Genetic modification (GM) of wheat genes to ‘silence’ protein fractions toxic to those with celiac disease holds promise for cereal development, researchers say.
The review, published in the Journal of Cereal Science, suggested that while conventional breeding approaches to obtain wheat strains with reduced gluten toxicity was difficult, using GM technology presented an “attractive opportunity”.
RNA interference (RNAi) technology held the greatest promise in reducing or ‘silencing’ the gluten proteins in wheat and other cereals, they said. Via the technology, the gluten fractions toxic to those with celiac disease could be adjusted, enabling the development of gluten-free cereal grains.
Overcoming GM reserve
However, they said progression could face hurdles given global concerns around GM.
“Until now, most commercialized GM crops offer pest of herbicide resistance, for which the end consumer benefits are not obvious. For consumers, large companies and/or farmers, are the major beneficiaries of GM crops, and the benefits that they may have for agriculture and the environment is very diluted as a result of heavy campaigning by anti-GMO groups in developed countries,” they researchers wrote.
However, they said the development of GM wheat lines suitable for celiacs and other gluten intolerances could be a major turning point. “It aims to solve a health problem that directly affects a large proportion of consumers, in developed as well as developing countries, and with higher consumer awareness.”
RNAi technology: Impacts on baking?
The researchers said that in some instances the protein fraction gliadin in wheat had been reduced by as much as 16% using RNAi. In barley, C-hordeins (the sulphur-poor storage proteins of barley, similar to u-gliadins featuring in wheat) had been reduced by as much as 40%.
“Several groups have taken advantage of the possibilities that the RNAi technology offers for the silencing of multigene families, and have also addressed the down-regulation of more than one group of gliadins and/or glutenins,” they wrote.
However, the researchers warned of the need to consider the impact on baking quality when using RNAi technology and whether minimizing the gluten fractions translated to effective reduction in the end foodstuff.
Although, they added that research so far into reducing a-gliadins in wheat indicated strong differences between wild wheat flour and engineered strains, but found that rheological properties of the doughs were “almost identical” and baking performance was unchanged.
The researchers said that considering how gluten had attracted increased attention in recent decades due to the increasing number of diagnosed patients with intolerance and improved detection methods, progress into GM strains was extremely relevant.
Source: Journal of Cereal Science
Published online ahead of print, doi: 10.1016.j.jcs.2013.10.001
“Cereals for developing gluten-free products and analytical tools for gluten detection”
Authors: CM. Rosell, F. Barro, C. Sousa, MC. Mena