Fatty Acid Composition Of Seed Oil Research Articles

HO-CR and HOLL-CR: new forms of winter oilseed rape (Brassica napus L.) with altered fatty acid composition and resistance to selected pathotypes of Plasmodiophora brassicae (clubroot).

The priority in oilseed rape (Brassica napus L.) research and breeding programs worldwide is to combine different features to develop cultivars tailored to specific applications of this crop. In this study, forms with a modified fatty acid composition of seed oil were successfully combined with a source of resistance to Plasmodiophora brassicae Wor., a harmful protist-causing clubroot. Three HO-type recombinants in F6-F12 generations with oleic acid content of 80.2-82.1% and one HOLL-type F6 inbred mutant recombinant (HOmut × LLmut), with a high oleic acid content (80.9%) and reduced linolenic acid content (2.3%), were crossed with the cultivar Tosca, resistant to several pathotypes of P. brassicae. The work involved genotyping with the use of DNA markers specific for allelic variants of desaturase genes responsible for the synthesis of oleic and linolenic fatty acids, CAPS (FAD2 desaturase, C18:1), and SNaPshot (FAD3 desaturase, C18:3), respectively. Of 350 progenies in the F3 generation, 192 (55%) were selected for further studies. Among them, 80 HO (≥ 72%) lines were identified, 10 of which showed resistance to at least one up to four P. brassicae pathotypes. Thirty lines in the selected progeny contained high oleic acid and less than 5% linolenic acid; eight of them belonged to the HOLL type conferring resistance to at least one pathotype. Two HO lines and two HOLL lines were resistant to four pathotypes. The resulting HO-CR and HOLL-CR inbred lines with altered seed oil fatty acid composition and resistance to P. brassicae represent unique oilseed rape material with the desired combination of valuable traits.

The use of the principal component analysis in ranking hemp (<i>Cannabis sativa</i> L.) accessions according to the seed oil fatty acid composition for crop improvement

The use of modern methods for assessing the genotypic diversity of breeding material is effective in crop improvement. Interpretation of the results of a study of the fatty acid biochemical composition in seeds of hemp (Cannabis sativa L.) accessions is one of important stages in breeding oilseed varieties, since hemp possesses a unique fatty acid composition (FAC) among other oilseed crops in Russia. Studies of regularities in formation of seed oil FAC and the principal component analysis (PCA) of fatty acid contents have scientific significance and practical value for ensuring the acceleration of oilseed variety breeding aimed at improving quality and biological activity of oil. The use of PCA can be an effective in achieving this goal. The fatty acid profile of oil has been evaluated at the N.I. Vavilov Institute of Plant Genetic Resources in 25 hemp accessions from the VIR hemp collection. Local and industrial hemp varieties and breeding material of the Middle Russian ecotype were grown in Penza Province with a temperate continental climate on meadow-black soils of the Middle Volga Region of Russia. The seed oil FAC was studied using gas-liquid chromatography with mass spectrometry on an Agilent 6850 chromatograph. The results were processed using the UniChrom and AMDIS software. High content of omega-3 stearidonic fatty acid was found in accessions k-205 from Ukraine (1.23%) and k-168 from Russia (0.87%); that of α-linolenic acid in k-168 from Russia (0.82%) and k-224 from GDR (0.39%); of linoleic acid in k-154 (67.29%), k-360 (66.24%), and k-150 (64.58%) (all three from Russia); of γ-linolenic acid in k-88 from Russia (2.43%) and k-211 from GDR (1.92%). It has been established that the formation of hemp seed oil FAC is a multifactorial process. The main factor determined 27.8% of the variability. The presence of both positive and negative factor loadings was revealed. The highest factor loading for the variance of a complex of characters of the oil FAC is on the main factor, i.e. linoleic acid (+0.73). In relation to this acid, negative loadings were detected for myristic acid (−0.81), lauric acid (−0.78), palmitoleic acid (−0.72), and oleic acid (−0.72). The content of bioactive omega-6 diunsaturated linoleic acid was negatively associated with the content of omega-9 monounsaturated oleic acid, as well as with the content of polyunsaturated omega-6 γ-linolenic, omega-3 stearidonic, and omega-3 α-linoleic acids. The obtained information can be used for identifying accessions with the optimal FAC for their involvement in breeding oilseed hemp varieties.

Seed oil content and fatty acid composition in natural populations of Tarenaya longicarpa (Cleomaceae) during the dry and rainy seasons in Northeast Brazil

Seed oil content and fatty acid composition in natural populations of Tarenaya longicarpa (Cleomaceae) during the dry and rainy seasons in Northeast Brazil

Variation in Fruit Morphology and Seed Oil Fatty Acid Composition of Camellia oleifera Collected from Diverse Regions in Southern China

Camellia oleifera is an important woody edible oil crop in China with high ecological and economical values. It is a traditional oilseed crop with high levels of desirable fatty acids. The fruits of C. oleifera were harvested from 18 geographic provenances in southern China. In this paper, we analyzed the key environmental factors of diverse geographic provenances that caused the variation in the fruit morphology and fatty acid composition (FAC). Our study indicated an average coefficient of variation of fruit width (FW) of 18.63%, and 15.81% for fruit length (FL). The most abundant fatty acids (FA) were oleic acid (C18:1; 70.21–85.23%), followed by palmitic acid (C16:0; 6.93–13.89%) and linoleic acid (C18:2; 5.02–14.26%). In addition, the fruit width had a negative correlation with the equivalent latitude (ELAT) and a positive correlation with the annual mean air temperature (MAT). The fruit length-to-width ratio and oleic acid level had a positive correlation with ELAT but a negative correlation with MAT, annual precipitation (AP), and precipitation of wettest quarter (PWQ). A positive correlation was observed between MAT, AP, and PWQ with palmitic acid. Meanwhile, a negative correlation was found between longitude (LON), maximum temperature of warmest month (MTW), and ELAT and palmitic acid. The cluster analysis indicated six groups for the selected 18 populations. Our results showed the most influential environmental factors for variation in fruit morphology and FAC are ELAT and MAT.

Genome-wide approaches delineate the additive, epistatic, and pleiotropic nature of variants controlling fatty acid composition in peanut (Arachis hypogaea L.).

The fatty acid composition of seed oil is a major determinant of the flavor, shelf-life, and nutritional quality of peanuts. Major QTLs controlling high oil content, high oleic content, and low linoleic content have been characterized in several seed oil crop species. Here, we employ genome-wide association approaches on a recently genotyped collection of 787 plant introduction accessions in the USDA peanut core collection, plus selected improved cultivars, to discover markers associated with the natural variation in fatty acid composition, and to explain the genetic control of fatty acid composition in seed oils. Overall, 251 single nucleotide polymorphisms (SNPs) had significant trait associations with the measured fatty acid components. Twelve SNPs were associated with two or three different traits. Of these loci with apparent pleiotropic effects, 10 were associated with both oleic (C18:1) and linoleic acid (C18:2) content at different positions in the genome. In all 10 cases, the favorable allele had an opposite effect-increasing and lowering the concentration, respectively, of oleic and linoleic acid. The other traits with pleiotropic variant control were palmitic (C16:0), behenic (C22:0), lignoceric (C24:0), gadoleic (C20:1), total saturated, and total unsaturated fatty acid content. One hundred (100) of the significantly associated SNPs were located within 1000 kbp of 55 genes with fatty acid biosynthesis functional annotations. These genes encoded, among others: ACCase carboxyl transferase subunits, and several fatty acid synthase II enzymes. With the exception of gadoleic (C20:1) and lignoceric (C24:0) acid content, which occur at relatively low abundance in cultivated peanuts, all traits had significant SNP interactions exceeding a stringent Bonferroni threshold (α = 1%). We detected 7682 pairwise SNP interactions affecting the relative abundance of fatty acid components in the seed oil. Of these, 627 SNP pairs had at least one SNP within 1000 kbp of a gene with fatty acid biosynthesis functional annotation. We evaluated 168 candidate genes underlying these SNP interactions. Functional enrichment and protein-to-protein interactions supported significant interactions (P-value < 1.0E-16) among the genes evaluated. These results show the complex nature of the biology and genes underlying the variation in seed oil fatty acid composition and contribute to an improved genotype-to-phenotype map for fatty acid variation in peanut seed oil.

Generation of camelina mid-oleic acid seed oil by identification and stacking of fatty acid biosynthetic mutants

Modifying oilseeds to obtain a desired fatty acid composition is often necessary to enable use as feedstocks for specific applications such as food processing, biofuels, or biolubricants. A mutant population of camelina (Camelina sativa), an emerging specialty oilseed crop, was screened by high-throughput gas chromatography for lines with altered seed oil fatty acid composition. By leveraging knowledge of fatty acid synthesis in Arabidopsis thaliana, mutations in orthologs of FATTY ACID ELONGASE1 (FAE1), FATTY ACID DESATURASE2 (FAD2), FATTY ACID DESATURASE3 (FAD3), and β-KETO-ACYL-ACP SYNTHASE II (KASII; FAB1) were identified. The mutations altered conserved amino acid residues in the encoded proteins. The ability of the mutations in FAE1, FAD2 and FAD3 to affect enzyme function was demonstrated by comparing in vivo activities of wild-type and mutant alleles in yeast. In addition, expression of wild-type cDNA in camelina complemented fatty acid phenotypes of these mutants. As camelina has a hexaploid genome, the effect of a mutation in one of the three homeologs for each gene resulted in no or less severe growth phenotypes compared to similar mutations in Arabidopsis. Mid-oleic oils with nearly 40 % oleic acid and reduced very long-chain (≤C20) fatty acid content were obtained by crossing to obtain a fae1c/fad2a/fae1a/fad3a quadruple mutant. Little effect on total seed oil content was observed in the stacked mutant line. The resulting mid-oleic acid oil had improved oxidative stability due to reductions in polyunsaturated fatty acid content, increasing its utility for biofuels and other applications.

Genetic structure and diversity of Iranian Cannabis populations based on phytochemical, agro-morphological and molecular markers

Hemp (Cannabis sativa) is an herbaceous, annual, and dioecious plant belongs to the Cannabaceae family and grows in some parts of Iran. In the present study, the genetic diversity between and within the populations of 10 local cultivated landraces from Iran was evaluated, using multiple datasets (agro-morphological and biochemical traits, seed oil fatty acid compositions, and ISSR (Inter simple sequence repeats) markers. The analysis of variance based on the morpho-biochemical traits and oil compositions indicated significant differences among studied hemp populations (P < 0.01). Of the identified fatty acids, linoleic acid (53.02 %), α-linolenic acid (18.98 %), oleic acid (15.20 %), palmitic acid (6.61 %), and stearic acid (2.96 %) composed 77.79 % of total seed oil content. The content of major fatty acids varied greatly among the populations. Kermanshah had the highest proportion of linoleic acid (54.03 %), Hamedan; α-linolenic acid (21.47 %), Alborz; oleic acid (16.75 %), Kohkylouih-and-Boyerahmad; palmitic acid (6.82 %), and Khuzestan; stearic acid (3.23 %). In this study, 14 ISSR primers, produced 231 high-resolution bands, of which 198 (85 %) were polymorphic. Population structure inference showed that the hemp single plants in populations were distributed into six genetic clusters that were matched with UPGMA clusters. The results showed that the highest genetic distance was observed between Kerman and Markazi populations. The findings of this study can be used in future programs for the breeding of Iranian hemp landraces.

The Potential of Genome Editing for Improving Seed Oil Content and Fatty Acid Composition in Oilseed Crops.

A continuous rise in demand for vegetable oils, which comprise mainly the storage lipid triacylglycerol, is fueling a surge in research efforts to increase seed oil content and improve fatty acid composition in oilseed crops. Progress in this area has been achieved using both conventional breeding and transgenic approaches to date. However, further advancements using traditional breeding methods will be complicated by the polyploid nature of many oilseed crops and associated time constraints, while public perception and the prohibitive cost of regulatory processes hinders the commercialization of transgenic oilseed crops. As such, genome editing using CRISPR/Cas is emerging as a breakthrough breeding tool that could provide a platform to keep pace with escalating demand while potentially minimizing regulatory burden. In this review, we discuss the technology itself and progress that has been made thus far with respect to its use in oilseed crops to improve seed oil content and quality. Furthermore, we examine a number of genes that may provide ideal targets for genome editing in this context, as well as new CRISPR-related tools that have the potential to be applied to oilseed plants and may allow additional gains to be made in the future.

Registration of four upland cotton germplasm lines with elevated levels of seed oil oleic acid

AbstractFour upland cotton (Gossypium hirsutum L.) germplasm lines, HOa1 (Reg. no. GP‐1072, PI 691652), HOa2 (Reg. no. GP‐1073, PI 691653), HOa3 (Reg. no. GP‐1074, PI 691654), and HOa4 (Reg. no. GP‐1075, PI 691655), with elevated levels of seed oil oleic acid were developed and released by the USDA‐ARS. High seed oil levels of oleic acid have been reported for a small number of G. barbadense L. accessions. Included among these accessions is GB713, which is also known as a source of reniform nematode (Rotylenchulus reniformis Linford and Oliveira) resistance and has been used to breed this trait into an upland cotton background. Root‐knot nematode resistance was bred into the GB713‐based reniform‐resistant lines to yield germplasm with resistance to both nematodes. Testing the nematode‐resistant lines for seed oil fatty acid composition revealed elevated levels of oleic acid in some seeds. Selection and propagation of individual plants with the highest oleate levels indicated that the trait was stable for three successive generations with approximately double the level of oleic acid found in normal cottonseed oil. Oils with high levels of oleic acid are considered to be healthier and have improved oxidative stability at elevated temperature, making them preferred for some cooking and frying applications.

Seed oil content and fatty acid composition response to ethyl methanesulphonate mutagenesis in vernonia

Vernonia [Centrapalus pauciflorus (Willd.) H.Rob.] is a novel industrial oilseed crop that can be used to produce vernolic acid, a naturally epoxidised fatty acid. The study objective was to determine whether ethyl methylsulphonate (EMS) mutagenesis significantly altered seed oil content and fatty acid compositions in selected vernonia accessions. Seeds were harvested from mutant plants with and without visual chlorophyll mutations from the Vge-1 and Vge-4 vernonia accessions, subjected to seed oil content and fatty acid composition analyses and compared with untreated controls. Visual chlorophyll mutations confirmed EMS mutation in harvested plants. Ethyl methylsulphonate mutagenesis significantly reduced vernolic acid composition, and significantly increased linoleic, oleic, palmitic, stearic and arachidic acid composition in the Vge-1 accession. In Vge-4, palmitic acid composition was significantly increased. Results obtained suggested that the effect of EMS mutagenesis on fatty acid composition in vernonia could be accession-specific and influenced by mutation level. The significant but negative association between vernolic acid and other fatty acids indicates that there is potential to increase vernolic acid while at the same time reducing the contents of other fatty acids through EMS mutagenesis in vernonia. There is a need to assess EMS mutagenesis impact on seed oil over successive generations to confirm results from this study.

Synthesis of fatty phenylthiosemicarbazide from underutilized Sesamum indicum seed oil: a promising corrosion inhibitor of carbon steel in developing country

Fatty phenylthiosemicarbazide (FP) was synthesized from Sesamum indicum seed oil (SO) via simple reaction mechanism, which was characterized using Fourier transform infrared and proton nuclear magnetic resonance (1HNMR). Fatty acid composition of SO was examined using gas chromatography (GC) coupled with flame ionization detector while FP was evaluated for its ability to inhibit corrosion in carbon steel using weight loss method. Quantum chemical computation using density functional theory was applied to gain theoretical insight on the inhibition capacity of FP. The result of the GC revealed the most dominant fatty acid in SO to be C18:2 (43.77%) while the least was C16:1 (0.10%). FP exhibited a corrosion inhibition efficiency of 62.55% at room temperature but increased to 99.57% at 303 K, which obeyed Langmuir isotherm. The $$\Delta G_{ads}^{^\circ }$$ value revealed the process to be spontaneous while both $$\Delta H_{ads}^{^\circ }$$ (− 1.088 kJ mol−1) and $$\Delta S^{^\circ }$$ (− 0.015 kJ mol−1 K−1) suggested an exothermic process. The lowest unoccupied molecular orbital and highest occupied molecular orbital were distributed over the molecule of FP with an activation energy of 25.606 kJ mol−1. The current study presents FP as a promising corrosion inhibitor, which can replace synthetic compounds from petrochemicals used as corrosion inhibitors in developing countries.

Effects of Sowing Season on Agronomic Traits and Fatty Acid Metabolic Profiling in Three Brassica napus L. Cultivars.

Decreasing saturated fatty acids and increasing monounsaturated fatty acids are desirable to improve oil for food. Seed oil content and fatty acid composition are affected by genotype and environment. Therefore, we systematically analyzed the agronomic traits and fatty acid metabolic profiling of Brassica napus (B. napus) seeds at different developmental stages in high level of oleic acid (HOA), medium level of oleic acid (MOA), and low level of oleic acid (LOA) B. napus cultivars, both sown in winter and summer. The results showed that all winter-sown cultivars produced 20% more seed yield than the summer-sown crop. The longer growing period of winter-sown B. napus resulted in higher biomass production. However, the fatty acid metabolism of individual cultivars was different between winter-sown rape (WAT) and summer-sown rape (SAT). The absolute fatty acid content of LOA and MOA cultivars in WAT were significantly higher than that in SAT, but that of HOA was opposite. Importantly, the levels of monounsaturated fatty acids (18:1; 20:1) in SAT were far more than those in WAT. These data indicate the quality of oil from the HOA in SAT is more suitable for human consumption than that in WAT.

The effect of light conditions on interpreting oil composition engineering in Arabidopsis seeds.

Arabidopsis thaliana is the most developed and utilized model plant. In particular, it is an excellent model for proof‐of‐concept seed oil engineering studies because it accumulates approximately 37% seed oil by weight, and it is closely related to important Brassicaceae oilseed crops. Arabidopsis can be grown under a wide variety of conditions including continuous light; however, the amount of light is strongly correlated with total seed oil accumulation. In addition, many attempts to engineer novel seed oil fatty acid compositions in Arabidopsis have reported significant reductions in oil accumulation; however, the relative reduction from the nontransgenic controls varies greatly within the literature. A set of experiments were conducted to systematically analyze the effect of light conditions (including day/night cycle vs. continuous light, and different light intensities) on the relative accumulation of seed oil between three different transgenic lines producing novel hydroxy fatty acids and their nontransgenic background. Oil content was measured per seed and as a percentage of seed weight. Our results indicate the relative amount of seed oil between transgenic lines and nontransgenic controls is dependent on both the light conditions and the type of oil content measurement utilized. In addition, the light conditions effect the relative accumulation of the novel fatty acids between various transgenic lines. Therefore, the success of novel fatty acid proof‐of‐concept engineering strategies on both oil accumulation and fatty acid composition in Arabidopsis seeds should be considered in light of the select growth and measurement conditions prior to moving engineering strategies into crop plants.

Erratum to: Variation in Seed Oil Content and Fatty Acid Composition of Globe Artichoke Under Different Irrigation Regimes

Seed oil content of globe artichoke and its composition were assessed under three irrigation regimes, including irrigation at 20, 50, and 80 % depletion of soil available water. Water deficit affected the phenological characteristics, amount and the quality of the oil as well as the phenolics and antioxidant activity of the leaves and capitula. The seed oil content ranged from 18.7 % in 80 % to 22.8 % in 20 % treatment. The fatty acid composition of oil was determined using gas chromatography (GC). The predominant fatty acids in the oil were linoleic (51.68 %), oleic (34.22 %), palmitic (9.94 %), and stearic (3.58 %). Water deficit leads to reduced oil content, linoleic acid, the unsaturated/saturated fatty acid ratio and the iodine value. On the other hand, some other fatty acids such as palmitic and oleic acid and also the ratio of oleic/linoleic acid were elevated due to water deficit. Higher antioxidant activity was observed in capitula (IC50 = 222.6 μg ml−1) in comparison to the leaves (IC50 = 285.8 μg ml−1). Finally, the severe drought stress condition caused to gain higher oil stability, while the highest seed oil content and unsaturated fatty acids in the oil was obtained in non-stress condition. Moreover, high phenolics, flavonoids and antioxidant activity as well as appreciable dry matter content were obtained in the moderate water stress condition.

Variation in Seed Oil Content and Fatty Acid Composition of Globe Artichoke Under Different Irrigation Regimes

AbstractSeed oil content of globe artichoke and its composition were assessed under three irrigation regimes, including irrigation at 20, 50, and 80 % depletion of soil available water. Water deficit affected the phenological characteristics, amount and the quality of the oil as well as the phenolics and antioxidant activity of the leaves and capitula. The seed oil content ranged from 18.7 % in 80 % to 22.8 % in 20 % treatment. The fatty acid composition of oil was determined using gas chromatography (GC). The predominant fatty acids in the oil were linoleic (51.68 %), oleic (34.22 %), palmitic (9.94 %), and stearic (3.58 %). Water deficit leads to reduced oil content, linoleic acid, the unsaturated/saturated fatty acid ratio and the iodine value. On the other hand, some other fatty acids such as palmitic and oleic acid and also the ratio of oleic/linoleic acid were elevated due to water deficit. Higher antioxidant activity was observed in capitula (IC50 = 222.6 μg ml−1) in comparison to the leaves (IC50 = 285.8 μg ml−1). Finally, the severe drought stress condition caused to gain higher oil stability, while the highest seed oil content and unsaturated fatty acids in the oil was obtained in non‐stress condition. Moreover, high phenolics, flavonoids and antioxidant activity as well as appreciable dry matter content were obtained in the moderate water stress condition.

Cultivar and Seasonal Effects on Seed Oil Content and Fatty acid Composition of Cucumber As a Potential Industrial Crop

Cucumber (Cucumis sativus) seed oil has the potential for use as an edible oil and as a pharmaceutical, cosmetic, insecticidal, and industrial product. In this study, we investigated, for the first time, the effect of cultivar and season on seed number, oil content, and fatty acid profiles as well as their proportions in different cucumber cultivars. We examined the effects of spring and autumn seasons on seed oil content and fatty acid composition in 46 cucumber cultivars and one wild species of cucumber (C. anguria) grown in greenhouse experiments in 2013 and 2014. Seed oil was determined using the Soxhlet method and fatty acids using the gas chromatography-mass spectrometry method. Seed oil content in the cucumber seeds ranged from 41.07% in ‘Hazerd’ to 29.24% in ‘Lubao’ while C. anguria had 23.3%. Fatty acids detected were linoleic (C18:2), palmitic (C16:0), oleic (C18:1), stearic (C18:0), linolenic (C18:3), behenic (C22:0), arachidic C20:0), lignoceric (C24:0), eicosenoic (C20:1), palmitoleic (C16:1), and myristic (C14:0), among other unidentified fatty acids. The results showed significant effects of cultivar genotype, growing season, and interactions on the variables examined. The content of seed oil and fatty acids differed significantly among the cultivar genotypes. Spring-grown cucumbers had higher quantities of oil than the autumn-grown cucumbers. The content of fatty acids (mainly palmitic, palmitoleic, stearic, oleic, eicosenoic, and lignoceric) also was higher in spring. In autumn there were more seeds, and higher linoleic, linolenic, and other unspecified fatty acids. The higher the oleic acid content the lower was the linoleic acid indicating a strong negative relationship in these two fatty acids. The higher the seed oil content the higher was linoleic and oleic indicating a positive relationship between the seed oil and the two fatty acids. Results of this study provide important information applicable in improving management and production of cucumber seed oil especially considering its versatility in uses. Furthermore, the wide range of fatty acids found in the studied cucumber cultivars could be used in the production of novel industrial oils through genetic engineering.

Global lipidomics profiling of cotton seed oil genotypes using CO2-based chromatography coupled to mass spectrometry

Refined cottonseed oil enjoys widespread applications in the food and chemical industries. Although the major lipids comprising cottonseed oil are well known, there are many diverse lipid species in cotton seeds that occur at much lower levels and have important nutritional or anti-nutritional properties. Lipidomics analysis of complex lipids in seed oil extracts using a single chromatographic technique is challenging due to the diversity of lipid polarity and the large range of concentrations of lipid species in biological samples. Ultra Performance Convergence Chromatography (UPC2) is a chromatographic system that utilizes liquid CO2 as primary solvent and co-solvents such as methanol as a mobile phase to leverage the chromatographic principles and selectivity of normal phase chromatography while providing the ease-of-use of reversed-phase LC. We have used UPC2 coupled to mass spectrometry for the separation of free fatty acids, neutral and polar lipids in a single cotton seed lipid extract. Several seed oil genotypes, including high oleic acid line of Gossypium hirsutum cv. Coker 312 with a nonfunctional Brassica napus allele of delta-12 fatty acid desaturase (FAD2) and naturally occurring high oleic acid line of G. barbadense, were profiled to identify global consequences of modulating seed oil fatty acid composition. Potential markers that discriminate the different genotypes were identified and quantified.

Genetic and Environmental Effects on Fatty Acid Composition in Soybeans with Potential Use in the Automotive Industry

ABSTRACTEnvironmental effects on quantitative traits such as seed oil fatty acid composition in soybean [Glycine max (L.) Merrill] can significantly affect the performance of a given genotype when exposed to varying growing conditions. High linoleic acid oils have the potential to be used as raw materials for the production of polyols and polyurethane that can be used in the automotive industry. The objectives of this study were (i) to determine the sources of variation affecting seed oil fatty acids profiles and (ii) to evaluate stability of soybean genotypes with different fatty acids across different environments. Fifty‐six soybean genotypes with altered fatty acid composition selected from two recombinant inbred line populations segregating for saturated and linoleic acids were used along with commercial high yielding cultivars. All genotypes were evaluated in southwestern Ontario, Canada, at three locations in 2008 and two locations in 2009, and data was collected for fatty acid composition as well as other seed and agronomic traits. Combined analysis of variances showed significant location and genotype × location effects for stearic and oleic acids. Genotype × environment effect was significant for unsaturated fatty acids plus seed oil and protein concentrations. The effect of genotype × year was significant for unsaturated fatty acids. Stability analyses using Francis and Kannenberg's mean coefficient of variation stability, Shukla's stability variance statistic (σ2), and Lin and Binns cultivar superiority measure identified genotypes E‐49 and E‐14 as being superior for high linoleic and low saturated fatty acids oil production for potential use in the automotive industry.

Effects of phylogeny and climate on seed oil fatty acid composition across 747 plant species in China

Seed oil has long been recognized as an important source of food, industry and biodiesel. In biological aspect, seed oil fatty acid composition (FAC) affects lipid fluidity and cellular metabolism, depending on temperature. Hence, the variation of FAC in seeds may reflect adaptive strategies for seed survival and seedling establishment under contrasting climate conditions. In this study, we investigated the relative effects of phylogeny and climate on seed oil FAC, testing the hypothesis that the degree of fatty acid unsaturation increases in colder climates. A large seed oil FAC dataset representing 747 species from 207 sites across China was compiled and a general linear model was used to partition total variance in FAC into taxonomic ranks (family, genus and species) and environmental components. Multiple regression analysis was conducted to examine the relative effects of mean annual temperature (MAT) and mean annual precipitation (MAP). Phylogenetically independent contrast (PIC) analysis was used to test the evolutionary association of FAC with climate at the family level. The results showed that seed oil FAC varied considerably across plant species, with phylogeny explaining a greater proportion of variance than environment; however, FAC showed obvious large-scale spatial patterns. Total unsaturated fatty acid (UFA) content increased with increasing latitude. The degree of fatty acid unsaturation, as indicated by the ratio of UFA to saturated fatty acids and iodine value, was negatively correlated with MAT and to a lesser extent with MAP. The PIC results indicated that at the family level, nearly all significant phenotypic correlations of FAC with spatial and climatic variables were evolutionarily convergent. These results indicate that despite strong phylogenetic constraints on FAC, fatty acid unsaturation in seed oil appears to evolve as an adaptive strategy in colder climates. The affiliation of phylogenetic and climate in seed oil FAC may assist in the search of potential oil plants with particular FAC for food and fuel needs.

Acyl-ACP thioesterases from Camelina sativa: Cloning, enzymatic characterization and implication in seed oil fatty acid composition

Acyl-acyl carrier protein (ACP) thioesterases are intraplastidial enzymes that terminate de novo fatty acid biosynthesis in the plastids of higher plants by hydrolyzing the thioester bond between ACP and the fatty acid synthesized. Free fatty acids are then esterified with coenzyme A prior to being incorporated into the glycerolipids synthesized through the eukaryotic pathway. Acyl-ACP thioesterases belong to the TE14 family of thioester-active enzymes and can be classified as FatAs and FatBs, which differ in their amino acid sequence and substrate specificity. Here, the FatA and FatB thioesterases from Camelina sativa seeds, a crop of interest in plant biotechnology, were cloned, sequenced and characterized. The mature proteins encoded by these genes were characterized biochemically after they were heterologously expressed in Escherichia coli and purified. C. sativa contained three different alleles of both the FatA and FatB genes. These genes were expressed most strongly in expanding tissues in which lipids are very actively synthesized, such as developing seed endosperm. The CsFatA enzyme displayed high catalytic efficiency on oleoyl-ACP and CsFatB acted efficiently on palmitoyl-ACP. The contribution of these two enzymes to the synthesis of C. sativa oil was discussed in the light of these results.