Submitted to: The Plant Genome
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/30/2009
Publication Date: 7/10/2009
Citation: Bilyeu, K.D., Ren, C., Nguyen, H.T., Herman, E.M., Sleper, D.A. 2009. Association of a Four Basepair Insertion in the P34 Gene with the Low Allergen Trait in Soybean. The Plant Genome. 2(2):141-148. Interpretive Summary: Soybean is an important component of many foods and animal feeds. One limitation to the use of soybean is the presence of allergenic proteins in soybean seeds that elicit undesirable responses in humans and livestock that consume soybean products. The major soybean seed allergen is the protein P34, which has not been shown to be critical for normal seed development or composition. The objective of our research was to determine the molecular genetic basis for a low P34 allergen trait in two soybean germplasm accessions previously identified to accumulate reduced amounts of the allergenic P34 protein. We discovered a short sequence insertion in the P34 gene from the two low P34 soybean accessions that could account for the reduction in P34 protein accumulation. The discovery of this mutation enabled the development of molecular marker assays that will assist soybean breeders in developing soybean varieties with reduced allergens.
Technical Abstract: The value of soybean is determined in part by functionality of major seed components, extractable oil and high protein meal. Soybean meal is an important protein source for animal feeds, and use of soybean meal by the food industry is increasing. Food allergens have negative impacts for both foods and feeds. The major soybean allergen, Gly m Bd 30K, was identified as the P34 protein, a low abundance but highly conserved seed protein. Recently, two soybean germplasm accessions (PI 567476 and PI 603570 A) were identified as having reduced P34 content without other collateral changes in seed protein composition. In order to develop molecular markers to enhance breeding for low P34, our objective was to characterize the P34 gene region in wild-type and low P34 soybean lines and exploit any sequence differences to allow direct selection for mutant P34 alleles. The results indicated the two low P34 germplasm accessions contain a four basepair insertion at the P34 start codon. The mutant allele may inhibit efficient translation initiation of the P34 protein. Inheritance of the mutant P34 alleles completely associated with the low P34 phenotype. Molecular markers were developed that were based on the mutant allele of the P34 gene.