Different Concentrations Of Selenium Research Articles

Selenium treatment enhances the germination and growth of corn seedlings

Early seedling development and germination are vital phases in the life cycle of plants, as optimal germination contributes significantly to crop yields. Selenium (Se), an essential micronutrient for several organisms, including plants, plays a crucial role in improving germination and early seedling growth. Seed priming treatment is presented as a promising alternative to improve these aspects. This study aimed to evaluate the impact of priming treatment with different concentrations of selenium on germination and seedling development of Criollo maize. Two maize varieties were used and five selenium concentrations (0, 25, 50, 75 and 100 µM L-1) were tested. The results indicated that concentrations of 50 and 75 µM L-1 selenium had a noticeable positive effect on variables such as germination percentage, germination rate, germination potential and germination speed index. However, higher concentrations (100 µM L-1) showed consistently lower results, suggesting a negative impact on the germination process and initial seedling development.

Optimization of Se- and Zn-Enriched Mycelium of Lentinula edodes (Berk.) Pegler as a Dietary Supplement with Immunostimulatory Activity.

Mycelial cultures of Lentinula edodes, an edible and medicinal mushroom, have been used in our previous research to obtain selenium-containing immunomodulatory preparations. Our current attempts to obtain a new preparation containing both selenium and zinc, two micronutrients necessary for the functioning of the immune system, extended our interest in the simultaneous accumulation of these elements by mycelia growing in media enriched with selenite and zinc(II) ions. Subsequently, we have studied the effects of new L. edodes mycelium water extracts with different concentrations of selenium and zinc on the activation of T cell fraction in human peripheral blood mononuclear cells (PBMCs). Flow cytometry analysis was used to measure the expression of activation markers on human CD4+ and CD8+ T cells stimulated by anti-CD3 and anti-CD3/CD28 antibodies (Abs). It was demonstrated that statistically significant changes were observed for PD-1 and CD25 antigens on CD8+ T cells. The selenium and zinc content in the examined preparations modified the immunomodulatory activity of mycelial polysaccharides; however, the mechanisms of action of various active ingredients in the mycelial extracts seem to be different.

Influence of a selenium-containing stimulant on the growth, development and yield potential of potato plants (solanum tuberosum)

Potato (Solanum tuberosum) is one of the most consumed crops in Kazakhstan. The basis for modern potato cultivation technology is the use of healthy and virus-free material. One of these methods is micropropagation of potato plants in vitro on a nutrient medium. The addition of stimulants to the nutrient medium allows for rapid and healthy plant growth. One of the effective growth stimulants is the selenium-containing drug DAFS 25. It is well known that selenium has a beneficial effect on plant growth, flowering, adaptation to changing environmental conditions and plant resistance to certain diseases. The potato variety Sante (Dutch selection) was chosen for research. This variety is characterized as medium-early, for table use, the taste is good, it has a dense peel. There is a high keeping quality during storage. The article presents the results of the influence of selenium on potato plants in vitro on such biometric indicators as the number of leaves, stem length and root length. Plants grown on a nutrient medium with different concentrations of selenium were planted in the open ground of a closed area. At the end of the growing season, the yield of each plant under study was estimated according to the following indicators: the number of tubers per plant and the mass of tubers. It has been established that selenium favorably affects the development of tubers, adaptation and survival during transplantation, as well as productivity. To exclude the negative effect of viruses on experimental plants, enzyme immunoassay was carried out twice at the beginning and at the end of the growing season. The most effective concentration of selenium on the growth and development of potato plants in vitro was revealed.

Alleviating the adverse effects of salinity and alkalinity stresses on some physiological traits by selenium and silicon foliar applications on cucumber (Cucumis sativus L.) plants

Cucumber is one of the most important vegetables around the world which plays an important role in human nutrition. Salinity and alkalinity are two common abiotic stresses in arid and semi-arid agricultural regions that limit agricultural crop production. In order to investigate the effects of beneficial elements of selenium and silicon on physiological characteristics of cucumber under salinity and alkalinity stress conditions, a factorial experiment with a completely randomized basic design and four replications was carried out in greenhouse of Zarghan city, Shiraz. The treatments consisted of three levels of stress (non-stress, salinity stress of 75 mM sodium chloride (NaCl), alkalinity stress of 75 mM sodium bicarbonate (NaHCO3) and beneficial elements in five levels (0, 4 and 6 mg/l of sodium selenite and 75 and 100 mg/l of sodium silicate). In alkalinity-stress conditions, different concentrations of selenium and silicon caused a significant increase in leaf relative water content and total chlorophyll concentration compared with control treatment. In salinity stress condition, leaf relative water content and total chlorophyll decreased, significantly. In both stress conditions, selenium and silicon increased the carotenoids, proline, total soluble sugars, malondialdehyde and protein concentrations, and superoxide dismutase, peroxidase and catalase enzyme activities. Based on the results, selenium and silicon foliar applications led to alleviation adverse effects of salinity and alkalinity stresses on physiological traits and reducing the adverse effects of these stresses on cucumber growth.

Transcriptome analysis provides new insight into the distribution and transport of selenium and its associated metals in selenium-rich rice

Selenium is an essential trace element for humans and obtained from diary diets. The consumption of selenium-rich agricultural food is an efficient way to obtain selenium, but the quality and safety of selenium-rich agro-food are always affected by their associated heavy metals, even poses a potential threaten to human health. In this research, a sampling survey of heavy metals contents in selenium-rich rice was conducted, 182 sets of selenium-rich rice samples were collected from five selenium-rich rice-producing areas of China, and the accumulation of selenium and cadmium were found to be associated in rice and soil. Subsequently, a pot experiment was performed in the greenhouse via treating the soil samples with 12 different concentrations of selenium and heavy metals, and the contents of selenium and cadmium in rice grain were confirmed to be significantly associated. Moreover, transcriptome analysis revealed that the up-regulation of transporter-coding may promote the absorption of selenium and cadmium. The expression of antioxidant-coding genes and cadmium chelator transporter coding-genes was up-regulated to reduce the toxicity of cadmium. Meanwhile, the up-regulation of key genes of the ascorbic acid-glutathione metabolic pathway were responsible for the association between selenium and cadmium in Se-rich rice. Our work suggested the correlation between selenium and cadmium accumulation in selenium-rich rice, clarified their accumulation mechanism, provides a direction for the scientific production of selenium-rich agro-foods.

Effects of Selenium on the Chlorophylls, Gas Exchange, Antioxidant Activity and Amino Acid Composition of Lettuce Grown under an Aquaponics System

Aquaponics is a sustainable technique that is respectful to the environment, as it reuses products and minimizes the consumption of new materials. The combination of this technique with the foliar application of selenium (as Na2SeO4) could lead to healthier and more sustainable products, which are increasingly requested by consumers. Lettuce (Lactuca sativa L.) plants were grown in an aquaponics system (fish water) as compared with a control (conventional soilless fertigation), and sprayed with different concentrations of selenium (0, 4, 8, and 16 µmol L−1). The results showed a reduction in the dry weight and N content of lettuce plants irrigated with the fish water mixture treatment. However, the application of Se relieved this stress, increasing the photosynthetic rate and ABTS, and reducing the content of chlorophylls, β-carotene, and several of the measured amino acids. The best results were observed with the highest concentration of Se (16 µmol L−1), as an increase in nitrogen content was observed, as shown by a greater weight of the plant. Furthermore, this treatment produced the greatest increase in ABTS and the least reduction in amino acid content. This novel study highlights the possibility of improving the efficiency of N utilization in lettuce by applying foliar selenium in combination with an aquaponics system.

Increased selenium concentration in the synthesis of CdSe magic-sized quantum dots affects how the brain responds to oxidative stress.

CdSe magic-sized quantum dots (MSQDs) have been widely used as fluorescent probes in biological systems due to their excellent optical properties with a broader fluorescence spectrum and stable luminescence in biological media. However, they can be cytotoxic and alter the redox balance depending on the amounts of Cd2+ adsorbed on their surface. Thus, the present study aimed to evaluate whether increases in selenium concentration in the synthesis of CdSe-MSQDs decrease the oxidative stress caused by Cd2+ -based quantum dots. CdSe-MSQDs synthesized with different concentrations of selenium were investigated against oxidative stress in the brain of chicken embryos by examining total antioxidant capacity, lipid peroxidation, thiol, and glutathione contents, as well as the activities of glutathione peroxidase, superoxide dismutase (SOD), catalase (CAT), and glutathione reductase. In addition, the vascularization of the chorioallantoic membrane (CAM) analysis was performed. Higher selenium concentrations alter the surface defect levels (decrease free Cd2+ ) and controlled the oxidative effects of CdSe-MSQDs by reducing the lipid peroxidation, restoring the glutathione defense system and the antioxidant enzymes SOD and CAT, and maintaining the vascular density of the CAM. The current findings reinforce the study of the effects of the presence of Cd2+ ions on the surface of quantum dots, changing toxicity, and aiming interesting strategies of nanomaterials in biological systems.

Survival of Embryos and Fry of Sea Trout (Salmo trutta m. trutta) Growing from Eggs Exposed to Different Concentrations of Selenium during Egg Swelling.

Simple SummarySelenium-poor areas are defined in the Earth. Adequate selenium (Se) consumption enhances the health and growth of organisms, but overdose of it can be harmful and pathogenic. The objective of the study was to investigate Se supplementation effects in the non-feeding stages of fish. Fertilised eggs of sea trout were immersed in water enriched with Se during the egg-swelling period. Se at a concentration from 0.5 to 8 mg Se L−1 slightly impacted the hatching rate. A higher concentration of Se resulted in declined survival of embryos. Accumulation of Se in the body of hatch increased with the increase of element concentration in the aqueous environment during egg swelling. The survival of fry was similar in all groups, while the fry length and weight correlated positively with Se concentration in its body. In Se-poor areas, immersion of fertilised eggs in water enriched with Se during egg swelling can be used to supplement the deficient element to fish in order to improve breeding outcomes in aquaculture.Adequate selenium (Se) availability enhances the health and growth of organisms, but overdose of it can be harmful and pathogenic. The study’s objective was to analyse the impact of short-term exposure of sea trout fertilised eggs to inorganic selenium (SeO2) at concentrations from 0 to 32 mg Se L−1 to find the optimal and toxic dose of Se on early fish development. Se accumulated in the body, embryos’ survival rate, and growth in the first four months of life was examined. Swelling of fertilised eggs in water supplemented with Se at a concentration from 0.5 to 8 mg Se L−1 was associated with a slightly positive impact on the hatching rate. At higher Se concentration, a harmful effect on the survival of the embryo was observed. The survival of fry was similar in all groups, while the fry length and weight correlated positively with Se concentration in its body. Immersion of fertilised eggs in water enriched with Se during egg swelling can constitute a method to supplement the element to non-feeding stages of fish. In selenium-poor areas, this innovative method can be implemented in aquaculture to improve breeding outcomes. Se concentration should be adjusted to the chemical compound, fish species, and Se’s content in the yolk.

The First Evidence of the Beneficial Effects of Se-Supplementation on In Vitro Cultivated Olive Tree Explants.

Selenium is an essential micronutrient that provides important benefits to plants and humans. At proper concentrations, selenium increases plant growth, pollen vitality, the shelf life of fresh products, and seems to improve stress resistance; these effects can certainly be attributed to its direct and indirect antioxidant capacity. For these reasons, in the present work, the effects of selenium at different dosages on in vitro cultivated olive explants were investigated to observe possible positive effects (in terms of growth and vigor) on the proliferation phase. The work was carried out on four different olive cultivars: “San Felice”, “Canino”, “Frantoio”, and “Moraiolo”. The explants were cultured in aseptic conditions on olive medium (OM), with the addition of 4 mg·L−1 of zeatin, 30 g·L−1 of sucrose, and 7 g·L−1 of agar. The experimental scheme included a comparison between explants grown with five different concentrations of Na2SeO4 (0, 10, 20, 40, and 80 mg L−1) added to the medium during three successive subcultures. Interesting information has emerged from the results and all varieties responded to different concentrations of Selenium. The optimal Se dosages varied for each cultivar, but in general, Se concentration between 10 and 40 mg L−1 increased fresh and dry weight of the explants and shoot lengths. Se treatment induced in all cultivars and for all dosages used an increase in total Se content in proliferated explants. Furthermore, as the subcultures proceeded, the ability of the explants to absorb Se did not diminish. The Se content ranged from 8.55 to 114.21 µg kg−1 plant DW in ‘Frantoio’, from 9.83 to 94.85 µg kg−1 plant DW in ‘Moraiolo’, from 19.84 to 114.21 µg kg−1 plant DW in ‘Canino’, and from 20.97 to 95.54 µg kg−1 plant DW in ‘San Felice’. In general, the effect of selenium tends to decrease with the progress of subcultures and this suggests a sort of “adaptation” effect of the explants to its presence. The present study highlights for the first time the possibility of using in vitro cultures as biotechnological support to study supplementation with selenium and its effects on in vitro olive plant growth.

Genome-wide identification of SULTR genes in tea plant and analysis of their expression in response to sulfur and selenium.

Sulfur (S) is an essential macronutrient required by plants. Plants absorb and transport S through sulfate transporters (SULTRs). In this study, we cloned 8 SULTR genes (CsSULTR1;1/1;2/2;1/3;1/3;2/3;3/3;5/4;1) from tea plant (Camellia sinensis), all of which contain a typical sulfate transporter and antisigma factor antagonist (STAS) conserved domain. Phylogenetic tree analysis further divided the CsSULTRs into four main groups. Many cis-acting elements related to hormones and environmental stresses were found within the promoter sequence of CsSULTRs. Subcellular localization results showed that CsSULTR4;1 localized in the vacuolar membrane and that other CsSULTRs localized to the cellular membrane. The tissue-specific expression of the 8 CsSULTR genes showed different expression patterns during the active growing period and dormancy period. In particular, the expression of CsSULTR1;1 was highest in the roots, but that of CsSULTR1;2 was lowest in the dormancy period. The expression of CsSULTR1;1/1;2/2;1/3;2 was stimulated under different concentrations of selenium (Se) and S; moreover, CsSULTR1;2/2;1/3;3/3;5 was upregulated in response to different valences of Se.

Effect of Selenium and Iodine on Oxidative Stress in the First Trimester Human Placenta Explants.

Imbalanced maternal micronutrient status, poor placentation, and oxidative stress are associated with greater risk of pregnancy complications, which impact mother and offspring health. As selenium, iodine, and copper are essential micronutrients with key roles in antioxidant systems, this study investigated their potential protective effects on placenta against oxidative stress. First trimester human placenta explants were treated with different concentrations of selenium (sodium selenite), iodine (potassium iodide), their combination or copper (copper (II) sulfate). The concentrations represented deficient, physiological, or super physiological levels. Oxidative stress was induced by menadione or antimycin. Placenta explants were collected, fixed, processed, and embedded for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) element imaging or immunohistochemical labelling. LA ICP-MS showed that placenta could uptake selenium and copper from the media. Sodium selenite and potassium iodide reduced DNA damage and apoptosis (p < 0.05). Following oxidative stress induction, a higher concentration of sodium selenite (1.6 µM) was needed to reduce DNA damage and apoptosis while both concentrations of potassium iodide (0.5 and 1 µM) were protective (p < 0.05). A high concentration of copper (40 µM) increased apoptosis and DNA damage but this effect was no longer significant after induction of oxidative stress. Micronutrients supplementation can increase their content within the placenta and an optimal maternal micronutrient level is essential for placenta health.

Selenium supplementation prevents DNA damage in ram spermatozoa

ABSTRACT: In the present study, we aimed to evaluate the effects of different concentrations of selenium (Se) ovine nutritional supplementation on spermatozoa DNA integrity. Thirty male ovines (age: 10 months) were used. They were fed with hay and ram food in an intensive system, which was divided into stalls (5 m long and 3 m wide) with feeding troughs, and had ad libitum access to food and water. Ovines in group 1 (G1, the negative control) received mineral salt supplementation without Se; ovines in G2 received the same mineral salt mixed with 5 mg Se (as sodium selenite)/kg mineral supplement;ovines in G3 received 10 mg Se/kg mineral supplement; ovines in G4 received 15 mg Se/kg mineral supplement; and ovines in G5 received 20 mg Se/kg mineral supplement. Ovines in all groups remained untreated for 14 days, followed by a treatment period of 56 days. Semen samples were obtained by electroejaculation. The DNA damage in semen samples was evaluated using the comet assay. The experimental design was implemented using a 5 × 5 Latin Square, i.e., five treatments and five experimental periods. The mean differences were compared using Tukey’s test at a significance level of 5%. The control group (G1) showed a high percentage of DNA damage compared to the Se-treated groups (G2-G5). Therefore, Se supplementation could decrease the basal level of DNA damage in sperm cells, suggesting that Se might exert protective effects on sperm DNA.

Protective effects of selenium on Bisphenol A-induced oxidative stress in mouse testicular mitochondria and sperm motility.

Objective:This study aimed to explore the impact of selenium (SE) on Bisphenol-A (BPA)-exposed sperm and isolated testicular mitochondria of mice.Methods:Mouse sperm and isolated mitochondria were exposed to BPA (0.8 mM) and different concentrations of SE (50, 100, and 200 µM) for four hours. The viability of sperm and isolated mitochondria as well as the mitochondrial membrane potential (MMP) were evaluated. SOD (superoxide dismutase), GSH (glutathione), MDA (malondialdehyde), and ROS (reactive oxygen species) levels in testicular mitochondria were also examined.Results:BPA concentration-dependently enhanced ROS and MDA levels in isolated mitochondria, while MMP and acclivity of GSH and SOD significantly reduced. BPA also considerably impaired spermatozoa survival and motility. SE concentration-dependently reduced mitochondrial oxidative stress, MMP, sperm survival, and total sperm motility.Conclusions:Our findings collectively suggested that SE concentration-dependently reversed BPA-caused mitochondrial toxicity and reduced sperm motility by suppressing oxidative stress.

Cul5-type Ubiquitin Ligase KLHDC1 Contributes to the Elimination of Truncated SELENOS Produced by Failed UGA/Sec Decoding.

SummaryThe UGA codon signals protein translation termination, but it can also be translated into selenocysteine (Sec, U) to produce selenocysteine-containing proteins (selenoproteins) by dedicated machinery. As Sec incorporation can fail, Sec-containing longer and Sec-lacking shorter proteins co-exist. Cul2-type ubiquitin ligases were recently shown to destabilize such truncated proteins; however, which ubiquitin ligase targets truncated proteins for degradation remained unclear. We report that the Cul5-type ubiquitin ligase KLHDC1 targets truncated SELENOS, a selenoprotein, for proteasomal degradation. SELENOS is involved in endoplasmic reticulum (ER)-associated degradation, which is linked to reactive oxygen species (ROS) production, and the knockdown of KLHDC1 in U2OS cells decreased ER stress-induced cell death. Knockdown of SELENOS increased the cell population with lower ROS levels. Our findings reveal that, in addition to Cul2-type ubiquitin ligases, KLHDC1 is involved in the elimination of truncated oxidoreductase-inactive SELENOS, which would be crucial for maintaining ROS levels and preventing cancer development.

Isolation of Indigenous Selenium Tolerant Yeast and Investigation of the Relationship Between Growth and Selenium Biotransformation.

Purpose: Organic selenium compound such as selenomethionine plays a significant function in the response to oxidative stress. Saccharomyces cerevisiae have the ability to accumulate selenium and selenium biotransformation. Selection of indigenous selenium tolerant yeast is our goals. The relationship between cell growth and selenium biotransformation was also investigated. Methods: The screening of the yeast cell was carried out at two steps in order to select yeast with high capacity for resistance and accumulation of selenium. The isolates were selected according to produced high biomass at different concentrations of selenium. Secondly, best yeast strains from previous step were grown in presence of 25 mg/L of sodium selenite and organic selenium content was measured. Results: The S17 isolate showed had maximum organic selenium accumulation (2515 ppm) and biomass production (2.73 g/L) compared to the other isolates. The biomass production and organic selenium accumulation of the S17 during 120 hours was shown a direct relationship between growth and biotransformation. Conclusion: This increase in organic selenium content was achieved with yeast screening. It is interesting to know that organic selenium has high bioavailability and low toxicity compared with inorganic selenium. Therefore, finding yeast strains which are resistant to selenium can be very helpful in cancer prevention.

Effects of different selenium concentrations on the stress resistance of grape seedlings

The effects of different concentrations of selenium (0.00, 0.05, 0.10, 0.25, 0.50, 1.00, 2.00 mg/L) on the stress resistance of grape seedlings were studied by pot experiment. The results showed that the proline content in different parts of grape seedlings showed an increasing trend with the increase of selenium concentration. The activities of SOD, POD and CAT, as well as the relative conductivity, malondialdehyde and soluble protein content of grape seedlings increased first and then decreased with the increase of exogenous selenium concentration. When the concentration of selenium was 0.50 mg/L, the antioxidant enzyme activity and the content of permeate in grape seedlings reached the maximum. In summary, low concentration of selenium can effectively improve the stress resistance of grape seedlings, but when the concentration of selenium is higher than 0.50 mg/L, it has a toxic effect on grape seedlings.

Impact of Selenium and Copper Nanoparticles on Yield, Antioxidant System, and Fruit Quality of Tomato Plants.

The effects of nanoparticles (NPs) on plants are contrasting; these depend on the model plant, the synthesis of the nanoparticles (concentration, size, shape), and the forms of application (foliar, substrate, seeds). For this reason, the objective of this study was to report the impact of different concentrations of selenium (Se) and copper (Cu) NPs on yield, antioxidant capacity, and quality of tomato fruit. The different concentrations of Se and Cu NPs were applied to the substrate every 15 days (five applications). The yield was determined until day 102 after the transplant. Non-enzymatic and enzymatic antioxidant compounds were determined in the leaves and fruits as well as the fruit quality at harvest. The results indicate that tomato yield was increased by up to 21% with 10 mg L−1 of Se NPs. In leaves, Se and Cu NPs increased the content of chlorophyll, vitamin C, glutathione, 2,2′-azino-bis(3-ethylbenzthiazolin-6-sulfonic acid (ABTS), superoxide dismutase (SOD), glutathione peroxidase (GPX) and phenylalanine ammonia liasa (PAL). In fruits, they increased vitamin C, glutathione, flavonoids, firmness, total soluble solids, and titratable acidity. The combination of Se and Cu NPs at optimal concentrations could be a good alternative to improve tomato yield and quality, but more studies are needed to elucidate their effects more clearly.

Effects of Different Selenium Concentrations on Photosynthetic Physiology of Grape Seedlings

A hydroponic experiment was conducted to study the effects of different concentrations of selenium (0.00, 0.05, 0.10, 0.25, 0.50, 1.00, 2.00 mg/L) on photosynthetic physiology of grape seedlings. The result showed that the selenium concentration of 0.05 mg/L could significantly improve the chlorophyll a, chlorophyll b, carotenoid and total chlorophyll of grape seedlings, while the chlorophyll content reduced significantly when the concentration was 1.00 mg/L and 2.00 mg/L. Besides, the net photosynthetic rate (Pn), stomatal conductance (Gs), CO2 concentration of intercellular (Ci) and transpiration rate (Tr) of grape seedlings all significantly increased at 0.05 mg/L, while the Pn, Gs, Ci and Tr of grape seedlings reduced significantly when the concentration was 1.00 mg/L and 2.00 mg/L. Therefore, the selenium concentration of 0.05 mg/L concentration was beneficial to photosynthesis.

Physicochemical Contents, Antioxidant Activities, and Acute Toxicity Assessment of Selenium-Enriched Chinese Kale (Brassica oleracea var. alboglabra L.) Seedlings

The oxidative activities of hydroponically produced Chinese kale (Brassica oleracea var. alboglabra L.) seedlings grown under different concentrations of selenium (Se) biofortification with sodium selenite (Na2SeO3) at 0, 5, 10, 15, and 30 mg·Se/L and different ages (5, 10, and 15 days after germination) were determined by the electron transfer method (DPPH and FTC). Highest antioxidant activities of Se-enriched Chinese kale seedlings (Se-KS) were found in seedlings grown on 30 mg·Se/L, 15 days after germination. The physicochemical contents (moisture, crude fibre, ash, crude protein, and carbohydrate), total Se contents, and Se bioaccessibility and antioxidant activities (after treatment with an in vitro simulated gastrointestinal digestion process) between Se-KS and a control of regular Chinese kale seedlings (R-KS) were compared. The crude protein and total Se contents of the air-dried matter in Se-KS were higher (37 ± 1% and 433 ± 22 mg·Se/kg) than those of the R-KS (33 ± 2% and 17 ± 3 mg·Se/kg). Total Se content and antioxidant activities were strongly correlated in the range from 0.93 to 0.99. Testing acute toxicity, a single dose of the Se-KS was orally administrated to rats at 1250, 2500, and 5000 mg/kg·b.w., which consisted of 0.54, 1.08, and 2.16 mg Se/kg·b.w., respectively. These results demonstrated that Se-KS did not create any toxicological signs and mortality. No abnormal pathological changes in the liver, kidney, and heart were found. The results suggested that the Se-KS could be a good source of organo Se for development as a new Se supplementary product.

Study on Selenium Accumulation Characteristics of Radish

In order to study the effects of different concentrations of selenium on the selenium accumulation characteristics of radish, we used the pot experiment to study effects of different selenium concentrations (0, 5, 10, 25, 50, 75, and 100 mg/kg) on the biomass and selenium content of radish. The results showed that selenium stress inhibited the biomass of radish and the higher the concentration of selenium and the stronger the inhibition of radish growth. In addition, the selenium content of radish increased with the increase of selenium concentration. Selenium content in radish roots, tubers and leaves were in the ranges of 21.71-346.64 mg/kg, 11.05-251.38 mg/kg, and 8.34-210.91 mg/kg respectively under the selenium stress. Compared with the selenium concentration of 0 mg/kg, all treatments significantly increased the tubers, leaves, shoots and whole plants of radish selenium accumulation. In all treatments, when the concentration of selenium was 25 mg/kg, the selenium accumulation of each part of radish reached the maximum and the selenium accumulation of radish in shoots and whole plants reached 111.96 μg/plant and 119.21 μg/plant respectively. In a word, radish has the strongest accumulation ability of selenium in soil when the concentration of selenium is 25 mg/kg, which can be considered as the best selenium concentration to increase the selenium content of radish.