Reduction in Phytic Acid Content of Maize and Soybean by Gene Suppression

A group of scientists from DuPont recently derived soybean and maize with reduced phytic acid content by embryo-specific gene suppression. Phytic acid, a chemical largely contained in cereal grains and oilseeds, has a negative impact on animal nutrition and the environment. Since phosphorus normally binds to phytic acid, it is being added to the otherwise phosphorus rich cereal grains. It is poorly digested by many animals and in the digestive tract, phytic acid is known to form complexes with certain enzymes and proteins resulting to decreased amino acid availability and digestive enzyme inactivity. Accordingly, it decreases the bioavailability of certain essential minerals like iron, zinc and calcium. The undigested phytic acid excreted in animal wastes is considered as the leading source of phosphorus pollution from agriculture.  

The gene coding for a transporter protein associated with multidrug resistance, previously found to be defective in low phytic acid  mutants, was specifically targeted for silencing. The low phytic acid maize derived by gene suppression shows no undesirable agronomic properties. In addition, seeds with reduced phytic acid were obtained by silencing a soybean gene homologous to that of maize, suggesting that their strategy might be applicable to other crops.

The article was published in the journal Nature Biotechnology and can be accessed by subscribers at http://www.nature.com/nbt/journal/v25/n8/full/nbt1322.html