The primary obstacles to the widespread acceptance of soy products lie in two key areas: allergens and an imbalanced amino acid profile found in soybean seeds. Thus, there is an urgent need for the development of new soybean cultivars that boast higher protein content, reduced allergenic properties, and increased levels of essential amino acids such as methionine and cysteine. The predominant culprits responsible for most allergenic reactions in soy protein are glycinins and ß-conglycinins, the most abundant seed proteins. In this project, we have introduced an innovative genome editing tool designed to modify the glycinin and ß-conglycinin genes. This approach allows us to produce proteins that not only contain elevated levels of methionine and cysteine but also exhibit reduced allergenicity. Our efforts involved the creation of two distinct sets of gene editing vectors, which were subsequently employed to transform the soybean cultivar ‘WM82’ and 'Jack.' Furthermore, we adapted the Tobacco rattle virus (TRV) and Apple latent spherical virus (ALSV) vectors for the delivery of guide RNAs, enabling precise gene editing events in the transgenic soybean plants. Consequently, transgenic soybean plants infected with these virus vectors have the capacity to yield mutant soybeans characterized by increased methionine and cysteine content. Through a rigorous process of cross-selection among the mutant lines, we aim to develop non-GMO soybean varieties that exhibit heightened levels of methionine and cysteine while simultaneously reducing allergenic properties.

The new non-GMO soybean cultivars will allow U.S. farmers to produce food-grade soybeans that can increase their profits, maintain their international competitiveness, and meet the needs of ever-growing domestic and global markets. These outcomes are thus expected to have a positive impact on human health and sustainability of U.S. soybean production, expanding niche market share and enhancing the U.S. soy value proposition in key organic markets in the world.