Source Of Tocopherols Research Articles

Natural variation in tocopherols, B vitamins, and isoflavones in seeds of 13 Korean conventional soybean varieties

Soybean seeds are excellent sources of tocopherols, B vitamins, and isoflavones, which are well known for their health benefits. This study investigated the influence of environment and genotype on these constituents across 13 Korean soybean varieties cultivated in three locations during the 2017–2019 growing seasons. Statistical analyses, employing both univariate and multivariate methods, revealed significant impacts of genetic and environmental factors on the composition of tocopherols, B vitamins, and isoflavones. Through permutational univariate analysis of variance, the primary contributors to each measured component were identified. Genotype strongly influenced the levels of β- and δ-tocopherols, whereas the interaction between location and year predominantly affected α- and γ-tocopherols. Vitamin B1 content was predominantly determined by genotype, whereas B3 and B6 were influenced by annual variations. Vitamin B2 level was primarily affected by the interplay between environmental and genotypic effects. Genotype had a significant effect on isoflavone components, with the exception of daidzein. Furthermore, early maturing varieties and those with black seed coats exhibited low levels of isoflavone components and total isoflavones, suggesting a relationship between maturity group and seed coat color in isoflavone variation. These findings can be used as reference values for compositional equivalence assessment of genetically modified soybeans.

Nutrient and bioactive compounds from Neltuma spp. seeds

AbstractIn the search for compounds with nutritional and functional value, seeds from several Neltuma species were examined for lipid, protein and phenolic components. Lipid contents ranged between 9.3 and 12.5 g/100 g (seed dry weight), and showed both oleic and linoleic acids predominating largely. Lipids were also a good source of tocopherols (170–603 mg total tocopherols/kg). Proteins accounted for 14.7–35.5 g/100 g seed. Essential amino acids (EAA) comprised 26.1%–40.2% of the total AA content. Based on the EAA score, proteins from all the species analyzed were deficient in leucine, isoleucine and valine, but could meet requirements for histidine, threonine, phenylalanine, tyrosine, and lysine. The qualitative patterns of phenolic compounds were similar each other (predominance of flavonoids, particularly apigenin derivatives). Keeping in mind the examined chemical components, Neltuma seeds have potential value as a source of healthy macronutrients and bioactive compounds.

Reduction of Saturated Fat in Dark Chocolate using Sacha Inchi (Plukenetia volubilis) Oil Oleogel

This research studied the effectiveness of Sacha Inchi Oil Oleogel (SIOO) as a partial replacement for saturated fat in dark chocolate. Sacha inchi (Plukenetia volubilis) oil is high in polyunsaturated fatty acids (α-linolenic and linoleic acids) and a good source of tocopherols. This study prepared oleogels using sacha inchi oil as a base oil and food-grade beeswax as an oleogelator. Different percentages of SIOO (1%, 2.5% and 5.0%) were added in the dark chocolate. Dark chocolate without SIOO was used as a control. Fatty acid profile, total polyphenols, antioxidant activity and sensory evaluation of the formulated dark chocolates with SIOO were investigated. The incorporation of SIOO significantly (p<0.05) lowered the saturated fat and increased the polyunsaturated fatty acids in dark chocolate samples. This study also showed that the total polyphenols and antioxidant activity of dark chocolates enriched with 2.5 and 5.0% SIOO were significantly higher (p<0.05) than the other chocolate samples. Sensory evaluation showed that control and dark chocolates added with SIOO (1% and 2.5%) received similar scores for all sensory attributes. However, the highest concentration of SIOO decreased significantly (p<0.05) the scores for the taste and overall acceptability of dark chocolate. Therefore, the enrichment of sacha inchi oil oleogel as a functional ingredient could reduce the saturated fat and increase the polyunsaturated fatty acids and antioxidant activity of the formulated dark chocolate, which is well-accepted by consumers.

Genome-wide scan for oil quality reveals a coregulation mechanism of tocopherols and fatty acids in soybean seeds

Tocopherols (vitamin E) play essential roles in human health because of their antioxidant activity, and plant-derived oils are the richest sources of tocopherols in the human diet. Although soybean (Glycine max) is one of the main sources of plant-derived oil and tocopherol in the world, the relationship between tocopherol and oil in soybean seeds remains unclear. Here, we focus on dissecting tocopherol metabolism with the long-term goal of increasing α-tocopherol content and soybean oil quality. We first collected tocopherol and fatty acid profiles in a soybean population (>800 soybean accessions) and found that tocopherol content increased during soybean domestication. A strong positive correlation between tocopherol and oil content was also detected. Five tocopherol pathway–related loci were identified using a metabolite genome-wide association study strategy. Genetic variations in three tocopherol pathway genes were responsible for total tocopherol content and composition in the soybean population through effects on enzyme activity, mainly caused by non-conserved amino acid substitution or changes in gene transcription level. Moreover, the fatty acid regulatory transcription factor GmZF351 directly activated tocopherol pathway gene expression, increasing both fatty acid and tocopherol contents in soybean seeds. Our study reveals the functional differentiation of tocopherol pathway genes in soybean populations and provides a framework for development of new soybean varieties with high α-tocopherol content and oil quality in seeds.

Regulatory Effects of Thai Rice By-Product Extracts from Oryza sativa L. cv. Bue Bang 3 CMU and Bue Bang 4 CMU on Melanin Production, Nitric Oxide Secretion, and Steroid 5α-Reductase Inhibition.

Alopecia and gray hair are common hair abnormalities affecting physical appearance and causing psychological problems. Chemical treatments partially restore hair disorders but have distressing side effects. Bioactive plant compounds constitute promising sources of potential medicinal substances instead of chemical agents, producing high side effects. In this study, we focused on the waste of local rice cultivars: Bue Bang 3 CMU (BB3CMU) and Bue Bang 4 CMU (BB4CMU) from the north of Thailand. The rice bran oil (RBO), defatted rice bran extract (DFRB), and rice husk (H) were determined for in vitro hair revitalization in melanin production, nitric oxide (NO) secretion, and steroid 5α-reductase inhibition. The results indicated that BB4CMU-RBO with high contents of iron, zinc, and free fatty acids showed a comparable induction of melanin production on melanocytes (130.18 ± 9.13% of control) to the standard drug theophylline with no significant difference (p > 0.05). This promising melanin induction could be related to activating the NO secretion pathway, with the NO secretion level at 1.43 ± 0.05 µM. In addition, BB4CMU-RBO illustrated a significant inhibitory effect on both steroid 5α-reductase genes (SRD5A) type 1 and type 2, which relates to its primary source of tocopherols. Hence, rice bran oil from the Thai rice variety BB4CMU could be applied as a promising hair revitalizing candidate, from natural resources, to help promote hair growth and re-pigmentation effects.

A Comprehensive Review On Pistacia Khinjuk Well-Known Medicinal Plant

Pistacia, a genus of flowering plants from the family Anacardiaceae, contains about twenty species, among them five are more popular including P. vera, P. atlantica, P. terebinthus, P. khinjuk, and P. lentiscus. Different parts of these species have been used in traditional medicine for various purposes like tonic, aphrodisiac, antiseptic, antihypertensive and management of dental, gastrointestinal, liver, urinary tract and respiratory tract disorders.Pistacia khinjuk Stoks (P. khinjuk) is an evergreen shrub or tree of the family Anarcadiaceae. This specie is native to Turkey, Syria, Iraq, Iran, Egypt, Afghanistan, India and Pakistan.P. khinjuk used as tonic and expectorant, it has been used in cough, fever and asthma.Few investigations have been reported the effect of different crude and isolated compound extracts of P. khinjuk on different diseases such as antidiabetic, antitumor, anti-cholinesterase, antimicrobial and antifungal activity. The oil of P. khinjuk kernel is valuable oil being used in the pharmaceutical industry. It’s mainly composed of oleic, linolenic, palmitic, linolenic, behenic,lauric, myristic and arachidic acid. In addition, oil is considered a valuable source of tocopherols and tocotrienols because the tocols content reported for this oil is much higher than that of common oils. The aim of the present review is to explore the traditional and modern knowledge including the botanical description, ethnomedicinal claims, pharmacognostic parameters, phytochemicals and pharmacological potential of P. khinjuk. The comprehensive literature and relevant information regarding the plant were gathered through electronic databases including Google Scholar, Pub Med, Science direct, online open access databases and books from the college library. The review represents consolidated summary in all aspects of plant with a special emphasis on reported phytochemicals isolated from plant and their therapeutic potential. The rearranged data in the form of a single review will be essential in providing updated knowledge to the readers regarding the plant and it will act as a baseline for future exploration of P. khinjukin terms of its phytochemistry and pharmacology

Effect of Overexpression of γ-Tocopherol Methyltransferase on α-Tocopherol and Fatty Acid Accumulation and Tolerance to Salt Stress during Seed Germination in Brassica napus L.

Rapeseed (Brassica napus L.) is an important oil crop and a major source of tocopherols, also known as vitamin E, in human nutrition. Enhancing the quality and composition of fatty acids (FAs) and tocopherols in seeds has long been a target for rapeseed breeding. The gene γ-Tocopherol methyltransferase (γ-TMT) encodes an enzyme catalysing the conversion of γ-tocopherol to α-tocopherol, which has the highest biological activity. However, the genetic basis of γ-TMT in B. napus seeds remains unclear. In the present study, BnaC02.TMT.a, one paralogue of Brassica napus γ-TMT, was isolated from the B. napus cultivar "Zhongshuang11" by nested PCR, and two homozygous transgenic overexpression lines were further characterised. Our results demonstrated that the overexpression of BnaC02.TMT.a mediated an increase in the α- and total tocopherol content in transgenic B. napus seeds. Interestingly, the FA composition was also altered in the transgenic plants; a reduction in the levels of oleic acid and an increase in the levels of linoleic acid and linolenic acid were observed. Consistently, BnaC02.TMT.a promoted the expression of BnFAD2 and BnFAD3, which are involved in the biosynthesis of polyunsaturated fatty acids during seed development. In addition, BnaC02.TMT.a enhanced the tolerance to salt stress by scavenging reactive oxygen species (ROS) during seed germination in B. napus. Our results suggest that BnaC02.TMT.a could affect the tocopherol content and FA composition and play a positive role in regulating the rapeseed response to salt stress by modulating the ROS scavenging system. This study broadens our understanding of the function of the Bnγ-TMT gene and provides a novel strategy for genetic engineering in rapeseed breeding.

Chemical composition and thermal properties of Tunisian pecan nut [Carya illinoinensis (Wangenh.) K. Koch] oils

An investigation on fatty acid, triacylglycerol, tocopherol, and xanthophyll contents and thermal properties of pecan (Carya illinoinensis) kernel oils from two cultivars was carried out. The main fatty acids were oleic acid, followed by linoleic and palmitic acids. The predominant triacylglycerols were OOL, OOO, and OLL (where O stands for oleoyl and L for linoleoyl). Pecan kernel oil is a rich source of tocopherols, mainly γ-tocopherol. Two xanthophylls (lutein and zeaxanthin) were investigated, and lutein was found to be the major one. Thermal behavior was studied by differential scanning calorimetry (DSC). Pecan nut oil displayed melting and crystallization transitions at low-temperature zones. The difference between DSC parameter values provides a path for distinguishing among cultivars. These data promote pecan kernel oil as a potential source of bioactive compounds with nutraceutical properties (monounsaturated fatty acids, tocopherols, and xanthophylls) and reveal, for the first time, the thermal properties of Carya illinoinensis oil.

Seven underutilized species of the Fabaceae family with high potential for industrial application as alternative sources of oil and lipophilic bioactive compounds

Fabaceae is the third largest family in the plant world, mainly considered a source of relatively valuable plant protein and a rather poor source of oil. The present study shows that several legume species (Bauhinia purpurea, Phanera vahlii, Butea monosperma, Caesalpinia crista, Gliricidia sepium, Mimosa pudica, Millettia pinnata) can be also considered as an alternative source of oil. The oil yield in studied species (19–36%) was similar or even higher than in soybean (Glycine max), the most known representant of the Fabaceae family. Palmitic, stearic, oleic, and linoleic acids constitute 87–99% of detected fatty acids with predomination of unsaturated (62–82%). All obtained oils were rich sources of tocopherols (79–187 mg/100 g oil), mainly α (five species) and γ (two species) homologues. With the exception of M. pinnata, where Δ5-stigmasterol (25%) and α-amyrin (26%) were the main phytosterols, β-sitosterol, Δ5-stigmasterol and campesterol constituted 51–96% of total phytosterols with a predomination of β-sitosterol (36–64%). The total carotenoid and phytosterol contents in studied Fabaceae species were in the range 0.6–8.9 and 175–622 mg/100 g oil, respectively. The present study demonstrated that several legume seeds could be considered a valuable source of oil and lipophilic bioactive compounds.

Comparative Evaluation of the Nutrients, Phytochemicals, and Antioxidant Activity of Two Hempseed Oils and Their Byproducts after Cold Pressing.

Recently, there has been a growing interest in the recovery of agri-food waste within the circular economy perspective. In this study, the nutritional, phytochemical, and biological features of the cold-pressed hempseed oil (HSO) and hempseed meal (HSM) of two industrial hemp varieties (USO 31 and Futura 75, THC ≤ 0.2%) were evaluated. The HSOs showed a high total phenols and flavonoid content, which were confirmed by LC-DAD-ESI-MS analysis, with rutin as the most abundant compound (56.93–77.89 µg/100 FW). They also proved to be a rich source of tocopherols (81.69–101.45 mg/100 g FW) and of a well-balanced ω-6 to ω-3 fatty acid ratio (3:1) with USO 31, which showed the best phytochemical profile and consequently the best antioxidant activity (about two times higher than Futura 75). The HSMs still retained part of the phytochemicals identified in the HSOs (polyphenols, tocopherols, and the preserved ω-6/ω-3 fatty acids ratio) and a modest antioxidant activity. Furthermore, they showed a very interesting nutritional profile, which was very rich in proteins (29.88–31.44 g/100 g FW), crude fibers (18.39–19.67 g/100 g), and essential and non-essential amino acids. Finally, only a restrained amount of anti-nutritional factors (trypsin inhibitors, phytic acid, and condensed tannins) was found, suggesting a promising re-use of these byproducts in the nutraceutical field.

Valorization of soybean oil residue through advanced technology of graphene oxide modified membranes for tocopherol recovery

AbstractSoybean oil deodourization distillate (SODD) is a source of tocopherols used to produce vitamin E, in which α‐tocopherol is the isomer with higher biological activity and value‐added for the food industry. Hence, the aim of the present study was to modify the membrane surface with sulphonic groups, polyethyleneimine, and graphene oxide nanoparticles functionalized with tannic acid to recover SODD α‐tocopherol. First, the SODD saponification step was conducted followed by a liquid–liquid separation, which performed a pre‐concentration of α‐tocopherol approximately 28 times. The unsaponifiable material was dried and diluted in hexane, obtaining the feed solution for the membrane filtration processes. HPLC‐UV/DAD analysis showed that the modified membrane containing 1.12 mg of graphene oxide and 4.50 mg of tannic acid (M3) allowed to recover 82.00% of α‐tocopherol in the concentrate (14.16 wt.% of α‐tocopherol). From the characterizations of the modified membrane, it was observed that M3 presented hydrophobic properties and was able to be reused in two filtration cycles with a 64.39% flow recovery rate and a 71.96% recovery of α‐tocopherol. The results showed that the membrane modification with graphene oxide is a compelling methodology with low energy consumption and is eco‐friendly for the recovery and purification of α‐tocopherol from SODD.

Antioxidation, Anti-Inflammation, and Regulation of SRD5A Gene Expression of Oryza sativa cv. Bue Bang 3 CMU Husk and Bran Extracts as Androgenetic Alopecia Molecular Treatment Substances.

Androgenetic alopecia (AGA), a hair loss disorder, is a genetic predisposition to sensitive androgens, inflammation, and oxidative stress. Unfortunately, current treatments with synthetic medicines contain a restricted mechanism along with side effects, whereas the bioactive constituents of plant extracts are multifunctional, with fewer side effects. The massive amounts of rice husk and bran are agricultural wastes that may cause pollution and environmental problems. Owing to these rationales, the local rice variety, Bue Bang 3 CMU (BB3CMU), which is grown in northern Thailand, was evaluated for the valuable utilization of rice by-products, husk (BB3CMU-H) and bran (BB3CMU-RB) extracts, for AGA treatment regarding antioxidant, anti-inflammatory, anti-androgenic activities, and the characterization of bioactive compounds. Our study verified that BB3CMU-H had the highest level of polyphenols, contributing to its greater antioxidant activity. Conversely, BB3CMU-RB was the predominant source of tocopherols, resulting in better anti-androgenic activities regarding the downregulation of steroid 5α-reductase genes (SRD5A). Notably, anti-inflammation via the attenuation of nitric oxide productions was observed in BB3CMU-H (0.06 ± 0.13 μM) and BB3CMU-RB (0.13 ± 0.01 μM), which were significantly comparable to diclofenac sodium salt (0.13 ± 0.19 μM). Therefore, the combination of BB3CMU-H and BB3CMU-RB could be utilized in cosmeceutical and pharmaceutical applications for AGA patients.

Soybean Callus—A Potential Source of Tocopherols

In vitro cultures have been used as an effective means to achieve a high level of secondary metabolites in various plants, including soy. In this study, the contents of α-, γ-, and δ- tocopherol were quantified in soybean callus, and their amounts were compared to those of soybeans cultivated using the conventional tillage system with three weed controls (respectively without herbicide and with two variants of herbicide). Soybean callus was produced using Murashige and Skoog 1962 (MS) medium supplemented with 0.1 mg/L 6-Benzylaminopurine (BAP) and 0. 1 mg/L Thidiazuron (TDZ). The highest amount of fresh callus was obtained from soybeans from the conventional tillage system with second weed control (S-metolachlor 960 g/L, imazamox 40 g/L, and propaquizafop 100 g/L) respectively 13,652.4 ± 1177.62 mg. The analyzed tocopherols were in much higher content in soy dry callus than the soybean seeds (5.63 µg/g compared with the 0.35 α-toco in soybean, 47.57 µg/g compared with 18.71 µg/g γ-toco or, 5.56 µg/g compared with 1.74 µg/g β-toco). The highest content of the three analyzed tocopherols was γ -tocopherol, both in callus and soybeans. Furthermore, the data showed that herbicides used in soybean culture significantly influenced both the in vitro callus production and the tocopherol callus content (p ˂ 0.05). Altogether, soybean callus can be an important source of tocopherols, and herbicides significantly influence in vitro callus production and the tocopherol callus content.

Fruit tree leaves as valuable new source of tocopherol and tocotrienol compounds.

Nowadays it is highly important to find new, cheap and widely available sources of tocopherol and tocotrienol compounds, and leaves are promising unconventional sources. The main goal of this study was to extend the currently limited knowledge concerning tocopherol and tocotrienol isomers composition determined using ultra-high performance liquid chromatography with fluorescence detection analysis for various fruit tree leaves such as apple, pear, quince, apricot, peach, plum, sour cherry and sweet cherry. The leaves were collected 2 weeks after tree blooming and after fruit collection. Tocopherol and tocotrienol isomers were identified and quantified for the first time in all fruit tree leaves. The total tocopherol content ranged from 203.34 to 260.86 μg g-1 dry weight for spring leaves and from 23.83 to 235.62 μg g-1 dry weight for autumn leaves and consisted mainly of α-tocopherol. The rest of the isomers of tocopherol and tocotrienols were also found, but in trace amounts. A significantly lower content of tocopherols and tocotrienols was detected in leaves after autumn collection of fruits compared to leaves collected after blooming. Among the analyzed leaves, time collected and species were significantly more important than their cultivars. Regarding quantification analysis, apricot > peach > > plums > apples leaves were identified as the best sources of tocopherols, and sweet and sour cherry leaves exhibited a lower content. Fruit tree leaves are a novel significant source and good material for isolation of α-tocopherol for application in cosmetics, pharmaceuticals or in the food industry - for example, production of beverages or other functional foods. © 2021 Society of Chemical Industry.

Chemical characterization of carob seeds (Ceratonia siliqua L.) and use of different extraction techniques to promote its bioactivity

Nowadays, the use of carob (Ceratonia siliqua L.) is reduced to its seeds. In fact, the food additive E410, locust bean gum, is obtained from its endosperm. However, the available information regarding the bioactive potential of carob seeds is limited and, often, with poorly established terminologies, not allowing the reader to know if the studied samples included seedless or seeded samples. So, the present study intended to carry out a chemical characterization of carob seeds focused on their bioactive compounds and test their bioactive properties. Carob seeds proved to be a source of tocopherols and organic acids, including phenolic compounds. Its antioxidant potential was demonstrated in vitro, as well as its antimicrobial capacity. This work proves that carob seeds have other functions in addition to those associated with E410. Thus, another potential can be given to the locust bean seed, namely the function of food preservative.

Occurrence of Tocols in Foods: An Updated Shot of Current Databases

Tocols are present in various foods, mostly in fruits and in plant seeds. Edible oils are the most important natural dietary sources of tocopherols and tocotrienols, collectively known as tocols. Tocopherols and tocotrienols are considered beneficial for their antioxidant effect which impacts on prevention of different health conditions. This perspective is addressed to give an updated picture of the tocol occurrence in foods. Moreover, the current state of the art of tocols in updated databases is explored and commented outlining their importance and future trends.

Acorn Oil: Chemistry and Functionality

Acorn oil has been receiving increasing attention due to its nutritional potentials. However, its application as a novel food ingredient has not yet been fully explored. This paper summarizes chemical composition, extraction methods, potential health benefits, and current applications of acorn oil, with the aim of providing suggestions for its exploitation. Acorn oil is an excellent source of essential fatty acids (oleic, linoleic, α-linolenic, and palmitic acids). Acorns are a rich source of tocopherols, with γ-tocopherol being the most abundant. It also contains various bioactive compounds such as polyphenols and sterols (mainly β-sitosterol). Diets enriched with acorn oil can be beneficial in preventing cardiovascular disease (CVD), cancer, and type 2 diabetes as well as offer antioxidant activity. Further studies should focus on producing better quality acorn oil such as the application of more innovative and optimized techniques that can increase its health benefits and hence utilization.

Impacts of Protease Treatment on the Contents of Tocopherols and B Vitamins in Peanuts

This study investigated the changes of tocopherols and B vitamins in raw peanuts as a result of protease treatment which was used to reduce peanut allergens. Raw peanut kernels were treated with Alcalase, bromelain, Neutrase and papain separately at different concentrations, vacuum dried, and then ground into paste. The paste was defatted using hexane containing 0.02% BHT to obtained crude oil and defatted peanut flour which were used for tocopherol and B-vitamin analysis, respectively. The protease treatment significantly reduced the contents of all tocopherols and B-vitamins in the peanuts in enzyme concentration-dependent manner (P<0.0001). The highest losses of α-, γ-, and δ-tocopherols were 60.87 %, 40.60 % and 36.89 %, respectively, while the maximum losses of vitamins B1, B2, B3 and B6 were 63.29 %, 44.83 %, 40.56 % and 49.59 %, respectively. Among tocopherols, α-tocopherol was the most affected while δ-tocopherol was the least affected. Among B-vitamins, B1 was the most affected and B3 the least affected. This study demonstrated that although the protease treatment approach (including enzyme treatment and drying) for peanut allergen reduction resulted in different degrees of losses in tocopherols and B vitamins in raw peanuts, the enzyme treated peanuts is still a good source of tocopherols and vitamin B3 comparing to most cooked legumes and vegetable.

Differential accumulation of tocochromanols in photosynthetic and non-photosynthetic tissues of strawberry plants subjected to reiterated water deficit

Tocochromanols are a group of lipid-soluble antioxidants that include tocopherols, tocotrienols and plastochromanol-8. Here, we examined a putative differential accumulation of tocochromanols in photosynthetic and non-photosynthetic tissues (including leaves and whole fruits) of strawberry (Fragaria x ananassa cv. Albion) plants and evaluated their endogenous variations in response to a reiterated water deficit during a vegetative (non-productive) and a fruiting (productive) period. In addition, we evaluated the concentration of tocochromanols in achenes (true fruits) and flesh of strawberries (whole fruits) at the white and full-red stages both under optimal and stress conditions. Results showed that leaves mainly accumulated α-tocopherol, with plastochromanol-8 and γ-tocopherol being present at low amounts. In contrast, whole fruits did not accumulate plastochromanol-8, γ-tocopherol being the major tocochromanol in the achenes (true fruit) and α-tocopherol in the flesh. While α-tocopherol content in leaves increased up to seven-fold after 12 weeks of stress during the fruiting period, it kept unaltered during the vegetative period. Neither plastochromanol-8 nor γ-tocopherol contents increased in leaves of stressed plants. During the fruiting period, γ-tocopherol content increased in whole fruits of stressed plants (most of it being accumulated in the achenes). Among the compounds examined, the flesh of strawberries accumulated α-tocopherol only, both at the white and full-red stages. It is concluded that (i) α-tocopherol is the major tocochromanol in leaves, while γ-tocopherol is the major tocochromanol in achenes (ii) reiterated water deficit promotes the accumulation of α-tocopherol in leaves and γ-tocopherol in fruits, (iii) α-tocopherol not only accumulates in photosynthetic tissues (leaves and whole fruits at green stages), but also in non-photosynthetic tissues (flesh of whole fruits at the white and full-red stages), and (iv) achenes (true fruits) of strawberry plants are an extraordinary rich source of tocopherols.

Identification of quantitative trait loci for increased \u03b1-tocopherol biosynthesis in wild soybean using a high-density genetic map

BackgroundSoybean is one of the most important crop sources of tocopherols (Toc). However, the content of α-Toc, an isoform with the highest vitamin E activity in humans, is low in most cultivars. With the aim of broadening genetic variability, we performed quantitative trait locus (QTL) analysis for a high seed α-Toc trait detected in a wild soybean and characterized the sequence polymorphisms and expression profiles of γ-tocopherol methyltransferase (γ-TMT) genes as potential candidates.ResultsA recombinant inbred line population was developed from a cross between the low α-Toc breeding line TK780 and the high α-Toc wild accession B04009. The α-Toc content in seeds correlated strongly with the ratio of α-Toc to γ-Toc contents. QTL analysis using a high-density map constructed with 7710 single nucleotide polymorphisms (SNPs) generated by restriction site-associated DNA sequencing detected six QTLs involved in α-Toc biosynthesis. Of these, three in chromosomes (Chr) 9, 11, and 12 produced consistent effects during a 2-year trial. B04009 allele at QTLs in Chr9 and Chr12 and TK780 allele at the QTL in Chr11 each promoted the conversion of γ-Toc to α-Toc, which elevated the seed α-Toc content. SNPs and indels were detected between the parents in three γ-TMT genes (γ-TMT1, γ-TMT2, and γ-TMT3) co-located in the QTLs in Chr9 and Chr12, of which some existed in the cis-regulatory elements associated with seed development and functions. In immature cotyledons, γ-TMT3 was expressed at higher levels in B04009 than TK780, irrespective of two thermal conditions tested, whereas the expression of γ-TMT2 was markedly upregulated under higher temperatures, particularly in B04009.ConclusionsWe identified QTLs consistently controlling α-Toc biosynthesis in wild soybean seeds in 2-year trials. The QTL on Chr9 had been previously identified in soybean, whereas the QTLs on Chr11 and Chr12 were novel. Further molecular dissections and characterization of the QTLs may facilitate the use of high α-Toc alleles from wild soybean in soybean breeding and an understanding of the molecular mechanisms underlying α-Toc biosynthesis in soybean seeds.