|Ruddle, Paul - North Carolina State University|
|Cardinal, Andrea - Syngenta|
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2013
Publication Date: 2/1/2014
Citation: Ruddle, P., Cardinal, A., Upchurch, R.G., Miranda, L.M. 2014. Effect of Delta 9–Stearoyl-ACP-Desaturase-C mutants in a high oleic background on soybean seed oil composition. Theoretical and Applied Genetics. Vol. 127, pp. 349-358.
Interpretive Summary: Soybean oil with high Stearic acid content could be used for the oil industry to substitute imported solid fats high in palmitic acid, with the added advantage of not having the negative health effects associated with short chain saturated fats. This research identified two novel SACPD-C (Delta 9–stearoyl-acyl carrier protein-desaturase) deletions of different size present in two different lines selected from a mutagenized population of the cultivar Holladay (TCHM08-1087 and TCHM08-755). The effect of SACPD-C mutations in a high oleic background was also studied in two populations. One of them was a cross between a SACPD-C deletion and a high oleic line, and the other was a cross between a SACPD-C point mutation and a high oleic line. No interaction was observed between the high stearic and the high oleic loci in either cross but the observed higher stearic acid content in the progeny of the cross between the high oleic and the line carrying the SACPD-C point mutation indicates that this line harbors another yet unidentified locus that affects stearic acid concentration.
Technical Abstract: Soybean [Glycine max (L.) Merr.] oil typically contains 2-4% stearic acid. Oil with at least 20% stearic acid is desirable because of its baking properties and health profile. This study identifies two new sources of high stearic acid and evaluates the interaction of high stearic and oleic acid alleles. TCHM08-1087 and TCHM08-755, high stearic acid ‘Holladay’ mutants, were crossed to FAM94-41-3, a line containing a point mutation in a seed-specific isoform of a Delta 9–stearoyl-acyl carrier protein-desaturase (SACPD-C). F2-derived lines were evaluated for fatty acid content in four field environments. Sequencing of SACPDs in TCHM08-1087 and TCHM08-755 revealed a deletion of at least one megabase encompassing SACPD-C in both lines. After genotyping, the additive effect for stearic acid was estimated at +1.8 for the SACPD-C point mutation and +4.1 for the SACPD-C deletions. Average stearic acid in lines homozygous for the deletions was 12.2%. A FAM94-41-3-derived line and TCHM08-1087-11, a selection from TCHM08-1087, were crossed to S09-2902-145, a line containing missense mutations in two fatty acid desaturases (FAD2-1A and FAD2-1B). F1 plants were grown in a greenhouse and individual F2 seed were genotyped and phenotyped. No interaction was observed between either FAD2-1A and FAD2-1B and either of the SACPD-C mutant alleles. Seed homozygous mutant for SACPD-C/FAD2-1A/FAD2-1B contained 12.7% stearic acid and 65.5% oleic acid while seed homozygous for the SACPD-C deletion and mutant for FAD2-1A and FAD2-1B averaged 10.4% stearic acid and 75.9% oleic acid. The SACPD-C deletions in TCHM08-1087 and TCHM08-755 shall be designated fasncdel1 and fasncdel2 respectively.