Influence of water deficit on contents of carbohydrates and nitrogenous compounds in Pinus sylvestris L. and Larix sibirica Ledeb. tissues
2002
Sudachkova, N.E. (V.N.Sukachev Inst. of Forest, Krasnoyarsk (Russian F.)) | Milyutina I.L. | Semenova, G.P.
In order to study the physiological responses of Siberian conifers to water stress, the contents of total nitrogen protein, free amino acid, starch and content of low-molecular carbohydrates in needles, xylem and inner bark of stems and rough roots and the cellulose and lignin contents in stem and root xylem samples obtained from Pinus sylvestris L. (pine) and Larix sibirica Ledeb (larch). Trees in three habitats in Eastern Siberia with different amounts of annual precipitation were determined. Pine and larch trees originated from taiga populations had high growth rate of diameter and height increment by 30-40% compared with those from forest-steppe populations. Drought induced an accumulation of sugar due to an increase in monosaccharide concentration in tree tissues. Simultaneously, the content of non-protein forms of nitrogen rose. The tissues of current year shoots were used for identification of biochemical indices of water stress in pine and larch. The increase in the ratio of concentrations of low-molecular carbohydrates to protein nitrogen or the increase in ratio of total concentrations of arginine to the sum of concentrations of glutamic acid, proline and 4-aminobutyric acid in these tissues could be used as a marker of water stress. Water deficit does not have a significant effect on the contents of the main components of xylem - cellulose and lignin.
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