Searching for a soybean absent the P34 protein that provokes allergic reactions in 6 to 8% of children is like looking for a needle in a haystack, but the "needle" has been found.
"After screening over 11,000 plant types from the USDA germplasm collection in Urbana, one confirmed P34 null line and approximately 91 lines with significantly reduced levels of P34 have been found," says lead researcher Ted Hymowitz, a plant geneticist at the University of Illinois at Urbana-Champaign.
Roughly 5,000 more plant types are to be tested, but the fact that one without the P34 protein has been found is encouraging, researchers say.
Because baby formulas utilize soy, a hypoallergenic soybean would help reduce the number of infants suffering allergic responses. An allergic response might include hives, itching, diarrhea and, in rare cases, anaphylactic shock.
"The process we're using is looking for naturally occurring variants so there's no question about the safety of it," Hymowitz says. "We're providing an alternate approach to genetically engineering for a P34 null line."
Although a P34-free soybean could be produced using biotechnology, concerns about employing transgenic ingredients in baby food might worry people. "While there is no cause for concern in using biotechnology in baby food, people do worry and may not buy it," Hymowitz says.
After all the plant types have been tested, the next step will be transferring the P34-suppressing trait into a high-yielding, disease-resistant soybean cultivar. The first soybeans tested were those currently grown commercially, which all contain P34.
Eliminating P34 doesn't impact a soybean's nutritional content, Hymowitz notes. However, the testing process is slow. Only 100 plant types can be tested daily.
"We're doing the qualitative analysis. Does it have the protein or doesn't it? It's a dominant protein, so it's rare to find ones that don't have it," says Hymowitz. "The ones we find with little or no P34 are sent to (co-lead researcher) Eliot Herman's USDA lab at the Donald Danforth Plant Science Center in St. Louis, Mo. They do the quantitative analysis."
A molecular biologist with USDA's Agricultural Research Service, Herman is adjunct professor of Plant Science at the University of Missouri.
Project co-investigator Leina Mary Joseph of the University of Illinois is in charge of testing the seeds using immunological procedures.
"The Danforth lab uses a different technique to confirm that the result we got is accurate," Joseph says. "We found a null that doesn't have any of the P34 protein and it has been confirmed by their lab. We are already growing some of the null and low-P34-protein lines in the greenhouse so we'll have a good supply of seeds when we need them."
The Illinois-Missouri Biotechnology Alliance, with a special grant from USDA, provides the project funding.