Association of a Four-Basepair Insertion in the P34 Gene with the Low-Allergen Trait in Soybean

Abstract

The value of soybean [ (L.) Merr.] 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 603570A) 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.