Flax and Linseed - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 246

Linum was among the first crop species to benefit from a herbicide resistant
construct, as glyphosate (Roundup) resistance. Sulfonylurea and glufosinate resis-
tance all were quickly introduced and field tested in commercial linseed flax
genotypes. Flax has been transformed with the aim to improve resistance to
Fusarium [ 134 ]. The idea was that the increase in the flavonoid content in trans-
genic flax plants might be the reason for observed, enhanced antioxidant capacity of
those plants. The increased antioxidative properties of transgenic plants may lead to
improve resistance to Fusarium . Successful transformation of L. usitatissimum
plants with bacterial genes involved in polyhydroxybutyrate synthesis has also
been reported [ 135 ]. This offers new perspectives for environmentally safe produc-
tion of basic components for modern biodegradable composites. Flax as an indus-
trial crop can be utilized for phytoremediation as well. Flax transformation with
heavy metal-binding proteins has been reported [ 136 ]. However, to date, no trans-
genic linseed/flax is permitted to grow for commercial utilization. Only one trans-
genic linseed has reached registered cultivar status, “CDC Triffid,” but
authorization of the variety was rescinded in Canada in 2001 and commercial
cultivation of CDC Triffid flax has since been banned.
GM flax is being developed primarily for agronomic traits. Herbicide tolerance
is very important for weed control, as well as fungal resistance, insect resistance,
and stress tolerance to adapt to changing climate and local factors. In addition,
quality traits of flax that are of interest include modified oil composition in
particular enrichment for health-promoting ingredients, such as flavonoids (antiox-
idants) and omega-3 fatty acids. The shift to renewable resources also influenced
the development of flax with modified fiber composition (modified elasticity and
thermoplastic characteristics of the flaxseed fiber for the synthesis of biological
degradable synthetic material), production of pharmaceutical agents (molecular
pharming usage of GM flaxseed as a system to produce pharmaceuticals, which
to date is only experimental), and land reclamation (specifically phytoremediation
of heavy metal-contaminated soil where the plants are modified so they are able to
grow within this soil and extract heavy metals and accumulate them within the plant
biomass) [ 136 - 138 ].
Field trials of GM flaxseed have been conducted in the EU under three applica-
tions in three countries (Sweden, Poland, the Czech Republic) during 2005-2007.
The traits evaluated in these experiments were oil composition, flavonoid content,
elasticity (bioplastics), herbicide tolerance, insect resistance, insect and fungal
resistance, and heavy metal absorption. Also, there have been 198 applications
for transgenic field trials in Canada during 1988-2002, mostly for evaluating
herbicide tolerance.
No genetically modified flax is currently commercially available. A herbicide-
resistant GM flax was introduced in 2001, but was soon taken off the market
because European importers refused to buy it. In September 2009, it was reported
that Canadian flax exports had been contaminated by the unapproved, illegal,
genetically modified (GM) variety Triffid. Since linseed derived from GM flax
has not been authorized in Europe, products containing even minimal amounts
cannot be made commercially available. Transgene contamination of flaxseed has