Characteristics of High α‐Linolenic Acid Accumulation in Seed Oils

Abstract

Modern diets are often deficient in omega-3 fatty acids and additional dietary sources of omega-3 fatty acids are useful. In order to investigate the molecular basis of the high accumulation of the omega-3 fatty acid, alpha-linolenic acid (18:3), in three different plants, flax (Linum usitatissimum), Dracocephalum moldavica, and Perilla frutescens omega-3 desaturase activity, transcript levels, and 18:3 in-vivo synthesis were examined. The 18:3 content was found to be higher at the later developmental stage of D. moldavica (68%) compared with P. frutescens (59%) and flax (45%) cotyledons. The 18:3 and 18:2 contents in both PC and TAG were determined during various stages of seed development for all three plants in addition to soybean (Glycine max). Northern blot analysis data of three different stages of D. moldavica, flax, and P. frutescens compared with moderately low 18:3 producers, soybean (Glycine max), and Arabidopsis thaliana and Brassica napus, (8-10% 18:3) at a stage of zygotic embryo development of high triglyceride synthesis showed that omega-3 desaturase mRNA levels were higher in all three high 18:3 producers, flax, D. moldavica and P. frutescens. This indicates that the high level of alpha-linolenic acid in TAG may be largely controlled by the level of omega-3 desaturase gene expression. However, the PC versus TAG fatty acid composition data suggested that along with omega-3 desaturase other enzymes also play a role in 18:3 accumulation in TAG, and the high accumulators have a selective transfer of alpha-linolenic acid into TAG.

Association mapping of seed quality traits using the Canadian flax (Linum usitatissimum L.) core collection

“…Seed oils are composed primarily of triacylglycerols (TAGs), which are glycerol esters of FAs (Rao et al 2008). The primary FAs in the TAGs of oilseed crops are 16–18 carbons in length and contain 0–3 double bonds where PAL, STE, OLE, LIO and LIN predominate (Rao et al 2008).…”

Identification of a Pair of Phospholipid:Diacylglycerol Acyltransferases from Developing Flax (Linum usitatissimum L.) Seed Catalyzing the Selective Production of Trilinolenin

“…Ethyl methanesulfonate-generated point mutations in LuFAD3A and LuFAD3B led to a reduction in ALA content to ϳ1-2%, suggesting that these two genes encoded the main desaturases responsible for the synthesis of ALA in flax (4 -6). Generally, there is good correlation between the expression of FAD3 genes with the accumulation of ALA in flax and other plant species (7). However, along with desaturases, many other enzymes can contribute to the flux of ALA to storage lipids.…”

Olive oil assessment in edible oil blends by means of ATR-FTIR and chemometrics

“…3A) with very high positive scores in both PC1 and especially in PC2. Flaxseed oil is a drying oil with a very high content in polyunsaturated fatty acids, particularly linolenic acid, which explains the difference with the rest of the oils (Rao, Abdel-Reheem, Bhella, McCracken, & Hildebrand, 2008). Looking at the loading of the PC2 the most intense contribution is the band at 2956 cm À1 .…”