Location: Plant Genetics ResearchTitle: A novel FAD2-1 A allele in a soybean plant introduction offers an alternate means to produce soybean seed oil with 85% oleic acid content) Author
Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/27/2011
Publication Date: 8/14/2011
Citation: Anh-Tung, P., Jeong-Dong, L., Grover, S.J., Bilyeu, K.D. 2011. A novel FAD2-1 A allele in a soybean plant introduction offers an alternate means to produce soybean seed oil with 85% oleic acid content. Journal of Theoretical and Applied Genetics. 123(5):793-802. Interpretive Summary: Commodity soybeans are poised to undergo a revolutionary change. Major shifts in market expectations for the nutritional quality of the oil, brought about in part through food labeling requirements and the suitability for biodiesel, are driving the commodity soybean to embrace new seed compositional qualities. Using conventional soybean breeding technology without transgenics, we discovered a new combination of the two genes responsible for the accumulation of oleic acid in soybean seed oil that caused the soybean seeds to produce an oil very similar in profile to olive oil. The impact of this research is the availability of technology to create soybean cultivars with oil profiles that can meet the expectations of the new commodity oil market. With soybeans high in oleic acid the competitiveness of the U.S. soybean industry will be greatly enhanced.
Technical Abstract: The alteration of fatty acid profiles in soybean to improve soybean oil quality has been a long-time goal of soybean researchers. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of soybean oil compared to other oils. In the lipid biosynthetic pathway, the enzyme fatty acid desaturase 2 (FAD2) is responsible for the conversion of oleic acid precursors to linoleic acid precursors in developing soybean seeds. Two genes encoding FAD2-1A and FAD2-1B were identified to be more expressed during embryogenesis. Twenty two soybean plant introduction (PI) lines identified to have an elevated oleic acid content were characterized for sequence mutations in the FAD 2-1A and FAD2-1B genes. PI 603452 was found to contain a deletion of a nucleotide in the second exon of FAD2-1A. These important SNPs were used in developing molecular marker genotyping assays, and the assays appear to be a reliable and accurate tool to identify the FAD 2-1A and FAD2-1B genotype of wild type and mutant plants. PI 603452 was subsequently crossed with PI 283327, a soybean line that has a mutation in FAD2-1B. Interestingly, soybean lines carrying both homozygous insertion/deletion mutation (indel) FAD2-1A alleles and mutant FAD2-1B alleles have an average of 82 to 86% oleic acid content, compared to 20% in conventional soybean, and low levels of linoleic and linolenic acids. The newly identified indel mutation in the FAD2-1A gene offers a simple method for the development of high oleic acid commercial soybean varieties.