Se-enriched Plants Research Articles

Study on Selenium Assimilation and Transformation in Radish Sprouts Cultivated Using Maillard Reaction Products.

The organic selenium (Se), particularly in the form of selenoamino acids, in non-edible sections or by-products of Se-enriched plants, has the potential to generate Maillard reaction products (MRPs) during thermal treatment or fermentation. To elucidate the recycling process of organic selenium in foods and improve the utilization rate of Se, the biotransformation of organic selenium was studied by the cultivation of edible radish sprouts with Se-MPRs. Maillard reactions were simulated using selenoamino acids (SeAAs; selenomethionine and methylselenocysteine) and reducing sugars (glucose and fructose) for preparing Se-MRPs. The structures of the possible dehydrated Se-MRPs were analyzed using a HPLC-ESI-MS/MS system based on their fragmentation patterns and Se isotopic characteristics. Se absorption by the radish sprouts cultivated using Se-MRPs was estimated by the corresponding Se in the SeAAs and the total Se contents. The capabilities of SeAA transformation and total Se assimilation by the sprouts were related to the substrate composition during the Se-Maillard reaction. A particular Se-MRP (selenomethionine + fructose) increased SeAAs transformation by 33.8% compared to selenomethionine. However, glucose and fructose seemed to inhibit the transformation of the Se-MRPs to SeAAs by 10.0 to 59.1% compared to purified Se-MRPs. These results provide key references for the efficient utilization of organic Se in the cultivation of Se-enriched sprouts.

Efficacy and selenium enrichment of Lycium barbarum in hydroponic and soil conditions in the Ararat valley

Background: It is known that 60-80% of the population affected by various diseases, such as heart attack, stroke, and oncological diseases is associated with selenium (Se) deficiency. Therefore, enriching agricultural crops with Se is considered a current issue. Objective: This study investigates Se enrichment of Lycium barbarum (Lb) and its effectiveness in hydroponic and soil conditions in the Ararat Valley. The research focuses on the impact of adding exogenous Se on plant productivity, Se accumulation, and the content of biologically active substances (BAS) in Lb berries and leaves. Methods: The experiments were conducted from 2021 to 2023 using hydroponic and soil cultivation methods with varying Se concentrations in nutrient solutions and foliar nutrition. Results: The results demonstrate that Se enrichment significantly increased Se and BAS levels in both leaves and berries of Lb, with hydroponic cultivation exhibiting higher accumulation compared to soil conditions. Foliar feeding with a 0.005% Se solution and exogenous Se addition to nutrient solutions at 1.0 mg/L resulted in notable improvements in Se content and plant productivity. Furthermore, the analyses revealed significant differences between hydroponically and soil-grown Lb, emphasizing the potential of hydroponic cultivation for producing Se-enriched plant material with enhanced BAS content. Conclusion: Hydroponic cultivation supplemented with Se and foliar nutrition is recommended for obtaining Se-rich Lb plant material, which is suitable for medicinal and functional food purposes. These findings contribute to the development of biotechnologies for Se -enriched plant production and addressing health and nutritional needs. Keywords: Goji, berries, biologically active substances, flavonoids, phenolic acids, tannins, carotenoids

Selenium-enriched plant foods: Selenium accumulation, speciation, and health functionality.

Selenium (Se) is an essential element for maintaining human health. The biological effects and toxicity of Se compounds in humans are related to their chemical forms and consumption doses. In general, organic Se species, including selenoamino acids such as selenomethionine (SeMet), selenocystine (SeCys2), and Se-methylselenocysteine (MSC), could provide greater bioactivities with less toxicity compared to those inorganics including selenite (Se IV) and selenate (Se VI). Plants are vital sources of organic Se because they can accumulate inorganic Se or metabolites and store them as organic Se forms. Therefore, Se-enriched plants could be applied as human food to reduce deficiency problems and deliver health benefits. This review describes the recent studies on the enrichment of Se-containing plants in particular Se accumulation and speciation, their functional properties related to human health, and future perspectives for developing Se-enriched foods. Generally, Se's concentration and chemical forms in plants are determined by the accumulation ability of plant species. Brassica family and cereal grains have excessive accumulation capacity and store major organic Se compounds in their cells compared to other plants. The biological properties of Se-enriched plants, including antioxidant, anti-diabetes, and anticancer activities, have significantly presented in both in vitro cell culture models and in vivo animal assays. Comparatively, fewer human clinical trials are available. Scientific investigations on the functional health properties of Se-enriched edible plants in humans are essential to achieve in-depth information supporting the value of Se-enriched food to humans.

Effect of Cardamine violifolia on Plasma Biochemical Parameters, Anti-Oxidative Capacity, Intestinal Morphology, and Meat Quality of Broilers Challenged with Lipopolysaccharide.

Simple SummarySelenium (Se) is a crucial trace nutrient for animal maintenance and growth as well as human health. Organic Se has less poisonous and better tissue retention as well as bioavailability compared to inorganic Se. Cardamine violifolia is a newly discovered Se-enriched plant rich in MeSeCys and SeCys and has a strong antioxidant capacity. This study aimed to investigate the effects of Cardamine violifolia on plasma biochemical indices, antioxidant levels, intestinal morphology, and meat quality of broilers under acute LPS-induced oxidative stress by comparing it with inorganic Se (sodium selenite). The results showed that Cardamine violifolia alleviated tissue injury, enhanced antioxidant capacity, and improved meat quality of breast and thigh muscle after LPS stress.Cardamine violifolia is a newly discovered selenium (Se)-enriched plant rich in MeSeCys and SeCys and has a strong antioxidant capacity. This study aimed to investigate the effects of Cardamine violifolia on plasma biochemical indices, antioxidant levels, intestinal morphology, and meat quality of broilers under acute LPS-induced oxidative stress by comparing it with inorganic Se (sodaium selenite). A total of 240 one-day-old Ross 308 broilers were fed a basal diet and divided into four groups: (1) SeNa-SS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.9% sterile saline, (2) SeCv-SS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia, and injected with 0.9% sterile saline, (3) SeNa-LPS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.5 mg/kg LPS, (4) SeCv-LPS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia and injected with 0.5 mg/kg LPS. The experiment lasted for 42 days. Sterile saline or LPS was injected intraperitoneally two hours before slaughter, and blood and tissue samples were collected for testing. The results showed that compared with SeNa, SeCv significantly reduced the plasma levels of aspartate aminotransferase, alanine aminotransferase, and urea nitrogen after LPS challenge (p < 0.05), and increased the plasma levels of total antioxidant capacity and glutathione peroxidase, decreased malondialdehyde content in LPS-challenged broilers (p < 0.05). In addition, compared with SeNa, SeCv supplementation increased villus height and the ratio of villus height to crypt depth of jejunum and ileum after LPS challenge (p < 0.05). Additionally, SeCv could increase the redness of breast and thigh muscle, and decrease drip loss, cooking loss, and shear force (p < 0.05). In conclusion, our results indicated that supplementing with 0.3 mg/kg Se from Cardamine violifolia alleviated tissue injury after LPS challenge, increased antioxidant capacity, and improved meat quality of breast and thigh muscle after stress.

Selenium Enriched Peanut Protein Alleviates Alcohol-Induced Liver Damage in Mice by Modulating the Composition of the Gut Microbiota

Alcohol Use Disorder (AUD) is one of leading external causes of mortality. Selenium-enriched Peanut Protein (SePP) is a type of Se compound present in Se-enriched plants. Our previous studies showed that SePP possesses potential therapeutic properties and could alleviate alcohol-induced AML-12 cytotoxicity. It spurred us to determine the underlying mechanisms and roles of SePP on gut microbiota. Here, ICR mice were fed either standard diet or ethanol (30%, v/v, 10 mL/kg bw/day) intragastric administration for 8 weeks. The intervention groups were divided into different doses of SePP groups and Se compounds groups, like Selenomethionine (SeMet) group, sodium selenite group. The composition of the gut microbiota was investigated by analyzing 16S rRNA gene sequences. Body weight, lipid metabolism markers, serum insulin and oxidative stress were assessed. Treatment with SePP at a certain dosage (25 μg/kg bw/day in Se) and SeMet reversed diversity loss and community alterations in the gut microbiota of the AUD group, as evidenced by an increased abundance of Firmicutes and decreased abundances of Bacteroidetes and Verrucomicrobia in AUD mice. SePP suppressed the relative abundance of the Rikenellaceae_RC9 gut group and increased those of Lachnospiraceae and Ruminococcaceae, which are associated with lipid metabolism and Short-Chain Fatty Acids (SCFAs) production. The study suggested that SePP has the potential to be used as a supplement for alleviating alcohol-induced liver damage.

Effects of selenium on activity of glutathione peroxidase and expression of selenium metabolism-related genes in Brassica

Inorganic selenium (Se) is absorbed and enriched by plants and converted into a stable and nutritionally important organic form, which subsequently when consumed by humans or animals results in increased Se tissue levels. Brassica is one of the most potent Se-enriched plants. The aim of this study was to compare differences in Se enrichment between two predominant Brassica plants namely Brassica rapa Linn L. and Brassica tumida Tsenet Lee L. on Se metabolic parameters. Plants exposed to soil Se levels (0, 0.5, 1, 2.5 or 5 mg/kg) were examined on the activity of glutathione peroxidase (GSH-Px), Se levels and expression of Se metabolism related genes using soil pots. Data showed that activities of GSH-Px in leaf and root of the two Brassica species were significantly increased in the presence of Se at 2.5 mg/kg. Se concentrations of leaf, stem and root in B. tumida Tsenet Lee L. and B. rapa Linn L. rose from 0.31 to 21.84-fold (leaf), 1.15 to 15.16-fold (stem) and 2.11 to 15.26-fold (root) in the presence of metal in a concentration-dependent manner. The highest expression levels of adenosine triphosphate (ATP), ATP sulfurylase (APS), selenocysteine methyltransferase (SMT), serine acetyltransferase (SAT), cysteine desulfurase (CysD) and S-adenosyl-l-Met:l-Met S-methyltransferase (MMT) in leaf of B. rapa Linn L. were found at 1 mg/kg Se. The highest expression levels of ATP, APS, SMT, SAT, CysD and MMT in leaf of B. tumida Tsenet Lee L. were observed at 2.5 mg/kg Se. The Se concentrations in leaf, stem and root of B. rapa Linn L. were higher than in B. tumida Tsenet Lee L. under the same soil Se level conditions. At the same Se level, differences in the expression of Se-related genes were observed between these two Brassica species. Our observations may be used to optimize the utilization of Brassica as a nutritional source of Se by growing this plant under certain soil conditions.

Selenium in lemon balm plants: Productivity, phytotoxicity and drought alleviation

ABSTRACTSince studies on the effects of selenium (Se) supplementation in water-stressed plants have mainly focused on cereal crops, the specific reports regarding Se-mediated adaptation to drought stress in medicinal vegetables are scant. Thus, we investigated the responses of Melissa officinalis to Se supplementation. Selenium contents were increased in leaves and grains by supplemental Se. Selenium foliar application at 1 mg l−1 could be useful to increase the vegetative and reproductive growth of Se-enriched plants under well-watered conditions but at 20 mg l−1 led to toxicity and caused damage to shoots. Drought stress significantly inhibited plant growth by chlorophyll degradation and reduced net carbon dioxide (CO2) assimilation rate. Although Se at 1 mg l−1 could increase biomass production under well-watered conditions in addition to the stimulation of antioxidant system under water stress, it could not ameliorate the negative effect of drought on productivity.

Selenium Enrichment of Horticultural Crops.

The ability of some crops to accumulate selenium (Se) is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

Selenium Biofortification and Phytoremediation Phytotechnologies: A Review.

The element selenium (Se) is both essential and toxic for most life forms, with a narrow margin between deficiency and toxicity. Phytotechnologies using plants and their associated microbes can address both of these problems. To prevent Se toxicity due to excess environmental Se, plants may be used to phytoremediate Se from soil or water. To alleviate Se deficiency in humans or livestock, crops may be biofortified with Se. These two technologies may also be combined: Se-enriched plant material from phytoremediation could be used as green fertilizer or as fortified food. Plants may also be used to "mine" Se from seleniferous soils. The efficiency of Se phytoremediation and biofortification may be further optimized. Research in the past decades has provided a wealth of knowledge regarding the mechanisms by which plants take up, metabolize, accumulate, and volatilize Se and the role plant-associated microbes play in these processes. Furthermore, ecological studies have revealed important effects of plant Se on interactions with herbivores, detrivores, pollinators, neighboring vegetation, and the plant microbiome. All this knowledge can be exploited in phytotechnology programs to optimize plant Se accumulation, transformation, volatilization, and/or tolerance via plant breeding, genetic engineering, and tailored agronomic practices.

Se-enrichment of cucumber (Cucumis sativus L.), lettuce (Lactuca sativa L.) and tomato (Solanum lycopersicum L. Karst) through fortification in pre-transplanting

We propose a new method for the fortification of crop plants with Se, based on the use of Se-enriched peat during the pre-transplanting stage. The method is as follows: (i) enrich in Se an appropriate amount of peat; (ii) sow the seeds of the selected crop species in Se-enriched peat until seedlings have the appropriate size for transplanting; (iii) transfer these Se-enriched transplants in the field. Concentrations ranging from 10 to 20mg Se per kilogram of dry peat induced a Se-enrichment in transplants without negative effects on plant growth, while higher concentrations induced a severe reduction of plant growth. Those fortified transplants showed Se concentrations from 2 to 78 times higher than those observed in the untreated control. After transplanting in the field, the edible organs of Se-enriched plants at the end of cropping cycle showed Se concentrations from 1.6 (tomato) to 8.5 (lettuce) times higher with respect to the untreated controls. The final Se concentrations in Se-enriched edible organs (on a fresh weight basis) were 29.3–48.0μgkg−1 for cucumber fruits, 22.7–53.4μgkg−1 for lettuce leaves and 15.2–19.9μgkg−1 for tomato fruits, depending on the experimental year. Plants fortified with the above technique did not show any negative effects in terms of yield level and quality with respect to controls. On the contrary, a slightly higher shelf-life (lettuce) and an increased level of vitamin A (tomato) were noted in some instances, with respect to non-enriched controls.

Biofortification and phytoremediation of selenium in China.

Selenium (Se) is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. Selenium phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed.

Seleniferous soils as a source for production of selenium-enriched foods and potential of bacteria to enhance plant selenium uptake

Selenium (Se) is an essential micronutrient for animals and humans but toxic at high levels. Soil Se concentration is highly variable. Selenium toxicity occurs in areas with seleniferous soils, while Se deficiency is prevalent in low-Se areas. Selenium-accumulating crop plants may be used to extract Se from seleniferous soils and provide dietary Se in low-Se areas. In this study, Se accumulator, Brassica juncea (Indian mustard), was tested for its capacity to extract Se from naturally seleniferous soil (~8 mg Se kg-1 of soil) collected from west Fort Collins, CO, USA. Two Se-tolerant bacterial consortia (G1 and G2, 4–5 bacterial strains in each) were tested for their effects on plant growth and Se accumulation. B. juncea accumulated Se to 711 mg kg-1 dry weight (DW) in leaves, 276 mg kg-1 DW in pod husk and 358 mg kg-1 DW in seeds. Plants inoculated with consortium G1 showed significantly increased growth (dry biomass, seed weight) compared to control plants and G2-inoculated plants. G2-Inoculated plants showed reduced photosynthesis and stomatal conductance compared to control plants and G1-inoculated plants, as well as reduced Se accumulation in leaf and seed tissues. Sulfur levels were not affected by inoculation. Non-protein thiol levels were significantly elevated in G2-inoculated plants. In conclusion, B. juncea may be used to extract Se from seleniferous soil for the production of Se-enriched plant material, and inoculation with bacterial consortium G1 further enhances the efficiency of this process by stimulating plant growth.

Se-enriched sprouted seeds as functional additives in sourdough fermentation

Sprouted seeds possess potential to stimulate the growth and acidifying activity of lactic acid bacteria. Simultaneous enrichment of the sprouted seeds in deficient selenium may create a multifunctional additive to sourdough fermentation with consequent supplementation of human diet. Bread being a staple diet seems to be a perfect carrier of this micronutrient.In the study germinating seeds revealed high ability to accumulate selenium from watering solution, up to 188 mg Se/kg of dried sprouts in the case of lentil. The process of selenium accumulation strongly depended on the plant species resulting in total Se content in soy and lentil biomass twice as high as in rye or wheat sprouts. A high correlation (R2 = 0.97) between selenium concentration in water and Se accumulation in biomass was observed. Raising of pH from 7.0 to 8.0 increased 2.5 times selenium uptake.The addition of Se-enriched plant biomass had stimulating effect on the sourdough fermentation process allowing to shorten it by 8–16 h, depending on the dose and temperature. Se fortified rye sprouts used in amounts 2.5 g/100 g of flour did not deteriorate sensory quality of bread and raised five times selenium content in it.

Advances in the study of genetic enrichment of selenium in plants

Selenium (Se) is a micronutrient essential for human and animal health. Due to the unbalanced distribution of Se resources in the world, Se deficiency is regarded as a major human health problem. Insufficient ingestion of Se in human caused a series of disease including Keshan disease and Kashin-Beck's disease. While some parts of the world was Se poisoning due to the Se ores on geological stratification or Se pollution. The using Se-enriched and/or hyperaccumulated green plants to treat these problems has acquired more and more attention worldwide from last decade. This paper describes current advances in the efforts of searching Se enriched plant genetic resources, clarifying the Se metabolism and accumulation mechanism in plants, and cloning key genes responsible for Se accumulation or hyper-accumulation and their transformation in plants.

SELENIUM AND SULFUR INCREASE SULFUR UPTAKE AND REGULATE GLUCOSINOLATE METABOLISM IN BRASSICA OLERACEA

Selenium in soils can result in increased uptake of S and a reduction in glucosinolates in Brassica species. Rapid cycling B. oleracea plants were grown hydroponically in nutrient solution with Se treatments delivered as sodium selenate in concentrations of 0.0, 0.5, 0.75, 1.0 and 1.5 ppm. Elevated S treatments of 37 ppm sulfate and 37 ppm sulfate/ 0.75 ppm selenate were incorporated to compare with Se treatments. Se concentration in the nutrient solution was positively correlated with Se and S uptake in the plants. The S concentration of plants exposed to Se was equal to or greater than the S concentration of plants exposed to elevated S in the nutrient solution. In spite of higher S concentrations, there was a decrease in production of 5 of the 7 glucosinolates analyzed in Se enriched plants. Plants in elevated S treatments had higher glucosinolate production than Se treated plants. These results suggest that Se either up-regulates or prevents the down-regulation of S uptake in B. oleracea. In addition, Se's presence within the plant seems to have a negative impact on the production of certain glucosinolates despite adequate availability of S.

Biotransfer Possibilities of Selenium from Plants Used in Phytoremediation

ABSTRACT We are investigating the biotransfer of accumulated Se by the plant in several phytoremediation systems. In study I, we evaluated the biotransfer of Se from Indian mustard, a Brassica species, to the insect-cabbage looper (Trichoplusia ni); mortality, deterrence, and biomagnification of Se were examined. We determined that feeding behavior of food chain consumers was affected not only by the plant concentration of Se, but also by the mobility of the insects and choice of feed available. In study II, we examined the survival and development of beet army worm (Spodoptera exigua) fed Se-enriched plant tissues from different lines of saltbush (Atriplex spp.) After feeding on lines of saltbush that produced high biomass and accumulated high concentrations of Se, insect growth and survival was reduced. In studies III, IV, and V, lambs, dairy cows, and rabbits were fed Se-enriched Brassica and Medicago (alfalfa) plants as part of their feed ration. None of the tested animals exhibited any Se toxicity symptoms, but they had increased levels of Se in most tissues sampled (e.g., organs, blood, urine, feces), excluding milk. In study VI, we evaluated biotransfer of Se from broccoli to rats to determine efficacy of Se for reducing colon cancer. We found that Se-enriched plant material was more effective than inorganic sources of Se for preventing precancerous colon lesions. Results from all studies clearly show that Se absorbed by plants can be transferred biologically in an intentional or unintentional manner to insects and animals.

The Search for Anticarcinogenic Organoselenium Compounds from Natural Sources

ABSTRACT: Consumption of Se-enriched plants or yeast-based nutritional supplements is reported to reduce the risk of cancer. Separation and identification of natural organoselenium compounds in these plants is essential to understand the basis for their biological activity. Earlier work suggests that plants convert inorganic selenium in the soil or growth medium into organoselenium compounds, such as selenoamino acids, following a route similar to the sulfur assimilatory pathway. To separate and detect selenoamino acids in plant extracts, we employ ion pair LC with an inductively coupled plasma mass spectrometer (ICP-MS) detector and capillary GC with an atomic emission detector (AED), for underivatized and derivatized compounds, respectively. Volatile selenium compounds, such as those found in human garlic breath, have been analyzed using GC-AED. Results involving Se-enriched garlic and yeast-based nutritional supplements are presented.