Se Biofortification Research Articles

Effect of Rice Grain (Oryza sativa L.) Enrichment with Selenium on Foliar Leaf Gas Exchanges and Accumulation of Nutrients.

An agronomic itinerary for Se biofortification of two rice cultivars (Ariete and Ceres) through foliar fertilization with sodium selenate and sodium selenite with different concentrations (25, 50, 75 and 100 g Se.ha−1), was implemented in experimental fields. The selenium toxicity threshold was not exceeded, as shown by the eco-physiological data obtained through leaf gas exchanges. The highest Se enrichment in paddy grains was obtained with selenite for both cultivars, especially at the highest doses, i.e., 75 and 100 g Se.ha−1, with approximately a 5.0-fold increase compared with control values. In paddy grains, Zn was the most affected element by the treatments with Se with decreases up to 54%. When comparing the losses between rough and polished grains regardless of the cultivars, Se species and concentrations, it was observed that only Cu, Mg and Zn exhibited losses <50%. The remaining elements generally had losses >70%. The loss of Se is more pronounced in Ceres cultivar than in Ariete but rarely exceeds 50%. The analysis by µ-EDXRF showed that, in Ariete cultivar, Se is mostly homogeneously distributed in the grain regardless of any treatments, while in Ceres cultivar, the Se distribution seems to favor accumulation in the periphery, perhaps in the bran.

Selenium bioavailability in soil-wheat system and its dominant influential factors: A field study in Shaanxi province, China

Selenium (Se) content of crops depends on the local soil Se content and/or its bioavailability, and identifying the influence factors of soil Se bioavailability is a significant basis for adopting targeted agronomic measures to improve the Se nutritional status of humans. In this study, the main wheat–producing region in Shaanxi province with similar parent material and climate conditions was selected as the study area. The total Se contents of 602 soil samples and their corresponding wheat grains were determined, and the distribution characteristics of soil Se bioavailability and its dominant influential factors were investigated. Results showed that the total Se content ranged from 0.02 mg/kg to 1.67 mg/kg (average of 0.25 ± 0.25 mg/kg) in soil, which was lower than that content in China (0.29 mg/kg). The Se content of wheat grain was 0.001–1.50 mg/kg (average of 0.11 ± 0.19 mg/kg). The distribution trend of the Se content in wheat grains was different from that of the total soil Se, but it was consistent with the distribution of soil bioavailable Se content. The bioavailable Se accounted for 11.1% of the total soil Se. This could be attributed to relatively high soil Se bioavailability of the study area belonging to alkaline soil (with a pH of approximately 8). Both redundancy analysis and path analysis revealed that soil pH and organic matter were the dominant influential factors of soil Se bioavailability in Shaanxi wheat–producing area, and the soil Se bioavailability increased with these two parameters raising. On this basis, a prediction model was established to predict the Se content in wheat grain. The results show that the various agronomic measures could be used to produce Se-enriched wheat by regulating the soil pH and the organic matter content in Se biofortification practice.

Effects of selenium application on biochemical characteristics and biofortification level of kohlrabi (Brassica oleracea L. var. gongylodes) produce

Background: Biofortification of vegetables with selenium (Se) greatly depends on species tolerance to Se supply. Due to the scant information regarding kohlrabi Se biofortification, the aim of the present work was the evaluation of foliar sodium selenate application on yield and biochemical characteristics of three kohlrabi cultivars. Material and methods: A two years field experiment was conducted in Moscow region (Russia) on 3 kohlrabi cultivars using foliar biofortification with Na2Se04 solutions (50, 75 and 100 mg/L) and subsequent biochemical analysis of roots, stems and leaves. Results: Out of the three concentrations tested (50, 75 and 100 mg/L) plus an untreated control, the Se 75 dose demonstrated the strongest growth stimulation effect resulting in the increase of stem weight (by 1.35-1.61 times), yield (1.37-1.66 times), monosaccharide (1.59-2.24 times), ascorbic acid (1.54-2.01 times) and total phenolic levels (by 1.23-1.37 times), compared to the untreated control. The biofortification values varied from 69.4 (White Vienna 1390) to 59.9 (Dobrynya F1 hybrid) and 43.6 (Sonata F1 hybrid) under the Se dose of 100 mg/L. The maximum Se content in kohlrabi stems reached 4.40 mg/kg d.w. for Sonata F1, 3.53 mg/kg d.w. for Dobrynya F1 hybrids and 5.20 mg/kg d.w. for cultivar White Vienna 1390. Significant correlations were revealed between Se and total phenolics (0.720; p < 0.002), ascorbic acid (0.842; p < 0.001), monosaccharides (0.898; p < 0.001) and total sugar (0.764; p < 0.001). No significant changes in nitrate levels and dry matter content were recorded as the result of Se supply. Conclusion: The outcomes of the present research demonstrated the high benefits of Se application in improving kohlrabi yield and nutritional quality.

Selenium enriched Hypsizygus marmoreus, a potential food supplement with improved Se bioavailability

Selenium is an essential element for mammals and Se-methylselenocysteine was considered as most beneficial Se forms for humans. To better understand Se biofortification in mushrooms and find biosynthetic Se-methylselenocysteine resource, we evaluated the effects of selenate, selenite, and selenium nanoparticles on the growth and development of Hypsizygus marmoreus, and analyzed their uptake and biotransformation in this edible mushroom. Our results showed the fruiting bodies yield was not affected by these inorganic Se forms at 0.5–40.0 μg g−1, and Se in caps was higher than that in stipes. The mycelia growth was more sensitive to selenite than selenate and SeNPs. The absorbed inorganic Se forms were converted to selenomethionine (9.0%–54.8%) and selenocystine (26.3%–79.2%) in mycelia, and to selenomethionine (51.8%–76.3%), Se-methylselenocysteine (18.8%–39.4%), and selenocystine (2.2%–3.1%) in fruiting body. The health beneficial Se-methylselenocysteine accounted for 18.8%, 39.4%, and 22.5% of the total Se content in fruiting bodies supplied by selenate, selenite, and SeNPs, respectively. The results, for the first time, revealed that SeNPs was converted to organic forms of Se in mushroom and the H. marmoreus will be a good resource for Se-methylselenocysteine biosynthesis. Altogether, the findings indicate that Se-enriched H. marmoreus is a novel Se food-based source for human beings.

Quantification and Tissue Localization of Selenium in Rice (Oryza sativa L., Poaceae) Grains: A Perspective of Agronomic Biofortification.

In worldwide production, rice is the second-most-grown crop. It is considered a staple food for many populations and, if naturally enriched in Se, has a huge potential to reduce nutrient deficiencies in foodstuff for human consumption. This study aimed to develop an agronomic itinerary for Se biofortification of Oryza sativa L. (Poaceae) and assess potential physicochemical deviations. Trials were implemented in rice paddy field with known soil and water characteristics and two genotypes resulting from genetic breeding (OP1505 and OP1509) were selected for evaluation. Plants were sprayed at booting, anthesis and milky grain phases with two different foliar fertilizers (sodium selenate and sodium selenite) at different concentrations (25, 50, 75 and 100 g Se·ha−1). After grain harvesting, the application of selenate showed 4.9–7.1 fold increases, whereas selenite increased 5.9–8.4-fold in OP1509 and OP1505, respectively. In brown grain, it was found that in the highest treatment selenate or selenite triggered much higher Se accumulation in OP1505 relatively to OP1509, and that no relevant variation was found with selenate or selenite spraying in each genotype. Total protein increased exponentially in OP1505 genotype when selenite was applied, and higher dosage of Se also increased grain weight and total protein content. It was concluded that, through agronomic biofortification, rice grain can be enriched with Se without impairing its quality, thus highlighting its value in general for the industry and consumers with special needs.

Exploring the new dimensions of selenium research to understand the underlying mechanism of its uptake, translocation, and accumulation.

Selenium (Se) is a vital mineral for both plants and animals. It is widely distributed on the earth's crust and is taken up by the plants as selenite or selenate. Plants substantially vary in their physiological response to Se. The amount of Se in edible plants is genetically controlled. Its availability can be determined by measuring its phytoavailability in soil. The low concentration of Se in plants can help them in combating stress, whereas higher concentrations can be detrimental to plant health and in most cases it is toxic. Thus, solving the double-edged sword problem of nutritional Se deficiency and its elevated concentrations in environment requires a better understanding of Se uptake and metabolism in plants. The studies on Se uptake and metabolism can help in genetic biofortification of Se in plants and also assist in phytoremediation. Moreover, Se uptake and transport, especially biochemical pathways of assimilation and incorporation into proteins, offers striking mechanisms of toxicity and tolerance. These developments have led to a revival of Se research in higher plants with significant break throughs being made in the previous years. This review explores the new dimensions of Se research with major emphasis on key research events related to Se undertaken in last few years. Further, we also discussed future possibilities in Se research for crop improvement.

Soil-applied selenite increases selenium and reduces cadmium in roots of Moringa oleifera

Deficiency of selenium (Se) will lead to malnutrition and decreased immune function of the body. There is a common phenomenon of Se deficiency in foods. In this study, different concentrations of sodium selenite (Na2SeO3) were applied to Moringa oleifera grownin soil. The purpose was to explore the feasibility of Se biofortification of M. oleifera root. The effect of exogenous Se on the accumulation of Se and cadmium (Cd) in the roots of M. oleifera was studied by inductively coupled plasma mass spectrometry, and the mechanism of exogenous Se on the accumulation of Se and Cd in the roots was studied by Fourier transform infrared spectroscopy (FTIR) combined with principal component analysis and partial least squares regression analysis. The results showed that Na2SeO3 significantly affected the accumulation of Se and Cd in the roots (p < 0.05). The increase in Se was highest when Na2SeO3 was around 4.0 mg/kg, which increased by 315% compared with the control. The decrease in Cd was the lowest when Na2SeO3 was around 2.0 mg/kg, which decreased by 80% compared with the control. The results of FTIR analysis showed that Na2SeO3 treatment changed the carboxylate, phosphate radical, hemicellulose and protein in roots of M. oleifera, while the increase of Se was related to hemicellulose, protein, polysaccharide and lignin, and the decrease of Cd was related to hemicellulose and protein. The results showed that exogenous Se increased the accumulation of Se and inhibited the absorption of Cd. Therefore, the roots of M. oleifera can be used in Se biofortified products.

Selenium Biofortification and Interaction With Other Elements in Plants: A Review.

Selenium (Se) is an essential element for humans and animals and its deficiency in the diet is a global problem. Crop plants are the main source of Se for consumers. Therefore, there is much interest in understanding the factors that govern the accumulation and distribution of Se in the tissues of crop plants and the mechanisms of interaction of Se absorption and accumulation with other elements, especially with a view toward optimizing Se biofortification. An ideal crop for human consumption is rich in essential nutrient elements such as Se, while showing reduced accumulation of toxic elements in its edible parts. This review focuses on (a) summarizing the nutritional functions of Se and the current understanding of Se uptake by plant roots, translocation of Se from roots to shoots, and accumulation of Se in grains; and (b) discussing the influence of nitrogen (N), phosphorus (P), and sulfur (S) on the biofortification of Se. In addition, we discuss interactions of Se with major toxicant metals (Hg, As, and Cd) frequently present in soil. We highlight key challenges in the quest to improve Se biofortification, with a focus on both agronomic practice and human health.

Biofortification and bioavailability of Zn, Fe and Se in wheat: present status and future prospects.

Knowledge of genetic variation, genetics, physiology/molecular basis and breeding (including biotechnological approaches) for biofortification and bioavailability for Zn, Fe and Se will help in developing nutritionally improved wheat. Biofortification of wheat cultivars for micronutrients is a priority research area for wheat geneticists and breeders. It is known that during breeding of wheat cultivars for productivity and quality, a loss of grain micronutrient contents occurred, leading to decline in nutritional quality of wheat grain. Keeping this in view, major efforts have been made during the last two decades for achieving biofortification and bioavailability of wheat grain for micronutrients including Zn, Fe and Se. The studies conducted so far included evaluation of gene pools for contents of not only grain micronutrients as above, but also for phytic acid (PA) or phytate and phytase, so that, while breeding for the micronutrients, bioavailability is also improved. For this purpose, QTL interval mapping and GWAS were carried out to identify QTLs/genes and associated markers that were subsequently used for marker-assisted selection (MAS) during breeding for biofortification. Studies have also been conducted to understand the physiology and molecular basis of biofortification, which also allowed identification of genes for uptake, transport and storage of micronutrients. Transgenics using transgenes have also been produced. The breeding efforts led to the development of at least a dozen cultivars with improved contents of grain micronutrients, although land area occupied by these biofortified cultivars is still marginal. In this review, the available information on different aspects of biofortification and bioavailability of micronutrients including Zn, Fe and Se in wheat has been reviewed for the benefit of those, who plan to start work or already conducting research in this area.

Two new selenite reducing bacterial isolates from paddy soil and the potential Se biofortification of paddy rice.

Selenium (Se) is an essential element for human health. Se-enriched agricultural products can promote people's intake of Se. Microorganisms play an important role in Se cycling. In this study, two new bacterial strains were isolated from paddy soil and were identified as Chitinophaga sp. and Comamonas testosteroni, respectively. More than 44% and 39% of 1.0 mM selenite were reduced in 84 h by them using yeast extract as carbon source, respectively. Scanning electron microscope (SEM) and Energy dispersive X-ray spectrometry (EDS) results indicated that the reduction product of selenite was nanometer Se. These strains could promote the available Se in soil and the content of Se in rice plants in pot experiments. Organic combined Se in soils was increased up to 35%, accompanied by the 92% and 130% increase of Se in rice plants. To our best knowledge, this is the first report of Se reduction by Chitinophaga. This work might provide a prospective strategy for microbial fortification of Se in corps.

Combined use of arbuscular mycorrhizal fungus and selenium fertilizer shapes microbial community structure and enhances organic selenium accumulation in rice grain

Selenium (Se) deficiency is a public health concern that is mainly caused by inadequate intake of Se from staple crops. The purpose of this study is to investigate the effects of inoculation with different arbuscular mycorrhizal fungus (AMF) strains, including Funneliformis mosseae (Fm) and Glomus versiforme (Gv), and fertilization with selenite or selenate on the accumulation and speciation of Se in rice. The results showed that using both AMF inoculation and Se fertilization could promote organic Se accumulation in rice grain than using only Se fertilization. Moreover, grain of rice inoculated with Fm and grown in soil fertilized with selenate had the highest accumulation of Se, of which selenomethionine was the dominant Se species. The AMF inoculation also led to high content of available Se and high relative abundance of Firmicutes in soil. The high concentration of available Se in soil suggests that the AMF inoculation may modify the microbial community, which then causes the Se uptake of rice to increase, in turn causing the amount of organic Se accumulated in rice to increase. Based on these results, using AMF inoculation combined with Se fertilization can be a promising strategy for Se biofortification in rice.

Using gypsum and selenium foliar application for mineral biofortification and improving the bioactive compounds of garlic ecotypes

Garlic is known for its capacity to accumulate sulfur (S) and selenium (Se) in its bulbs. Therefore, it is a brilliant plant crop for S and Se biofortification and enrichment of consumers' diet with these elements. However, environmental and consumer concerns may limit mineral biofortification of plant crops by chemical fertilizers. This study investigated the effects of using a natural source of S, gypsum (0, 20, and 40 ppm S in the soil) and foliar application of Se (0, 15, and 30 ppm Se) on mineral biofortification of two of Iranian garlic ecotypes (Gorgan and Ramhormoz). After 40 days, the plants were harvested and their mineral composition and bioactive compounds were evaluated. In both ecotypes, the use of S with low Se concentration increased antioxidative capacity of the bulbs. Simultaneous application of S and Se resulted in the highest concentration of total phenolics in both ecotypes. Effect of application of selenium and sulfur on flavonoids' concentration in the bulbs of the ecotypes was different. Gorgan ecotype had the highest flavonoids' concentration under low sulfur concentration, while Ramhormoz ecotype obtained the highest flavonoids following application of high concentrations of S and Se. In both ecotypes, the highest content of allicin was found in high S but with low Se levels. Moreover, in parallel with increasing of S and Se levels, concentration of these elements increased in both ecotypes. The highest concentrations of selenium and sulfur in the bulbs (969.9 μg kg−1 DM and 1.97 mg g−1 DM, respectively) were observed in high S combined with high Se in Gorgan ecotype. Therefore, this study demonstrated the possibility of improving the nutritional value of garlic by simultaneous application of gypsum and Se foliar spray.

Selenite Uptake and Transformation in Rice Seedlings (Oryza sativa L.): Response to Phosphorus Nutrient Status.

Selenite and phosphate share similar uptake mechanisms, as a phosphate transporter is involved in the selenite uptake process. However, the mechanism by which selenium (Se) transformation in plants is mediated by phosphorus (P) remains unclear. In this hydroponic study, the absorption, translocation, and biotransformation of Se in selenite-treated rice (Oryza sativa L.) seedlings were investigated under varying P nutrient status. The results showed that P-deficient cultivation increased the Se concentration in roots with Se-only treatment by 2.1 times relative to that of the P-normal condition. However, co-treating roots with additional P caused the Se concentration to decline by 20 and 73% compared to Se treatment alone under P-normal and P-deficient cultivation, respectively. A similar pattern was also observed in Se uptake by rice roots. With an Se-transfer factor elevated by 4.4 times, the shoot Se concentration was increased by 44% with additional P supply compared to the concentration under Se-only treatment of P deficiency; however, no significant differences were observed regarding P-normal cultivation. P deficiency increased the Se percentage by 28% within the cell wall, but reduced it by 60% in the soluble fraction of Se-only treated roots relative to that of the P-normal condition. Contrarily, compared with the Se-only treatment under P deficiency, additional P supply enhanced Se storage in the root soluble fraction by 1.3 times. The opposite tendency was observed for rice shoots. Moreover, P deficiency reduced the proportion of SeMet by 22%, but increased MeSeCys by 1.3 times in Se-only treated roots compared to those under the P-normal condition. Interestingly, MeSeCys was not detected when additional P was added to the two cultivation conditions. Unlike in the roots, only SeMet was generally detected in the rice shoots. The results demonstrate that the P nutrient status strongly affects the Se biofortification efficiency in rice seedlings by altering the Se subcellular distribution and speciation.

Selenium Uptake by Lettuce (Lactuca sativa L.) and Berseem (Trifolium alexandrinum L.) as Affected by the Application of Sodium Selenate, Soil Acidity and Organic Matter Content.

Selenium deficiency in humans and animals can be reduced through dietary supplementation. Therefore, Se biofortification strategy is important in food plants and pastures. In this study, the effects of selenium (Se) addition (4 mg Se/kg) as sodium selenate (Na2SeO4) on lettuce (Lactuca Sativa L.) and berseem cultivation (Trifolium alexandrinum L.) were investigated. The experiment was conducted under greenhouse conditions with two different soil types, an acidic (pH = 6.3) and an alkaline (pH = 8.0) soil with different organic matter content, in a completely randomized design. The results indicated higher Se content in berseem cultivated on acidic soil. It was also observed a significant reduction (~ 45%) in plant biomass of lettuce in the acidic soil combined with Se application. The results showed that leaf Se content was negatively correlated with soil organic matter. The decreased Se content in plants cultivated on the alkaline soil with high organic matter content support that the effect of pH on Se uptake decreased as the soil organic matter content increased.

Selenium Biofortification of Crop Food by Beneficial Microorganisms.

Selenium (Se) is essential for human health, however, Se is deficient in soil in many places all around the world, resulting in human diseases, such as notorious Keshan disease and Keshin–Beck disease. Therefore, Se biofortification is a popular approach to improve Se uptake and maintain human health. Beneficial microorganisms, including mycorrhizal and root endophytic fungi, dark septate fungi, and plant growth-promoting rhizobacteria (PGPRs), show multiple functions, especially increased plant nutrition uptake, growth and yield, and resistance to abiotic stresses. Such functions can be used for Se biofortification and increased growth and yield under drought and salt stress. The present review summarizes the use of mycorrhizal fungi and PGPRs in Se biofortification, aiming to improving their practical use.

Arbuscular mycorrhizal fungi increase the bioavailability and wheat (Triticum aestivum L.) uptake of selenium in soil

The interaction between arbuscular mycorrhizal (AM) fungi and selenium (Se) bioavailability in rhizosphere soils of host plants is still unclear. Pot trials were conducted to investigate the effects of inoculation of AM fungi on Se uptake in winter wheat growing on selenite (Se (IV)) or selenate (Se (VI)) spiked soils (2.5 mg kg−1) and on Se bioavailability in the rhizosphere soils. Inoculation of Funneliformis mosseae (F.m) and Glomus versiforme (G.v) significantly (P < 0.05) increased concentration of available Se (SOL–Se or EXC–Se) in the rhizosphere soils by 30.21 %–189.19 % and 12.03 %–76.35 % in Se (IV)- or Se (VI)- spiked soils, and the effect of inoculatingF.m was better than G.v. Se content in winter wheat was significantly (P < 0.05) enhanced by 24.11–56.06 % and 20.27-56.49 % in Se (IV)- or Se (VI)- spiked soils inoculated with F.m and G.v. The present results also showed that Se availability in rhizosphere soils of wheat was apparently influenced by speciation of exogenous Se. In addition, correlation analysis showed that soil organic matter (SOM), dissolved organic carbon (DOC), easily extractable glomalin-related soil protein (EE-GRSP), fungi and actinomyces abundance were significantly positively correlated with available Se in the rhizosphere soils, while were negatively correlated with pH. The present study indicated that inoculation of AM fungi could increase Se bioavailability in the rhizosphere soils via influencing partial soil chemical properties including pH, SOM, DOC, EE-GRSP and microbial quantities, consequently enhancing Se uptake in winter wheat. This study can provide a theoretical basis for the study of AM fungi on Se biofortification of winter wheat.

Selenium Biofortification Impacts the Nutritive Value, Polyphenolic Content, and Bioactive Constitution of Variable Microgreens Genotypes.

Selenium (Se) is considered essential for human nutrition as it is involved in the metabolic pathway of selenoproteins and relevant biological functions. Microgreens, defined as tender immature greens, constitute an emerging functional food characterized by overall higher levels of phytonutrients than their mature counterparts. The nutraceutical value of microgreens can be further improved through Se biofortification, delivering Se-enriched foods and potentially an enhanced content of bioactive compounds. The current study defined the effect of sodium selenate applications at three concentrations (0, 8, and 16 μM Se) on the bioactive compounds and mineral content of coriander, green basil, purple basil, and tatsoi microgreens grown in soilless cultivation. Analytical emphasis was dedicated to the identification and quantification of polyphenols by UHPLC-Q-Orbitrap-HRMS, major carotenoids by HPLC-DAD, and macro micro-minerals by ICP-OES. Twenty-seven phenolic compounds were quantified, of which the most abundant were: Chlorogenic acid and rutin in coriander, caffeic acid hexoside and kaempferol-3-O(caffeoyl) sophoroside-7-O-glucoside in tatsoi, and cichoric acid and rosmarinic acid in both green and purple basil. In coriander and tatsoi microgreens, the application of 16 μM Se increased the total phenols content by 21% and 95%, respectively; moreover, it improved the yield by 44% and 18%, respectively. At the same Se dose, the bioactive value of coriander and tatsoi was enhanced by a significant increase in rutin (33%) and kaempferol-3-O(feruloyl)sophoroside-7-O-glucoside (157%), respectively, compared to the control. In green and purple basil microgreens, the 8 μM Se application enhanced the lutein concentration by 7% and 19%, respectively. The same application rate also increased the overall macroelements content by 35% and total polyphenols concentration by 32% but only in the green cultivar. The latter actually had a tripled chicoric acid content compared to the untreated control. All microgreen genotypes exhibited an increase in the Se content in response to the biofortification treatments, thereby satisfying the recommended daily allowance for Se (RDA-Se) from 20% to 133%. The optimal Se dose that guarantees the effectiveness of Se biofortification and improves the content of bioactive compounds was 16 μM in coriander and tatsoi, and 8 μM in green and purple basil.

Selenium Metabolism in Hemp (Cannabis sativa L.)-Potential for Phytoremediation and Biofortification.

Selenium (Se) deficiency and toxicity affect over a billion people worldwide. Plants can mitigate both problems, via Se biofortification and phytoremediation. Here we explore the potential of hemp (Cannabis sativa L.) for these phytotechnologies. Field surveys in naturally seleniferous agricultural areas in Colorado, United States, found 15-25 μg of Se/g in seed and 5-10 μg of Se/g dry weight (DW) in flowers and leaves. Thus, 4 g of this hemp seed provides the U.S. recommended daily allowance of 55-75 μg of Se. In controlled greenhouse experiments, hemp seedlings grown in Turface supplied with 40-320 μM selenate showed complete tolerance up to 160 μM and accumulated up to 1300 mg of Se/kg shoot dry weight. Mature hemp grown in Turface supplied with 5-80 μM selenate was completely tolerant up to 40 μM selenate and accumulated up to 200 mg of Se/kg DW in leaves, flowers, and seeds. Synchrotron X-ray fluorescence and X-ray absorption spectroscopies of selenate-supplied hemp showed Se to accumulate mainly in the leaf vasculature and in the seed embryos, with predominant Se speciation in C-Se-C forms (57-75% in leaf and more than 86% in seeds). Aqueous seed extracts were found by liquid chromatography mass spectrometry to contain selenomethionine and methyl-selenocysteine (1:1-3 ratio), both excellent dietary Se sources. Floral concentrations of medicinal cannabidiol (CBD) and terpenoids were not affected by Se. We conclude that hemp has good potential for Se phytoremediation while producing Se-biofortified dietary products.

Current Knowledge on Selenium Biofortification to Improve the Nutraceutical Profile of Food: A Comprehensive Review.

Selenium (Se) is an important micronutrient for living organisms, since it is involved in several physiological and metabolic processes. Se intake in humans is often low and very seldom excessive, and its bioavailability depends also on its chemical form, with organic Se as the most available after ingestion. The main dietary source of Se for humans is represented by plants, since many species are able to metabolize and accumulate organic Se in edible parts to be consumed directly (leaves, flowers, fruits, seeds, and sprouts) or after processing (oil, wine, etc.). Countless studies have recently investigated the Se biofortification of plants to produce Se-enriched foods and elicit the production of secondary metabolites, which may benefit human health when incorporated into the diet. Moreover, feeding animals Se-rich diets may provide Se-enriched meat. This work reviews the most recent literature on the nutraceutical profile of Se-enriched foods from plant and animal sources.

Productive traits, selenium status and blood metabolic status in fattening lambs affected by selenium biofortified corn

The widespread selenium (Se) deficiency in soil and in feedstuffs from such soil, needs to be prevented by various methods. Recently, biofortification of Se has been carried out by soil fertilization and foliar application of crops. The aim of this study was evaluate the productive traits, Se status and blood metabolic profile in fattening lambs affected by Se biofortified corn. The research was conducted with 20 Merinolandschaf lambs of the average age of 70 days, during 30 days of fattening. The feed mixture of the control group contained corn (0.014 mg Se/kg dry matter, DM); in the experimental group (Se-BC), corn was biofortified (0.278 mg Se/kg DM). The feed mixture, hay and water were offered to lambs ad libitum. Blood was collected from the jugular vein on days 0 and 30 of experiment. Haematological indices were determined in whole blood, whereas concentrations of biochemical indices, enzyme activities, and concentrations of metabolic hormones were determined in serum. After the slaughter, samples of musculus semimembranosus, liver, kidney, lungs, spleen, peritoneum and heart tissues were taken. No significant differences were obtained in productive traits when feeding lambs with Se-BC. Higher concentrations of Se in lungs and liver (control: 0.26 and 0.75 mg/kg, respectively; Se-BC: 0.33 and 0.92 mg/kg, respectively) was determined in Se-BC compared to control. Higher activity of glutathione peroxidase enzyme in serum, higher erythrocyte count, higher content of haemoglobin and haematocrit in whole blood of Se-BC lambs were determined. The results of the study indicate the posibility of using Se-BC in lambs’ diets.