Poster: Biotech Risk Assessment

Abs # 897: Genetic modification removes an immunodominant human allergen from soybean

Presenter:	Herman, Eliot M, eherman@danforthcenter.org
Authors	Herman, Eliot M (A)   Helm, Ricki  (B)   Jung, Rudolf  (C)   Kinney, Anthony  (D)
Affiliations:	(A): USDA-ARS, Danforth Plant Science Center (B): University of Arkansas for Medical Sciences (C): Pioneer Hi-Bred International (D): Dupont Experimental Station

The increasing use of soybean products in processed foods poses a potential threat to soybean-sensitive food-allergic individuals. In vitro assays on soybean seed proteins with sera from soybean-sensitive individuals have IgE reactivity to abundant storage proteins, and a few less-abundant seed proteins. One of these low abundance proteins, Gly m Bd 30 K, also referred to as P34, is in fact a major (i.e. immunodominant) soybean allergen. Although a member of the papain protease superfamily, Gly m Bd 30 K has a glycine in the conserved catalytic cysteine position found in all other cysteine proteases. Transgene-induced gene silencing was used to prevent the accumulation of Gly m Bd 30 K protein in soybean seeds. The Gly m Bd 30 K-silenced plants and their seeds lacked any compositional, developmental, structural or ultrastructural phenotypic differences when compared with control plants. Proteomic analysis of extracts from transgenic seed detected the suppression of Gly m Bd 30 K -related peptides but no other significant changes in polypeptide pattern. The lack of a collateral alteration of any other seed protein in the Gly m Bd 30 K silenced seeds supports the presumption that the protein does not have a role in seed protein processing and maturation. These data provide evidence for substantial equivalence of composition of transgenic and non-transgenic seed eliminating one of the dominant allergens of soybean seeds.