Engineering Flax Plants To Increase Their Antioxidant Capacity and Improve Oil Composition and Stability

Abstract

The composition of polyunsaturated fatty acids in the tissues is very important to human health and strongly depends on dietary intake. Since flax seeds are the richest source of polyunsaturated acids, their consumption might be beneficial for human health. Unfortunately, they are highly susceptible to auto-oxidation, which generates toxic derivatives. The main goal of this study was the generation of genetically modified flax plants with increased antioxidant potential and stable and healthy oil production. Since among phenylpropanoid compounds those belonging to the flavonoid route have the lowest antioxidant capacity, the approach was to inhibit this route of the pathway, which might result in accumulation of other compounds more effective in antioxidation. The suppression of the chalcone synthase gene resulted in hydrolyzable tannin accumulation and thus increased antioxidant status of seeds of the transgenic plant. This was due to the partial redirecting of substrates for flavonoid biosynthesis to the other routes of the phenylpropanoid pathway. Consequently, transgenic plants produced more (20-45%) polyunsaturated fatty acids than the control and mainly α-linolenic acid. Thus, increasing the antioxidant potential of flax plants has benefits in terms of the yield of suitable oil for human dietary consumption.

Linseed, the multipurpose plant

“…All these compounds are regarded as strong antioxidants, and thus it is suggested that they might be involved in protection of fatty acids against oxidation during seed storage and industrial oil extraction. Indeed, engineered linseed plants accumulating phenylpropanoids (mainly hydrolysable tannins) produces oil with a significantly increased quantity (5-fold) of omega-3 fatty acids in comparison to control plants (Zuk et al, 2012). Thus, the obtained results strongly suggest that fatty acid composition and yield depend on the antioxidative status of seeds.…”

Biotechnology of fibrous flax in Europe and China

“…This was conducted by down-regulation of the chalcone synthase (CS) gene and redirecting the substrates from the flavonoids into tannin synthesis, phenylpropanoids with higher antioxidant properties (Zuk et al, 2012). This paper is particularly concerned with fiber improvement.…”

“…The one example is flax type (called W86) overaccumulating tannins, producing oil with "ideal characteristic" which includes suitable ratio of 6/3 fatty acids recommended by FDA, the presence of tocopherols and water soluble antioxidants which guarantee oil stability (Zuk et al, 2012). Another example is the flax type (called W92) overproducing phenolics whose fibers were successfully used for preparing wound dressing for chronic wound healing (Skórkowska-Telichowska et al, 2011).…”

“…Another example is the flax type (called W92) overproducing phenolics whose fibers were successfully used for preparing wound dressing for chronic wound healing (Skórkowska-Telichowska et al, 2011). Also another already mentioned new flax types obtained by genetic engineering were described were described, like flax producing PHB, flax with lower lignin or pectin level, flax with changed polysaccharide composition (Czemplik et al, 2012;Day et al, 2009;Lorenc-Kukuła et al, 2005Musialak et al, 2008;Roach et al, 2011;Wrobel-Kwiatkowska et al, 2004;Wróbel-Kwiatkowska et al, 2007a;Wróbel et al, 2004;Zuk et al, 2012).…”

Transgenic flax/linseed (Linum usitatissimum L.) - expectations and reality

“…Abbadi et al (2004) reported a high accumulation of 20C PUFAs including ARA and EPA in transgenic flaxseed after transformation with genes encoding acyl-desaturases and acyl-elongases from Physcomitrella patens, Borago officinalis and Phaeodactylum. Zuk et al (2012) observed significantly increased PUFA levels in plants transformed with a chalcone synthase gene from Petunia hybrida. Polyakov et al (1998) transformed fibre flax cultivars and analysed the expression of introduced genes coding NPT II and GUS.…”