Soybean oil has a wide variety of uses, and stearic acid,
August 29, 2017
Soybean oil has a wide variety of uses, and stearic acid, which is a relatively minor component of soybean oil is increasingly desired for both industrial and food applications. the total oil fraction. Stearic acid has a neutral effect on blood serum LDL cholesterol concentration and is consequently a desirable constituent of oils for food use . Stearic acid confers a high melting buy LY2811376 heat and oxidative stability to oils destined for buy LY2811376 end use in baking body fat. Previously, to increase the proportion of stearic acid in soybean oil, the oil was subjected to hydrogenation. However, genetic manipulation of stearic acid level is more efficient and reduces the trans-fats that may be launched from the hydrogenation process . Three soybean genes have been characterized with homology to delta-9-stearoyl-acyl carrier protein desaturases (SACPDs) which are required for the conversion of stearic acid to oleic acid . These genes are delimited SACPD-A, SACPD-B, and SACPD-C. SACPD-C encodes the seed-specific isoform of this enzyme, where SACPD-A and SACPD-B transcripts accumulate in all soybean cells , . Soybeans buy LY2811376 with mutations in the SACPD-C and SACPD-B genes have been explained. FAM94-41 is definitely a spontaneously happening switch in the SACPD-C gene and results in plants with levels of stearic acid in the seed of 9% . Deletion of the SACPD-C gene in the ESR1 A6 germplasm collection results in up to 28% stearic acid in the seed, but the size of this deletion is definitely uncharacterized , . Additional SACPD-C mutants have been described with a range of 10-16% stearic acid in the seeds , . buy LY2811376 SACPD-B mutants have recently been reported to consist of 10% stearic acid . No mutations have been explained for the SACPD-A gene. Some high stearate mutants have previously been associated with poor germination and low seed yield ,  however recently it was exhibited that missense mutations in are not associated with poor agronomic characteristics . Additional sources of germplasm carrying novel mutations in the SACPD-C gene, or novel loci which influence seed stearic acid levels are needed to circumvent this issue to enable the production of soybeans with elevated levels of stearic acid to meet the demands of the food-oil market. Materials and Methods Plants and growth conditions and fatty acid analysis For screening, plants were produced in the field in West Lafayette, Indiana, as described in reference . Field location GPS coordinates are latitude 40.468 degrees north, longitude minus 86.991 degrees west. Soybeans described in this study are non-transgenic, therefore no specific permits were required for growth. Fatty acid composition analysis was performed as previously described . Sequencing and Genotyping Three segments of the SACPD-C (Glyma14g27990) coding region were amplified and sequenced using the primers in Table S1. DNA sample preparation for sequencing was performed using the CTAB method  and sample preparation for genotyping was as previously described . dCAPS genotyping  was performed using standard protocols with the assays developed specifically for the SACPD-C mutants provided in Table S1. To evaluate the position of substitutions, mutations were overlaid around the protein structure PDB ID 1AFR using the program Cn3D v. 4.3 . Mutant SACPD-C sequences are deposited in GenBank with accession buy LY2811376 numbers “type”:”entrez-nucleotide-range”,”attrs”:”text”:”KJ522450-KJ522455″,”start_term”:”KJ522450″,”end_term”:”KJ522455″,”start_term_id”:”631798726″,”end_term_id”:”631798736″KJ522450-KJ522455. Results and Discussion Mutant plants with high levels of stearic acid in seeds were identified in an ongoing screen for soybean seed with altered fatty acid composition (reference , and unpublished data) and six lines were chosen for further characterization. These mutants were.