Dynamics of desaturase gene expression in the process of oil flax seed formation

   Oil flax (Linum usitatissimum L.) is a multi-purpose crop used in many industries. The composition of traditional flax seed oil varieties is characterized by a high content of desaturated Omega-3 fatty acids. In the process of lipid biosynthesis in the cell, an important step is the desaturation of fatty acids, which determines the final ratio of saturated and desaturated fatty acids in the oil. The main enzymes that determine the efficiency of desaturation are membrane-bound desaturases (FADs) and soluble desaturases (SADs).

   The purpose of the work is to study the expression of desaturase genes in the process of seed development of different oilseed flax varieties.

   Eight varieties of oil flax with different fatty acid composition of oil served as the material for the study. The samples were grown in a plant chamber until flowering and on days 5, 10, 15, 20, 25, 30 and 35 after flowering, bolls were taken from the plants followed by RNA extraction from the seeds. Then reverse transcription and semi-quantitative RT-PCR were performed. The resulting reaction products were separated using a 1.2 % agarose gel. The adenine phosphoribosyltransferase-1 (APT1) gene was used as a reference. As a result of the study, data were obtained on the expression of six flax desaturase genes: SAD1, SAD2, FAD2A, FAD2B, FAD3A and FAD3B. Evaluation of the expression of the SAD1 and SAD2 genes in all the studied varieties at all the studied stages of seed development did not find any differences. Expression of desaturase genes of the FAD2 family depended on the stage of seed development. During the studied period of seed formation, the expression level was high, indicating the intensity of biosynthesis and accumulation of α-linolenic and linoleic acids. The expression of FAD3 desaturase genes, which control the final stage of the conversion of flax desaturated fatty acids, did not significantly depend on the time after flowering. A proportional dependence of the content of α-linolenic acid in oil on the level of expression of the FAD3 desaturase genes was revealed. The data obtained indicate the dynamics in the metabolism of fatty acids during the formation of flax seeds. Genotype specificity was determined when assessing the expression of desaturases of the FAD family in oil flax seeds.

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