Fatty Acid Composition Of Seeds Research Articles

Total oil and fatty acid composition of the seed of 16 grape genotypes with different skin colors and ripening times

BACKGROUND: Grapes, which have gained prominence in recent years due to their positive contributions to human health, are considered a functional food due to the oil content in their seeds. Although the oil content and fatty acid composition of commonly grown grape varieties have been the subject of many studies, these characteristics of local varieties haven’t been sufficiently examined. OBJECTIVE: This study was carried out to determine the usability of grape varieties grown in Southeastern Anatolia (Turkey) in grape seed oil production and identify potential parent candidates that could be used in the breeding of grape varieties with high-quality seed oil. METHODS: The effects of genotypes, berry skin color, ripening time, and the climatic characteristics of the cultivation season on the oil content and fatty acid composition of seeds from 16 different grape (Vitis vinifera L.) varieties were investigated. Grape seed oils were extracted by soxhlet device and major, minor, and essential fatty acid compositions were determined by gas chromatography. RESULTS: According to the findings, the oil content of the grape seeds varied only depending on the genotype and ranged from 9.78% to 18.50% w/w. Moreover, 13–15 fatty acids were detected in the grape seed oils, with linoleic acid (56.13% –69.36%) and oleic acid (15.99% –30.97%) being the most common in all varieties. Only palmitic acid and stearic acid showed variation depending on the skin color; the other fatty acids weren’t affected. Cultivation season didn’t affect the fatty acid composition, but the major and minor fatty acid composition varied depending on ripening time. CONCLUSIONS: In cases where it isn’t possible to separate the seeds of grape varieties on a variety basis, classifying them according to the ripening time of the berries may be helpful in predicting the amounts of major, minor fatty acids and partially essential fatty acids in the seeds.

Seed Fatty Acid Changes Germination Response to Temperature and Water Potentials in Six Sesame (Sesamum indicum L.) Cultivars: Estimating the Cardinal Temperatures

Seed fatty acid composition can influence seed quality, followed by seed germination and optimal seedling establishment. Therefore, to find out the role of seed fatty acids in changing the cardinal temperatures of six sesame cultivars germinated at different temperatures (10, 15, 20, 25, 30, 35, 40, and 45 °C) and water potentials (0, −0.2, −0.4, −0.6, −0.8, −1, and −1.2 MPa), an experiment was conducted. The dent-like, beta, and segmented models were used to analyze the data. The results showed that different cultivars at optimal temperatures show different reactions to environmental conditions; for example, the germination rate in Halil and Dashtestan2 cultivars followed the dent-like model, Darab1, Oltan, and Yellow-White followed the beta model, and Naz followed the segmented model. Based on the results, the average temperature in all water potentials of the base, sub-optimal, supra-optimum, and ceiling was determined as 12.6, 33.3, 38, and 43.9 °C, respectively, once the superior dent-like model was used. Using the superior beta model, the average temperatures in the base, optimum, and ceiling were 8.5, 31.2, and 50.5 °C. In contrast, when the segmented superior model was used, they were determined to be 7.6, 34, and 44.1 °C, respectively. According to the results, it can be stated that the Halil cultivar with more oleic acid and less linoleic acid has a higher base temperature and is more adapted to high temperatures for later cultivations. The Naz cultivar with a long biological clock is suitable for earlier cultivations. The ceiling temperature of these cultivars was also affected by the osmotic potential and decreased significantly with the increase in osmotic levels. Dashtestan2 cultivar with a high germination rate could be chosen for cultivation in water and high-temperature stress areas.

Nitrogen compounds and fatty acid composition in seeds of amaranth varieties

Purpose. To determine the peculiarities of the formation of the nitrogen component and the fatty acid composition in amaranth seeds of different varieties.
 Methods. Laboratory (determination of the content of protein, amino acids, fatty acids, carbohydrates), calculation (integral score), mathematical and statistical.
 Results. The conducted studies show that amaranth seeds had a high protein content amounting to 16.1–24.7%. At the same time, it varied significantly over the studied varieties. Thus, significantly higher protein content was in amaranth variety ‘Kharkivskyi 1’ (24.7%) compared to other varieties. The lowest protein content was in ‘Helios’ variety (16.1%). It was found that phenylalanine dominates among essential amino acids in amaranth seeds, with the content ranging in the studied varieties between 981 and 1155 mg/100. The content of tryptophan was the lowest, 155–206 mg/100 g. The highest content of amino acids was determined in variety ‘Kharkivskyi 1’. The seeds of this variety exceeded the seeds of the ‘Helios’ variety by 30–33% in terms of the content of threonine, tryptophan, and isoleucine, by 17–20% of phenylalanine, methionine, and lysine, and by 11% of valine and leucine. In addition, the integral score for the seeds of this variety was also the highest. The highest integral score in the studied varieties was determined for methionine – 33.0–38.9%, for isoleucine – 23.1–30.7, tryptophan, lysine, phenylalanine – 19.4–26.3, leucine and lysine – 16.6–26.3%. The major fatty acid in amaranth seeds is linoleic, the content of which in the seeds of the studied varieties varied significantly, from 2.03 to 2.95 g/100 g. The share of linolenic acid in the seeds ranged from 43.2 to 55.5%. The content of oleic acid varied from 1.60 to 1.33%, with the share of this acid being equal to 23.5–34.0%. The content of linolenic acid was the lowest, 0.01–0.03 g/100 g, with a share of 0.2–0.6% of the total fatty acids.
 Conclusions. Amaranth seeds have the highest percentage of carbohydrates that reach 63.1–68.2% in the studied varieties. The protein content varies from 16.1 to 24.7%. Among essential amino acids, the content of phenylalanine in seeds of the studied varieties was the highest, 985–1155 mg/100 g. The integral score of amaranth seeds for amino acids varied from lowest to highest in the following order: leucine, lysine, threonine, tryptophan, valine, phenylalanine, isoleucine and methionine. The content of fatty acids, varied, respectively: linolenic, stearic, palmitic, oleic and linoleic. According to indicators of the nitrogen-containing component and the content of fatty acids, the seeds of the ‘Kharkivskyi 1’ variety exceed the other studied amaranth varieties.

Fatty acid compositions of seeds of some proprietary safflower (Carthamus tinctorius L.) cultivars

Safflower, an important oil plant, has been cultivated for about 3000 years. Due to the fact that it is used as a raw material in many sectors, safflower has been examined in various studies. This study was carried out in the laboratories of the Department of Biosystem Engineering and the Central Laboratory Application and Research Center, Faculty of Agriculture, Bingol University between 2020 and 2021. In the study, the saturated fat contents of the seeds of four different registered safflower varieties (Balcı, Dinçer, Yektay, and Yenice) were determined. It was found that there were 19 different components in all safflower varieties. Oleic acid (20.03% to 34.41%) and Linoleic acid (39.79% to 53.70%) were found to be in the highest rates, and some fatty acids were detected in trace levels.
 Bangladesh J. Sci. Ind. Res. 57(3), 195-198, 2022

Fatty acid composition of seeds of pumpkin (Cucurbita) varieties cultivated mechanized in the conditions of the Nonchernozem zone of the Russian Federation

One of the most important factors for maintaining human health is a good nutrition of macro and micronutrients. Insufficient nutrition of essential nutrients leads to various disorders of the body. In recent years, more and more malnutrition has been observed, especially a deficiency of polyunsaturated fatty acids, vitamins and minerals. Of great interest is pumpkin seed oil, which is rich in linoleic acid. Linoleic acid belongs to the polyunsaturated fatty acids of the omega-6 family, which is not formed in the body and must be constantly supplied with food. Cultivation of pumpkin in the temperate zone is very important. This will provide the population with vegetable oil with high biological efficiency due to the content of linoleic acid. The fatty acid composition of pumpkin seeds is influenced by many factors: climatic data, varieties, agricultural practices, etc. Mechanized industrial crops of pumpkin are located mainly in the southern regions, due to the fact that this crop is thermophilic. In recent years, there has been a change in climate, in the temperate zone, the growing season has increased due to the earlier onset of spring and later autumn, the sum of active temperatures, etc. There is a certain tendency to increase the area occupied by this crop in the temperate zone. The correct selection of varieties and variety samples for mechanized cultivation becomes an urgent task. The experiments were carried out in the Moscow region. 16 varieties and variety samples were studied according to the standard method. A high oil content in the studied samples was revealed - The studied varieties and variety samples have a high oil content: from 33.6 to 54.6%. When studying the fatty acid composition, the highest content is represented by the essential polyunsaturated fatty linoleic acid up to 68.55% - in the Pivdenny variety.

Multiple caleosins have overlapping functions in oil accumulation and embryo development.

Caleosins are lipid droplet- and endoplasmic reticulum-associated proteins. To investigate their functions in oil accumulation, expression levels of caleosins in developing seeds of Arabidopsis thaliana were examined and four seed-expressed caleosins (CLO1, CLO2, CLO4, and CLO6) were identified. The four single mutants showed similar minor changes of fatty acid composition in seeds. Two double mutants (clo1 clo2 and clo1×clo2) demonstrated distinct changes of fatty acid composition, a 16-23% decrease of oil content, and a 10-13% decrease of seed weight. Moreover, a 40% decrease of oil content, further fatty acid changes, and misshapen membranes of smaller lipid droplets were found in seeds of quadruple CLO RNAi lines. Notably, ~40% of quadruple CLO RNAi T1 seeds failed to germinate, and deformed embryos and seedlings were also observed. Complementation experiments showed that CLO1 rescued the phenotype of clo1 clo2. Overexpression of CLO1 in seedlings and BY2 cells increased triacylglycerol content up to 73.6%. Transcriptome analysis of clo1 clo2 developing seeds showed that expression levels of some genes related to lipid, embryo development, calcium signaling, and stress responses were affected. Together, these results suggest that the major seed-expressed caleosins have overlapping functions in oil accumulation and show pleiotropic effects on embryo development.

The seed-specific transcription factor DPBF2 modulates the fatty acid composition in seeds.

Triacylglycerol (TAG), an ester derived from glycerol and three fatty acids (FAs), is synthesized during seed development and controlled by transcriptional regulation. We examined the mechanism regulating the FA composition of developing Arabidopsis thaliana seeds. The seed‐specific DC3 PROMOTER‐BINDING FACTOR2 (DPBF2) transcription factor was upregulated by LEAFY COTYLEDON2 (LEC2). DPBF2 showed transcriptional activity in yeast and localized to the nucleus in Arabidopsis protoplast cells. The Arabidopsis dpbf2‐1 homozygous T‐DNA mutant and transgenic lines overexpressing of DPBF2 using a seed‐specific phaseolin promoter in wild‐type (WT) Arabidopsis and in dpbf2‐1 showed similar FA composition profiles in their seeds. Their 18:2 and 20:1 FA contents were higher, but 18:1 and 18:3 contents were lower than that of WT. Transcript levels of FATTY ACID DESATURASE2 (FAD2), FAD3, LYSOPHOSPHATIDYLCHOLINE ACYLTRANSFERASE1 (LPCAT1), LPCAT2, PHOSPHATIDYLCHOLINE DIACYLGLYCEROL CHOLINEPHOSPHOTRANSFERASE (PDCT), and FATTY ACID ELONGASE 1 (FAE1) are increased in DPBF2‐overexpressing seeds. Besides, PDCT and FAE1 were upregulated by DPBF2, LEC1‐LIKE (L1L), and NUCLEAR FACTOR‐YC2 (NF‐YC2) transcriptional complex based on tobacco protoplast transcriptional activation assay. These results suggest that DPBF2 effectively modulates the expression of genes encoding FA desaturases, elongase, and acyl‐editing enzymes for modifying the unsaturated FA composition in seeds.

CHEMICAL COMPOSITION OF SEEDS OF PLANTS LUPINUS ANGUSTIFOLIUS L. AND LUPINUS ALBUS L. OF THE KALININGRAD REGION

The aim of the work was to study the chemical composition of seeds of plants Lupinus albus L., Lupinus angustifolius L., growing in the Kaliningrad region. Lupin is a promising crop due to the high content of biologically valuable protein in its seeds, as well as minerals, unsaturated fatty acids, water - and fat-soluble biologically active substances. The paper considers the amino acid, mineral, and fatty acid composition of seeds, presents data on the content of water-soluble vitamins in them, and shows the component composition of chloroform extracts of seeds.
 The total number of amino acids (47.72±0.37 and 38.655±0.32%, respectively) was found in the seeds of narrow-leaved and white lupine, and a high content of glutamic acid and asparagine was found. The macronutrient composition, which is dominated by potassium, phosphorus and calcium, was studied. Among the microelements of seeds, manganese, iron, zinc and silicon predominate. A particularly high content of manganese in white lupin seeds (192.14±1.67 mg per 100 g) was noted. Analysis of the fatty acid composition of lupin seed oils showed a high degree of unsaturation with a high content of oleic and linoleic acids. Both types of lupine contain thiamine, pyridoxine, and niacin, while white lupine seeds also contain Pantothenic and folic acids. Сhromatography-mass spectrometry analysis of the fraction isolated by chloroform from lupine seeds showed the presence of substances of the terpenes class (farnesene, neofitadiene, γ-tocopherol) and steriodic alcohols (campesterol, β-sitosterol).

The influence of agro-climatic conditions on the fatty acid composition of soybeans of the northern ecotype

In terms of biological value and quality, soy fat meets the standard of the Food and Agriculture Organization of the United Nations and the World Health Organization. The aim of the study was to identify agro-climatic factors that affect the fatty acid composition of soybean seeds of the northern ecotype and to determine the variety that most corresponds to the group of food fat quality. Field experiments were conducted in 2017–2019 in the Ryazan region at the experimental base of the Institute of Seed Production and Agricultural Technologies-a branch of the FGBNU FNAC VIM. Varieties and forms of soybeans of the northern ecotype – Light, Mageva, Okskaya and M-52-were selected as objects of research. The results of the study. The average yield of soybean seeds for three years of research was from 1.81 to 2.57 t / ha for varieties, the fat content in the seeds was 19.4–21.5 %, the total harvest was 357–548 kg/ha. The fat of soybean seeds of varieties and forms of the northern ecotype contained 11.36–11.43 % palmitic acid and significantly less oleic acid-7.43–11.27 %. While in traditional varieties, the values of these indicators were 9.75 % and 24.80 %, respectively. In conditions of sufficient moisture (2017), the predominance of saturated palmitic acid in the fatty acid composition of seeds was observed, and in dry years (2018–2019) – unsaturated fatty acids – oleic, linoleic and linolenic, their sum was 73 % in dry years, with sufficient moisture – 67 %. Better illumination of the upper tiers of plants contributed to the activation of the synthesis of unsaturated fatty acids. It was found that, according to the fatty acid composition, the Light soy variety is more close to the varieties of soy for food purposes.

Fatty acid composition in seeds of holoparasitic Orobanchaceae from the Caucasus region: Relation to species, climatic conditions and nutritional value

The specialization of parasitic plants from the Orobanchaceae family to the heterotrophic lifestyle caused several morphological, physiological and molecular changes. One of the adaptations to the parasitic lifestyle is the production of a large number of the smallest seeds in world flora, also called “dust-seeds”. Seeds of 34 holoparasitic species from the Cistanche, Orobanche, Phelipanche, and Phelypaea genera were collected in the Caucasus region (54 samples) and their fatty acid content and compositions analysed. Of these seeds, 28 were investigated for the first time, and 12 are endemic to the Caucasus (one of the most important biodiversity hotspots in the world). The influence of different hosts, populations, habitats, and climatic conditions on the fatty acid content and composition, as well as some connections of taxonomic classification are discussed. The fatty acid content in the species varied between 0.9 and 42.5%, and showed quantitative differences at generic and infrageneric levels, while displaying uniform fatty acid composition. Thirteen fatty acids were identified, of which nine were undescribed for Orobanchaceae. The fatty acid composition of the Orobanchaceae seeds represented a mixture of saturated fatty acids (SFAs) (average 7.8%) and unsaturated fatty acids (UFAs) (average 92.2%). The fatty acid content in the Orobanchaceae seeds was directly unrelated to taxonomy, while the n-6/n-3 fatty acid ratio supported the clear separation of the Orobanche and Phelipanche genera. Orobanchaceae seeds contained mainly linoleic and oleic acids, thus they could be a potential nutritional source of the unsaturated fatty acids. Additionally, the studies confirmed the hypothesis that the degree of seed oil fatty acid unsaturation increased in colder climatic conditions, especially for the Orobanche genus.

Profiling of seed fatty acid composition in 1025 Chinese soybean accessions from diverse ecoregions

The stability of soybean (Glycine max L. Merrill) oil is determined mainly by its fatty acid (FA) composition. We evaluated the FA composition of 1025 Chinese soybean accessions collected from diverse ecoregions and grown in multiple locations and years. We observed highly significant differences (P < 0.001) between accessions in palmitic acid (PA), stearic acid (SA), oleic acid (OA), linoleic acid (LA), and linolenic acid (LNA) contents. Growth year affected (P < 0.001) the abundance of all FAs except PA. The mean PA, SA, OA, LA, and LNA contents were 12.2%, 3.8%, 21.5%, 54.2%, and 8.3%, respectively. The geographical origin of the accession influenced seed FA composition, indicating that accessions originating in each ecoregion tend to have distinct FA composition. We observed significant positive correlations among the three locations and between the two years, suggesting the high heritability and stability of individual accessions across contrasting environments. We also observed a relatively high negative correlation between the contents of OA and both LA and LNA (r = −0.90 and −0.59, respectively, each significant at P < 0.001), providing a potential entry point for developing strains producing oil with higher OA and lower LA and LNA levels. These would be appropriate for specialized use in the food industry. Our results will be useful in breeding soybean with improved quality to meet human nutritional and industrial needs.

Targeted mutagenesis of BnTT8 homologs controls yellow seed coat development for effective oil production in Brassica napus L.

Yellow seed is a desirable trait with great potential for improving seed quality in Brassica crops. Unfortunately, no natural or induced yellow seed germplasms have been found in Brassica napus, an important oil crop, which likely reflects its genome complexity and the difficulty of the simultaneous random mutagenesis of multiple gene copies with functional redundancy. Here, we demonstrate the first application of CRISPR/Cas9 for creating yellow‐seeded mutants in rapeseed. The targeted mutations of the BnTT8 gene were stably transmitted to successive generations, and a range of homozygous mutants with loss‐of‐function alleles of the target genes were obtained for phenotyping. The yellow‐seeded phenotype could be recovered only in targeted mutants of both BnTT8 functional copies, indicating that the redundant roles of BnA09.TT8 and BnC09.TT8b are vital for seed colour. The BnTT8 double mutants produced seeds with elevated seed oil and protein content and altered fatty acid (FA) composition without any serious defects in the yield‐related traits, making it a valuable resource for rapeseed breeding programmes. Chemical staining and histological analysis showed that the targeted mutations of BnTT8 completely blocked the proanthocyanidin (PA)‐specific deposition in the seed coat. Further, transcriptomic profiling revealed that the targeted mutations of BnTT8 resulted in the broad suppression of phenylpropanoid/flavonoid biosynthesis genes, which indicated a much more complex molecular mechanism underlying seed colour formation in rapeseed than in Arabidopsis and other Brassica species. In addition, gene expression analysis revealed the possible mechanism through which BnTT8 altered the oil content and fatty acid composition in seeds.

Total Lipid Content and Fatty Acid Composition of Seeds of Some Wild Achillea Species

Total Lipid Content and Fatty Acid Composition of Seeds of Some Wild Achillea Species

Weathering the Cold: Modifying Membrane and Storage Fatty Acid Composition of Seeds to Improve Cold Germination Ability in Upland Cotton (Gossypium hirsutum L.)

Cotton is widely cultivated in temperate regions across the world and is often constrained by a short planting window that is bookended by low, suboptimal temperatures. With the growing interest in early season planting, improvements in the cold germination ability of cotton will be necessary to ensure the production stability of early planted crops. The importance of saturation levels of membrane and storage lipids in enhancing cold tolerance in plants, as well as improving cold germination ability in seeds have been widely researched in a range of plant species. While studies have shown that higher levels of unsaturated lipids can enhance cold germination ability and reduce seedling injury in other crops, similar efforts have been fairly limited in cotton. This review looks at the functional properties of membrane and storage lipids, and their role in membrane stability and reorganization during the early stages of germination. Additionally, the importance of storage lipid composition as an energy source to the growing embryo is described in the context of cellular energetics (i.e., fatty acid catabolism). Finally, perspectives in improving the cold germination of upland cotton by manipulating the fatty acid composition of both membrane and storage lipid content of seeds are presented.

Overexpression of Acyl-ACP Thioesterases, CpFatB4 and CpFatB5, Induce Distinct Gene Expression Reprogramming in Developing Seeds of Brassica napus.

We examined the substrate preference of Cuphea paucipetala acyl-ACP thioesterases, CpFatB4 and CpFatB5, and gene expression changes associated with the modification of lipid composition in the seed, using Brassica napus transgenic plants overexpressing CpFatB4 or CpFatB5 under the control of a seed-specific promoter. CpFatB4 seeds contained a higher level of total saturated fatty acid (FA) content, with 4.3 times increase in 16:0 palmitic acid, whereas CpFatB5 seeds showed approximately 3% accumulation of 10:0 and 12:0 medium-chain FAs, and a small increase in other saturated FAs, resulting in higher levels of total saturated FAs. RNA-Seq analysis using entire developing pods at 8, 25, and 45 days after flowering (DAF) showed up-regulation of genes for β-ketoacyl-acyl carrier protein synthase I/II, stearoyl-ACP desaturase, oleate desaturase, and linoleate desaturase, which could increase unsaturated FAs and possibly compensate for the increase in 16:0 palmitic acid at 45 DAF in CpFatB4 transgenic plants. In CpFatB5 transgenic plants, many putative chloroplast- or mitochondria-encoded genes were identified as differentially expressed. Our results report comprehensive gene expression changes induced by alterations of seed FA composition and reveal potential targets for further genetic modifications.

Phenotypic Characteristics and Fatty Acid Composition of Seeds from Different Herbaceous Peony Species Native to China.

Herbaceous peony has been widely cultivated in China due to its substantial ornamental and medicinal value. In the present study, the phenotypic characteristics, total fatty acid (FA) content, and nine FA compositions of herbaceous peony seeds from 14 populations belonging to six species and one subspecies were determined by normal test and gas chromatography/mass spectrometry (GC/MS). The results showed that the phenotypic characteristics of seeds varied dramatically among species. The concentrations of five major FAs in seed oils were as follows: linoleic acid (173.95-236.51 μg/mg), linolenic acid (227.82-302.71 μg/mg), oleic acid (135.32-208.81 μg/mg), stearic acid (6.52-11.7 μg/mg), and palmitic acid (30.67-47.64 μg/mg). Correlation analysis demonstrated that oleic acid had the highest partial correlation coefficient with total FAs and might be applied to develop a model of phenotypic characteristics. FAs were significantly influenced by the following environmental factors: latitude, elevation, and annual average temperature. Based on the FA levels in the seed oils, clustering analysis divided 14 populations into two clusters. It was found that the average contents of oleic acid, linoleic acid, and total FAs in cluster I (147.16 μg/mg, 200.31 μg/mg, and 671.24 μg/mg, respectively) were significantly lower than those in cluster II (196.65 μg/mg, 220.16 μg/mg, and 741.78 μg/mg, respectively). Cluster I was perfectly consistent with subsect. Foliolatae, while cluster II was in good agreement with subsect. Dissectifoliae. Therefore, the FA composition of wild herbaceous peony seed oil might be used as a chemotaxonomic marker.

The phytochemical variability of fatty acids in basil seeds (Ocimum basilicum L.) affected by genotype and geographical differences.

Basil (Ocimum basilicum) from the Lamiaceae family is among the most important medicinal plants, and its seed fatty acid (FA) composition and quantity affects its nutritional and health values. It was hypothesized basil species and geographical properties significantly affect seed FA composition and quantity, which has not been previously investigated, to our knowledge. The collected seeds of the 18 basil populations were planted in a farmer's field, and the seed saturated (palmitic and stearic) and unsaturated (oleic, linoleic, and linolenic) FA were determined. Shiraz1 (14.7%) and Mobarakeh (5.1%) had the highest and the least rates of total FA, respectively. The populations were significantly different in terms of saturated FA ranging from 10.73% (Ardestan) to 13.51% (Bid Zard). However, the seed unsaturated FA (expect linoleic acid) were not significantly different from each other (average = 87.27%). Basil species and geographical properties significantly affected basil saturated FA and just unsaturated linoleic acid.

Seed-Specific Expression of AtLEC1 Increased Oil Content and Altered Fatty Acid Composition in Seeds of Peanut (Arachis hypogaea L.).

Peanut (Arachis hypogaea L.) is one of the major oil crops and is the fifth largest source of plant oils in the world. Numerous genes participate in regulating the biosynthesis and accumulation of the storage lipids in seeds or other reservoir organs, among which several transcription factors, such as LEAFY COTYLEDON1 (AtLEC1), LEC2, and WRINKLED1 (WRI1), involved in embryo development also control the lipid reservoir in seeds. In this study, the AtLEC1 gene was transferred into the peanut genome and expressed in a seed-specific manner driven by the NapinA full-length promoter or its truncated 230-bp promoter. Four homozygous transgenic lines, two lines with the longer promoter and the other two with the truncated one, were selected for further analysis. The AtLEC1 mRNA level and the corresponding protein accumulation in different transgenic overexpression lines were altered, and the transgenic plants grew and developed normally without any detrimental effects on major agronomic traits. In the developing seeds of transgenic peanuts, the mRNA levels of a series of genes were upregulated. These genes are associated with fatty acid (FA) biosynthesis and lipid accumulation. The former set of genes included the homomeric ACCase A (AhACC II), the BC subunit of heteromeric ACCase (AhBC4), ketoacyl-ACP synthetase (AhKAS II), and stearoyl-ACP desaturase (AhSAD), while the latter ones were the diacylglycerol acyltransferases and oleosins (AhDGAT1, AhDGAT2, AhOle1, AhOle2, and AhOle3). The oil content and seed weight increased by 4.42–15.89% and 11.1–22.2%, respectively, and the levels of major FA components including stearic acid, oleic acid, and linoleic acid changed significantly in all different lines.

Effect of high night temperature on storage lipids and transcriptome changes in developing seeds of oilseed rape.

Global warming causes a faster increase of night temperature than of day temperature in tropical and subtropical zones. Little is known about the effect of high night temperature on storage lipids and transcriptome changes in oilseed rape. This study compared the total fatty acids and fatty acid compositions in seeds of two oilseed rape cultivars between high and low night temperatures. Their transcriptome profiles were also analyzed. High night temperature significantly affected the total fatty acids and fatty acid compositions in seeds of both low and high oil content cultivars, namely Jiuer-13 and Zheyou-50, thereby resulting in 18.9% and 13.7% total fatty acid reductions, respectively. In particular, high night temperature decreased the relative proportions of C18:0 and C18:1 but increased the proportions of C18:2 and C18:3 in both cultivars. In-depth analysis of transcriptome profiles revealed that high night temperature up-regulated gibberellin signaling during the night-time. This up-regulation was associated with the active expression of genes involved in fatty acid catabolism, such as those in β-oxidation and glyoxylate metabolism pathways. Although the effect of temperature on plant lipids has been previously examined, the present study is the first to focus on night temperature and its effect on the fatty acid composition in seeds.

Fatty Acid and Associated Gene Expression Analyses of Three Tree Peony Species Reveal Key Genes for α-Linolenic Acid Synthesis in Seeds.

The increasing demand for healthy edible oil has generated the need to identify promising oil crops. Tree peony (Paeonia section Moutan DC.) is a woody oil crop with α-linolenic acid (ALA) contributing for 45% of the total fatty acid (FA) content in seeds. Molecular and genetic differences that contribute to varied FA content and composition among the wild peony species are, however, poorly understood. Analyses of FA content and composition during seed development in three tree peony species (Paeonia rockii, P. potaninii, and P. lutea) showed varied FA content among them with highest in P. rockii, followed by P. potaninii, and P. lutea. Total FA content among these species increased with seed development and reached its maximum in its final stage. Seed FA composition analysis of the three species also revealed that ALA (C18:3) was the most abundant, followed by oleic (C18:1) and linoleic (C18:2) acids. Additionally, quantitative real-time RT-PCR analyses of 10 key seed oil synthesis genes in the three tree peony species revealed that FAD3, FAD2, β-PDHC, LPAAT, and Oleosin gene expression levels positively correlate with total FA content and rate of accumulation. Specifically, the abundance of FAD3 transcripts in P. rockii compared with P. potaninii, and P. lutea suggests that FAD3 might play an important role in synthesis of ALA via phosphatidylcholine-derived pathway. Overall, comparative analyses of FA content and composition in three different peony species revealed a correlation between efficient lipid accumulation and lipid gene expression during seed development. Further characterization and metabolic engineering of these key genes from peonies will allow for subsequent improvement of tree peony oil quality and production.