilization and interrelations of starch, sugars, protein and fat in the ray storage tissue of poplar trees , 1994, Trees.

[3]  P. Saranpää,et al.  Variation in the amount of triacylglycerols and steryl esters in the outer sapwood of Pinus sylvestris L. , 1994, Trees.

[4]  C. Fischer,et al.  Food reserves of scots pine (Pinus sylvestris L.) , 1992, Trees.

[5]  W. Höll,et al.  Food reserves of Scots pine (Pinus sylvestris L.) , 1991, Trees.

[6]  P. Saranpää,et al.  Seasonal variation of neutral lipids in Pinus sylvestris L. sapwood and heartwood , 1987, Trees.

[7]  W. Höll,et al.  Concentration gradients of free sterols, steryl esters and lipid phosphorus in the trunkwood of Scot's pine (Pinus sylvestris L.) , 1987, Trees.

[8]  P. Saranpää,et al.  Lipids and sterols of Pinus sylvestris L. sapwood and heartwood , 1987, Trees.

[9]  Andreas Richter,et al.  Non‐structural carbon compounds in temperate forest trees , 2003 .

[10]  S. Clouse.  Arabidopsis Mutants Reveal Multiple Roles for Sterols in Plant Development , 2002, The Plant Cell Online.

[11]  D. Delmer,et al.  Sitosterol-β-glucoside as Primer for Cellulose Synthesis in Plants , 2002, Science.

[12]  P. Saranpää,et al.  Variation of non-structural carbohydrates in silver birch (Betula pendula Roth) wood , 2001, Trees.

[13]  S. Clouse,et al.  BRASSINOSTEROIDS: Essential Regulators of Plant Growth and Development. , 1998, Annual review of plant physiology and plant molecular biology.

[14]  M. Hartmann.  Plant sterols and the membrane environment , 1998 .

[15]  G. Spiteller,et al.  Oxidized phytosterols increase by ageing in photoautotrophic cell cultures of Chenopodium rubrum , 1997 .

[16]  M. Hartmann,et al.  Sterol Modulation of the Plasma Membrane H+-ATPase Activity from Corn Roots Reconstituted into Soybean Lipids , 1997, Plant physiology.

[17]  A. Rahier,et al.  Fungicides as Tools in Studying Postsqualene Sterol Synthesis in Plants , 1997 .

[18]  C. Breuil,et al.  Using solid-phase extraction to assess why aspen causes more pitch problems than softwoods in kraft pulping , 1995 .

[19]  R. Bronner,et al.  Regulation of Sterol Content in Membranes by Subcellular Compartmentation of Steryl-Esters Accumulating in a Sterol-Overproducing Tobacco Mutant , 1994, Plant physiology.

[20]  J. Palta,et al.  Plasma Membrane Lipids Associated with Genetic Variability in Freezing Tolerance and Cold Acclimation of Solanum Species , 1993, Plant physiology.

[21]  L. Goad,et al.  Steryl fatty acyl esters in plants , 1993 .

[22]  Z. Wojciechowski.  Biochemistry of Phytosterol Conjugates , 1992 .

[23]  G. Patterson.  Physiology and Biochemistry of Sterols , 1992 .

[24]  Ute Harms,et al.  Changes in Content of Starch, Protein, Fat and Sugars in the Branchwood of Betula pendula Roth during Fall , 1992 .

[25]  Jörg J. Sauter,et al.  Biochemical and Ultrastructural Results during Starch-Sugar-Conversion in Ray Parenchyma Cells of Populus during Cold Adaptation , 1991 .

[26]  D. V. Lynch,et al.  Plasma Membrane Lipid Alterations Associated with Cold Acclimation of Winter Rye Seedlings (Secale cereale L. cv Puma). , 1987, Plant physiology.

[27]  L. W. Parks,et al.  Multiple functions for sterols in Saccharomyces cerevisiae. , 1985, Biochimica et biophysica acta.

[28]  W. Höll,et al.  Storage Lipids in the Trunk- and Rootwood of Tilia cordata Mill. from the Dormant to the Growing Period , 1985 .

[29]  W Hou,et al.  Seasonal Fluctuation of Reserve Materials in the Trunkwood of Spruce [Picea abies (L.) Karst]. , 1985, Journal of plant physiology.

[30]  M. Uemura,et al.  Involvement of Plasma Membrane Alterations in Cold Acclimation of Winter Rye Seedlings (Secale cereale L. cv Puma). , 1984, Plant physiology.

[31]  H. Nyberg,et al.  The phospholipid fatty acids of Porphyridium purpureum cultured in the presence of triton x-100 and sodium desoxycholate , 1984 .

[32]  J. G. Roddick,et al.  Annual Variation in Sterol Levels in Leaves of Taraxacum officinale Weber. , 1981, Plant physiology.

[33]  W. Höll.  Lipase Activity in the Trunkwood of Tilia cor dataMill. , 1975 .

[34]  W. Höll,et al.  Radial Distribution and Partial Characterization of Lipids in the Trunk of Three Hardwoods , 1975 .

[35]  D. L. Davis,et al.  Influence of Temperature on Sterol Biosynthesis in Triticum aestivum. , 1973, Plant physiology.

[36]  R. Wright.  A reagent for the non-destructive location of steroids and some other lipophilic materials on silica gel thin-layer chromatograms. , 1971, Journal of chromatography.

[37]  E. Work,et al.  Laboratory techniques in biochemistry and molecular biology , 1969 .

[38]  A. Assarsson,et al.  Studies on wood resin, especially the change in chemical composition during seasoning of the wood. Part 4. The composition of the petroleum ether soluble nonvolatile extractives from fresh Spruce, Pine, Birch and Aspen wood , 1966 .

[39]  M. Zimmermann,et al.  The formation of wood in forest trees. , 1964 .

[40]  H. Ziegler,et al.  Storage, Mobilization and Distribution of Reserve Material in Trees , 1964 .

[41]  I. Croon,et al.  Studies on wood resin, especially the change in chemical composition during seasoning of the wood. Part 1. Changes in the composition of the ethyl ether soluble part of the extractives from Birch wood during log seasoning , 1963 .

[42]  L. Clermont.  The fatty acids of Aspen Poplar, Basswood, Yellow Birch and White Birch , 1961 .

[43]  L. Selleby.  Birch wood constituents. Part 2. The ether extract. , 1960 .

[44]  E. W. Sinnott.  Factors Determining Character and Distribution of Food Reserve in Woody Plants , 1918, Botanical Gazette.