title: Lipid characterization of seed oils from high-palmitic, low-palmitoleic, and very high-stearic acid sunflower lines.
abstract: Information obtained in recent years regarding the enzymes involved in FA synthesis can now be applied to develop novel sunflower lines by incorporating enzymes with specific characteristics into lines with a defined background. We have generated three highly saturated mutant lines in this way and characterized their FA content. The new high-palmitic, low-palmitoleic lines CAS-18 and CAS-25, the latter on a high-oleic background, have been selected from the high-stearic mutant CAS-3 by introducing a deficient stearic acid desaturase in a high-palmitic background from the previously developed mutant lines CAS-5 and CAS-12, respectively. As such, the desaturation of palmitic acid and the synthesis of palmitoleic acid and its derivatives (asclepic and palmitolinoleic acids) were reduced in these high-palmitic lines, increasing the stearic acid content. Likewise, introducing a FA thioesterase from a high-palmitic line (e.g., CAS-5) into the high-stearic CAS-3 increased the stearic acid content from 27 to 32% in the new high-stearic line CAS-31. As previously described in high-palmitic lines, high growth temperatures did not reduce the linoleic acid content of the oil. Furthermore, the FA composition of TAG, DAG, and phospholipids was modified in these lines. Besides a high degree of saturation, the TAG from these new vegetable oils have a low content of saturated FA in the sn-2 position. The alpha asymmetric coefficient obtained also indicates that the saturated FA are asymmetrically distributed within the TAG molecules. Indeed, the disaturated TAG content rose from 31.8 to 48.2%. These values of disaturated TAG are the highest to date in a temperate oilseed.
authors: Instituto de la Grasa, Consejo Superior de Investigaciónes Científicas (CSIC), 41012 Sevilla, Spain.
authors: María J
authors: MJ
authors: Serrano-Vega
authors: Enrique
authors: E
authors: Martínez-Force
authors: Rafael
authors: R
authors: Garcés
mesh_terms: D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D006368:Helianthus / Q000737:chemistry* / Q000235:genetics; D006824:Hybridization, Genetic; D008055:Lipids / Q000737:chemistry*; D019308:Palmitic Acid / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*; D030821:Plants, Genetically Modified; D012639:Seeds / Q000737:chemistry*; D013229:Stearic Acids / Q000737:chemistry; D013696:Temperature; D014280:Triglycerides / Q000737:chemistry
chemical_list: D005229:Fatty Acids, Monounsaturated; D008055:Lipids; D010938:Plant Oils; D013229:Stearic Acids; D014280:Triglycerides; C008757:palmitoleic acid; D019308:Palmitic Acid; C031183:stearic acid