Fatty Acid Composition of Lipids in Picea obovata Needles in the Spring Vegetation Period

Resumo

The dynamics of the fatty acid (FA) composition of total lipids in needles of Siberian spruce (Picea obovata L.) during the first half (March–July) of the 2010 vegetation season has been studied. Three maxima of the unsaturated fatty acid (UFA) content with increased levels of α-linolenic acid are revealed in the postwinter (March 10–April 6), spring (April 20–May 18), and summer (June 1–July 20) periods. During postwinter and spring vegetation, the UFA increase is accompanied by an increase in the oleic and linoleic desaturation ratios. The spring peak of the 18:3ω3 content coincides with the spring peak in chlorophylls in the light-harvesting complexes of photosynthetic units and with the onset of the net CO₂ assimilation. The summer peak is characterized by the level of chlorophylls, which is the highest over the entire monitoring period. The possible ways that the FA is involved in the rearrangement of the structural and functional organization of the photosynthetic apparatus of a coniferous plant are discussed.