title: Effect of a novel mutation in a Δ9-stearoyl-ACP-desaturase on soybean seed oil composition.
abstract: Soybean [Glycine max (L.) Merr.] oil typically contains 2-4% stearic acid. Seed oil with 20% stearic acid would be useful for solid fat applications, both for its cooking properties and health benefits. Breeding lines with high stearic acid have been developed, but many suffer from agronomic problems. This study identifies a new source of high stearic acid, determines its relationship with another high stearic locus and presents molecular markers for it is use in breeding. TCJWB03-806-7-19, a 'Holladay' mutant with high stearic acid, was crossed to two FAM94-41-derived lines that contained a point mutation in a seed-specific isoform of a Δ9-stearoyl-acyl carrier protein-desaturase (SACPD-C). Fatty acid analysis was performed over two growing seasons with F(2)-derived lines and transgressive segregation for stearic acid content was observed. Sequencing of SACPD isoforms in TCJWB03-806-7-19 revealed the deletion of an 'A' nucleotide in exon 3 of SACPD-B, which results in a protein whose final 28 amino acids are predicted to differ from Williams 82 SACPD-B. Sorting intolerant from tolerant (SIFT) analysis revealed that this frameshift mutation may affect SACPD-B protein function. Allele-specific genotyping for the SACPD-C point mutation and SACPD-B nucleotide deletion was performed in both populations. Additive effects and R(2) for stearic acid were +3.3 and 0.55 for SACPD-C and +1.9 and 0.19 for SACPD-B. Average stearic acid in lines homozygous for both mutations was 14.6%. This SACPD-B mutation represents a novel high stearic allele.
authors.affiliation: Department of Crop Science, North Carolina State University, Box 7620, Raleigh, NC 27695, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Ruddle
authors.forename: Rebecca
authors.initials: R
authors.lastname: Whetten
authors.forename: Andrea
authors.initials: A
authors.lastname: Cardinal
authors.forename: Robert G
authors.initials: RG
authors.lastname: Upchurch
authors.forename: Lilian
authors.initials: L
authors.lastname: Miranda
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D003433:Crosses, Genetic; D017931:DNA Primers / Q000235:genetics; D005091:Exons; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism; D017353:Gene Deletion; D017343:Genes, Plant; D005838:Genotype; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D009711:Nucleotides / Q000235:genetics; D018515:Plant Leaves / Q000378:metabolism; D020033:Protein Isoforms; D017386:Sequence Homology, Amino Acid; D013024:Soybean Oil / Q000235:genetics*; D013229:Stearic Acids / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D005227:Fatty Acids; D009711:Nucleotides; D020033:Protein Isoforms; D013229:Stearic Acids; C031183:stearic acid; D013024:Soybean Oil; D044943:Fatty Acid Desaturases; C433487:stearoyl ACP desaturase, Arabidopsis