Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2019
Publication Date: 7/11/2019
Citation: Held, J., Carrero-Colon, M., Hudson, K.A. 2019. Combination of novel FAD3C and FAD3A mutations for low linolenic acid soybeans. Molecular Breeding. 2:190006. https://doi.org/10.2134/age2019.01.0006.
Interpretive Summary: Soybean seed is a valuable source of oil for biofuels, industrial lubricants, and human consumption. Linolenic acid is a component of soybean oil that reduces the shelf-life and stability of the oil. Identifying and deploying the genes that control levels of linolenic acid in the seed oil will reduce production costs and eliminate chemical processing steps that can result in the creation of trans fats in the oil. In this study, the authors have identified a new genetic variant of the FAD3C gene that results in mutants with reduced levels of linolenic acid in soybean oil. These novel alleles can be used alone or in conjunction with other mutations to breed soybeans with an improved oil profile.
Technical Abstract: Conventional commodity soybean oil can typically have levels of the unsaturated linolenic acid up to 8% of the total oil fraction. As linolenic acid is unstable and contributes to off-flavors, and chemical saturation can produce harmful trans- fats, genetic alternatives for soybeans low in linolenic acid are desirable. We identified a novel mutant allele of the gene encoding the omega-3 desaturase FAD3C in a screen of a NMU-mutagenized population which resulted in a 2-3% reduction in linolenic acid levels. We measured the effect of combining this mutation with mutations in the homeologous FAD3A and the FAD2-1A desaturase on the soybean fatty acid profile to demonstrate that this polymorphism may be useful to breeders looking for conventional approaches to reduce linolenic acid levels. In particular, combinations of mutant alleles of FAD3A and FAD3C result in soybeans with linolenic acid comprising only 2-3% of the total fatty acids.