Using biotechnology, researchers shut off the gene for a crucial protein that makes soybean seeds so allergenic to some consumers.

The advance – by scientists with the Agricultural Research Service, University of Arkansas (UA), and private industry – could shorten the list of products that soy-sensitive consumers often must avoid eating. Worldwide, 6-8% of children and 1-2% of adults suffer food allergies. Soybeans, milk, eggs, peanuts, tree nuts, fish, wheat and shellfish cause 90-plus percent of food allergic reactions, primarily in children.

More than half of all soy allergies are caused by a protein called P34. Now, however, Eliot Herman, Rick Helm and collaborators have developed strains of soybean plants whose seed cannot make this allergenic protein. They resorted to a biotech method called "gene silencing," rather than conventional plant breeding, because P34 is so widespread among both wild and cultivated soybeans.

Herman, an ARS plant physiologist at the Donald Danforth Plant Science Center in St. Louis, MO, believes this marks the first time a dominant human allergen has been eliminated from a major food crop by this method. Field trials begun in 2001 indicate the modified beans' agronomic properties are no different than those of unaltered plants whose seed contains P34, Herman reports. Testing continues, though, to further verify their diminished allergenicity (or "hypoallergenicity") and commercial potential.

For example, this summer the researchers began feeding the hypoallergenic beans to newborn piglets to compare the animals' reactions to those fed unaltered beans. The study, which includes skin-prick allergenicity tests, is being led by Helm, an immunologist at the UA-Arkansas Children's Hospital Research Institute in Little Rock.

Eventually, this study and others could serve as a springboard to clinical trials with humans and set the stage for commercial cultivars that could benefit many food products, including flour, cereals and baby formulas.