Genetic Engineering to Increase Crops' Essential Amino Acid Content

Amino acids play central roles as building blocks of proteins and as intermediates in metabolism. Humans and many farm animals cannot synthesize certain amino acids. In humans, failure to obtain even one of these essential amino acids results to degradation of the body’s protein to obtain the one amino acid that is needed. Scientists have successfully used genetic engineering to enrich the amino acid contents of crop plants. Lysine, methionine and tryptophan have received the most attention since they are typically limiting in cereals and legumes. A review paper published in the journal Plant Physiology summarizes the recent developments in the use of genetic engineering to produce amino acid fortified crops.

Numerous researches have demonstrated the potential to increase the contents of tryptophan and methionine in a seed-specific manner. A high-lysine maize cultivar, LY038, represents the first genetically modified (GM) crop with high nutritional value to be approved for commercial use in a number of countries. High methionine lupin varieties have also been proven beneficial in feeding trials.

Shai Ufaz and Gad Galili, authors of the paper, noted that the opportunities for and the impacts of GM crops with improved amino acid contents depend on public acceptance. Despite the fact that the LY038 maize was approved for commercial use in a number of countries, for instance, there remains a public debate about its safety.

The open access article is available at http://www.plantphysiol.org/cgi/content/full/147/3/954