Location: Plant Genetics ResearchTitle: Combinations of mutant FAD2 and FAD3 genes to produce high oleic acid and low linolenic acid soybean oil Author
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2012
Publication Date: 7/18/2012
Publication URL: http://handle.nal.usda.gov/10113/54541
Citation: Pham, A., Shannon, G.J., Bilyeu, K.D. 2012. Combinations of mutant FAD2 and FAD3 genes to produce high oleic acid and low linolenic acid soybean oil. Theoretical and Applied Genetics. 125:503-515. Interpretive Summary: The fatty acid profile of vegetable oil determines the ultimate utilization that the oil is most suited for in both food applications and for industrial uses. We recently created soybean seeds containing a high oleic acid content in the oil, a trait that will improve the oxidative stability of the oil and offer the ability to replace the functionality of partially hydrogenated soybean oil without the production of trans fatty acids. The objective of this research was to determine the genetics responsible for further reducing the oxidatively unstable linolenic acid component of the oil when the seeds contained a high oleic acid content. The results demonstrated that combinations of three or four mutant genes could produce soybean oil with the desired fatty acid profiles, depending on the source of the genes, and also on the environment used for seed production. The impact of this research is the advancement of understanding the target gene combinations to develop more functional soybean oils.
Technical Abstract: High oleic acid soybeans were produced by combining a mutant FAD2-1A and a mutant FAD2-1B gene. Despite having a high oleic acid content, the linolenic acid content of these soybeans was in the range of 4-6%. Therefore, a study was conducted to incorporate one or two mutant FAD3 genes into the high oleic acid background to further reduce the linolenic acid content. As a result, soybean lines with high oleic acid and low linolenic acid (HOLL) content were produced using different sources of mutant FAD2-1A genes. While oleic acid content of these HOLL lines was stable across two testing environments, the reduction of linolenic acid content varied depending on the number of mutant FAD3 genes combined with mutant FAD2-1 genes, on the severity of mutation in the FAD2-1A gene, and on the testing environment. Combination of two mutant FAD2-1 genes and one mutant FAD3 gene resulted in less than 2% linolenic acid content in Portageville, Missouri while four mutant genes were needed to achieve the same amount of linolenic acid content in Columbia, Missouri. This study generated non-transgenic soybeans with the highest oleic acid content and lowest linolenic acid content reported to date, offering a unique alternative to produce a fatty acid profile similar to olive oil.