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Abstract Background Selenium nanoparticles (SeNPs) are increasingly gaining attention due to its characteristics of low toxicity, high activity, and stability. Additionally, Bacillus licheniformis, as a probiotic, has achieved remarkable research outcomes in diverse fields such as medicine, feed processing, and pesticides, attracting widespread attention. Consequently, evaluating the activity of probiotics and SeNPs is paramount. The utilization of probiotics to synthesize SeNPs, achieving large-scale industrialization, is a current hotspot in the field of SeNPs synthesis and is currently the most promising synthetic method. To minimize production costs and maximize yield of SeNPs, this study selected agricultural by-products that are nutrient-rich, cost-effective, and readily available as culture medium components. This approach not only fulfills industrial production requirements but also mitigates the impact on downstream processes. Results The experimental findings revealed that SeNPs synthesized by B. licheniformis F1 exhibited a spherical morphology with diameters ranging from 110 to 170 nm and demonstrating high stability. Both the secondary metabolites of B. licheniformis F1 and the synthesized SeNPs possessed significant free radical scavenging ability. To provide a more robust foundation for acquiring large quantities of SeNPs via fermentation with B. licheniformis F1, key factors were identified through single-factor experiments and response surface methodology (RSM) include a 2% seed liquid inoculum, a temperature of 37 ℃, and agitation at 180 rpm. Additionally, critical factors during the optimization process were corn powder (11.18 g/L), soybean meal (10.34 g/L), and NaCl (10.68 g/L). Upon validating the optimized conditions and culture medium, B. licheniformis F1 can synthesize nearly 100.00% SeNPs from 5 mmol/L sodium selenite. Subsequently, pilot-scale verification in a 5 L fermentor using the optimized medium resulted in a shortened fermentation time, significantly reducing production costs. Conclusion In this study, the efficient production of SeNPs by the probiotic B. licheniformis F1 was successfully achieved, leading to a significant reduction in fermentation costs. The exploration of the practical applications of this strain holds significant potential and provides valuable guidance for facilitating the industrial-scale implementation of microbial synthesis of SeNPs.

Chestnuts, despite their nutritional value, pose challenges in starch processing, digestion, and absorption. This study employed various color-fixing formulations and processing methods to simulate the in vitro digestion of both untreated and enzymatically hydrolyzed chestnut flour. Changes in starch properties, digestion characteristics, and estimated glycemic index (eGI) were analyzed to understand how enzymatic hydrolysis affects chestnut flour properties. The results showed that the browning of chestnut flour was the least when the mass ratio of vitamin C, citric acid, and EDTA-Na2 was 9:1:0.3. Following treatment with pullulanase and glucoamylase, the content of rapidly digestible starch decreased to 10 %, while the content of slowly digestible starch and resistant starch increased to 62 % and 27 %, respectively. The eGI value of chestnut flour after enzymatic hydrolysis increased to 61.85–65.14, the hydrolysis rate was 78.37 %–89.20 %, the water holding capacity was 5.3–8.6, the solubility was 51.33 %–58.33 %, and the swelling degree decreased to 2.21–3.33 mL/g.

Selenium nanoparticles (SeNPs) have greater bioavailability and safety than inorganic selenium, and was widely used in medical, agricultural, nutritional supplements, and antibacterial fields. The present study screened a strain L11 producing SeNPs from a selenium rich dairy cow breeding base in Hubei Province, China. The strain was identified as Bacillus subtilis through physiological, biochemical, and molecular biology analysis. By adjusting the cultivation conditions, the experiment determined the ideal parameters for L11 to efficiently produce SeNPs. These parameters include a pH value of 6, a cultivation temperature of 37 °C, a concentration of 4 mmol/L Na2SeO3, and a cultivation of 48 h. X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), and Transmission Electron Microscopy (TEM) were used to verify that the Se particles produced by L11 are SeNPs with diameters ranging from 50 to 200 nm. The combination of the protein analysis of different cell components and TEM analysis showed that L11 mainly produces SeNPs through the transformation of the cell’s periplasmic space, cell membrane, and cell wall. Adding the L11 SeNPs complex to sheep feed can significantly enhance the antioxidant activity and immunity of sheep, and increase the Se content in the neck muscles, liver, and spleen tissues.

Moderate amounts of Se can promote crop growth, enhance stress resistance, increase yield, and improve nutritional quality. In the present study, kudzu seedlings were used as experimental materials, and their physiological indicators, antioxidant activity, nutritional components, and flavonoid content were measured after being treated with Na2SeO3 hydroponics. Transcriptome sequencing analysis was used to reveal the relevant genes involved in regulating the effects of exogenous Se on the content of Se-compounds and flavonoids in kudzu. The results indicated that treatment with 20 mg/L Na2SeO3 significantly increased stem and root lengths, dry and fresh weight, lateral root development, and chlorophyll b content. However, at higher concentrations (30–40 mg/L), lateral root abundance and chlorophyll levels decreased. Na2SeO3 treatment also augmented the antioxidant capacity and enhanced the content of major nutrients in kudzu seedlings. The total Se content in kudzu escalated with increasing Na2SeO3 concentration, with selenomethionine emerging as the primary organic-Se species. After treatment with Na2SeO3, the content of puerarin in both aboveground and underground parts decreased, while the content of total flavonoids increased. Daidzin increased in the roots. Differential expression gene analysis revealed that genes such as TRXB2, SYM, MMT1, and METE were involved in Se uptake and transformation in kudzu, while bZIP43 and WRKY47 played a role in flavonoid biosynthesis.

Abstract 4‐Coumarate‐CoA ligase (4CL) gene plays vital roles in plant growth and development, especially the regulation of lignin metabolism and flavonoid synthesis. To investigate the potential function of 4CL in the lignin biosynthesis of Ginkgo biloba, this study identified two 4CL genes, Gb4CL1 and Gb4CL2, from G. biloba genome. Based on the phylogenetic tree analysis, Gb4CL1 and Gb4CL2 protein were classified into Class I, which has been confirmed to be involved in lignin biosynthesis. Therefore, it can be inferred that these two genes may also participate in lignin metabolism. The tissue‐specific expression patterns of these two genes revealed that Gb4CL1 was highly expressed in microstrobilus, whereas Gb4CL2 was abundant in immature leaves. The onion transient expression assay indicated that Gb4CL1 was predominantly localized in the nucleus, indicating its potential involvement in nuclear functions, while Gb4CL2 was observed in the cell wall, suggesting its role in cell wall‐related processes. Phytohormone response analysis revealed that the expression of both genes was upregulated in response to indole acetic acid, while methyl jasmonate suppressed it, gibberellin exhibited opposite effects on these genes. Furthermore, Gb4CL1 and Gb4CL2 expressed in all tissues containing lignin that showed a positive correlation with lignin content. Thus, these findings suggest that Gb4CL1 and Gb4CL2 are likely involved in lignin biosynthesis. Gb4CL1 and Gb4CL2 target proteins were successfully induced in Escherichia coli BL21 with molecular weights of 85.5 and 89.2 kDa, proving the integrity of target proteins. Our findings provided a basis for revealing that Gb4CL participated in lignin synthesis in G. biloba.

Air pollution exhibits significant spatial spillover effects, complicating and challenging regional governance models. This study innovatively applied and optimized a statistics-based complex network method in atmospheric environmental field. The methodology was enhanced through improvements in edge weighting and threshold calculations, leading to the development of an advanced pollutant transport network model. This model integrates pollution, meteorological, and geographical data, thereby comprehensively revealing the dynamic characteristics of PM2.5 and O3 transport among various cities in China. Research findings indicated that, throughout the year, the O3 transport network surpassed the PM2.5 network in edge count, average degree, and average weighted degree, showcasing a higher network density, broader city connections, and greater transmission strength. Particularly during the warm period, these characteristics of the O3 network were more pronounced, showcasing significant transport potential. Furthermore, the model successfully identified key influential cities in different periods; it also provided detailed descriptions of the interprovincial spillover flux and pathways of PM2.5 and O3 across various time scales. It pinpointed major pollution spillover and receiving provinces, with primary spillover pathways concentrated in crucial areas such as the Beijing-Tianjin-Hebei (BTH) region and its surrounding areas, the Yangtze River Delta, and the Fen-Wei Plain. Building on this, the model divided the O3, PM2.5, and synergistic pollution transmission regions in China into 6, 7, and 8 zones, respectively, based on network weights and the Girvan Newman (GN) algorithm. Such division offers novel perspectives and strategies for regional joint prevention and control. The validity of the model was further corroborated by source analysis results from the WRF-CAMx model in the BTH area. Overall, this research provides valuable insights for local and regional atmospheric pollution control strategies. Additionally, it offers a robust analytical tool for research in the field of atmospheric pollution.

Human activities, such as mining, industrialization, industrial waste emissions, and agricultural practices, have caused heavy metals to become widespread and excessively accumulated in soil. The high concentrations of heavy metals in soil can be toxic to plants, severely affecting crop yield and quality. Moreover, these heavy metals can also enter the food chain, affecting animals and humans and leading to various serious illnesses. Selenium (Se) is not only an essential element for animals and humans but is also beneficial for plants, as it promotes their ability to respond actively to biotic and abiotic stresses. The global issue of Se deficiency in diets has made plants the primary source for human Se supplementation. This paper comprehensively reviews the effects of heavy metal stress on plant growth and development, physiological responses of plants to such stress, and the intracellular transport processes of heavy metals within plants. It particularly focuses on the mechanisms by which Se alleviates heavy metal stress in plants. Additionally, the study delves into how Se significantly enhances plant tolerance mechanisms against typical heavy metals, such as cadmium (Cd), lead (Pb), and mercury (Hg). This integrative research not only expands the boundaries of research in the field of plant heavy metal stress and Se application but also provides new perspectives and solutions for understanding and addressing complex environmental heavy metal pollution issues. By integrating these aspects, this paper not only fills existing gaps in the literature but also offers comprehensive scientific basis and strategic recommendations for environmental protection and sustainable agriculture development.

Abstract Terpenoids are the main active components in the Zanthoxylum armatum leaves, which have extensive medicinal value. The Z. armatum leaf is the main by‐product in the Z. armatum industry. However, the transcription factors involved in the biosynthesis of terpenoids are rarely reported. This study was performed to identify and classify the APETALA2/ethylene‐responsive factor (AP2/ERF) gene family of Z. armatum. The chromosome distribution, gene structure, conserved motifs, and cis‐acting elements of the promoter of the species were also comprehensively analyzed. A total of 214 ZaAP2/ERFs were identified. From the obtained transcriptome and terpenoid content data, four candidate ZaAP2/ERFs involved in the biosynthesis of terpenoids were selected via correlation and weighted gene co‐expression network analysis. A phylogenetic tree was constructed using 13 AP2/ERFs related to the biosynthesis of terpenoids in other plants. ZaERF063 and ZaERF166 showed close evolutionary relationships with the ERFs in other plant species and shared a high AP2‐domain sequence similarity with the two closest AP2/ERF proteins, namelySmERF8 from Salvia miltiorrhiza and AaERF4 from Artemisia annua. Further investigation into the effects of methyl jasmonate (MeJA) treatment on the content of terpenoids in Z. armatum leaves revealed that MeJA significantly induced the upregulation of ZaERF166 and led to a significant increase in the terpenoids content in Z. armatum leaves, indicating that ZaERF166 might be involved in the accumulation of terpenoids of Z. armatum. Results will be beneficial for the functional characterization of AP2/ERFs in Z. armatum and establishment of the theoretical foundation to increase the production of terpenoids via the manipulation of the regulatory elements and strengthen the development and utilization of Z. armatum leaves.

Enzymatically derived selenium-enriched peptides from Cardamine violifolia (CV) can serve as valuable selenium supplements. However, the industrial application of free enzyme is impeded by its limited stability and reusability. Herein, this study explores the application of co-immobilized enzymes (Alcalase and Dispase) on amino resin for hydrolyzing CV proteins to produce selenium-enriched peptides. The successful enzyme immobilization was confirmed through scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and Fourier-transform infrared spectroscopy (FTIR). Co-immobilized enzyme at a mass ratio of 5:1 (Alcalase/Dispase) exhibited the smallest pore size (7.065 nm) and highest activity (41 U/mg), resulting in a high degree of hydrolysis of CV protein (27.2%), which was obviously higher than the case of using free enzymes (20.7%) or immobilized Alcalase (25.8%). In addition, after a month of storage, the co-immobilized enzyme still retained a viability level of 41.93%, showing fairly good stability. Encouragingly, the selenium-enriched peptides from co-immobilized enzyme hydrolysis exhibited uniform distribution of selenium forms, complete amino acid fractions and homogeneous distribution of molecular weight, confirming the practicality of using co-immobilized enzymes for CV protein hydrolysis.

Acting as a growth regulator, Indole-3-acetic acid (IAA) is an important phytohormone that can be produced by several Bacillus species. However, few studies have been published on the comprehensive evaluation of the strains for practical applications and the effects of selenium species on their IAA-producing ability. The present study showed the selenite reduction strain Bacillus altitudinis LH18, which is capable of producing selenium nanoparticles (SeNPs) at a high yield in a cost-effective manner. Bio-SeNPs were systematically characterized by using DLS, zeta potential, SEM, and FTIR. The results showed that these bio-SeNPs were small in particle size, homogeneously dispersed, and highly stable. Significantly, the IAA-producing ability of strain was differently affected under different selenium species. The addition of SeNPs and sodium selenite resulted in IAA contents of 221.7 µg/mL and 91.01 µg/mL, respectively, which were 3.23 and 1.33 times higher than that of the control. This study is the first to examine the influence of various selenium species on the IAA-producing capacity of Bacillus spp., providing a theoretical foundation for the enhancement of the IAA-production potential of microorganisms.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by the deposition of β-amyloid (Aβ) peptides and dysfunction of mitochondrion, which result in neuronal apoptosis and ultimately cognitive impairment. Inhibiting Aβ generation and repairing mitochondrial damage are prominent strategies in AD therapeutic treatment. Luteolin, a flavonoid compound, exhibits anti-inflammatory neuroprotective properties in AD mice. However, it is still unclear whether luteolin has any effect on Aβ pathology and mitochondrial dysfunction. In this study, the beneficial effect and underlying mechanism of luteolin were investigated in triple transgenic AD (3 × Tg-AD) mice and primary neurons. Our study showed that luteolin supplement significantly ameliorated memory and cognitive impairment of AD mice and exerted neuroprotection by inhibiting Aβ generation, repairing mitochondrial damage and reducing neuronal apoptosis. Further research revealed that luteolin could directly bind with peroxisome proliferator-activated receptor gama (PPARγ) to promote its expression and function. In the culture of hippocampus-derived primary neurons, addition of PPARγ antagonist GW9662 or knockdown of PPARγ with its siRNA could eliminate the effect of luteolin on AD pathologies. In summary, this work revealed for the first time that luteolin effectively improved cognitive deficits of 3 × Tg-AD mice and inhibited Aβ-induced oxidative stress, mitochondrial dysfunction and neuronal apoptosis via PPARγ-dependent mechanism. Hence, luteolin has the potential to serve as a therapeutic agent against AD.

Nano-selenium (Selenium nanoparticles, SeNPs) has unique properties and potential applications in the fields of food, medicine, pharmacology and agriculture. Polysaccharide is a natural biopolymer, which is considered to be the most promising carrier for the synthesis of SeNPs due to its excellent biocompatibility and biodegradability. This article summarizes the research progress in the synthesis of SeNPs using polysaccharides as templates. The effects of different types of polysaccharides and different synthesis conditions on the properties of polysaccharide-selenium nanoparticles composites are also discussed. Finally, the applications of these composites in anti-tumor are introduced, which provides new ideas in constructing SeNPs system using polysaccharides as carriers and further promotes their applications in the fields of medicine and food.

Myofibrillar protein as a structural protein with important biological functions in muscle, can form a gel alone or as the main part of a gel. The gelling mechanism and gel properties of MP have attracted much attention in meat science research. It is important to clarify the effects of various additives on the quality of meat product, thus providing references for the development of healthy low-fat meat products. Polysaccharides are widely used to improve the quality of meat products because of their good biocompatibility, wide sources, and low prices. This review introduces the definition, classification and functional properties of polysaccharides and summarizes the effects of polysaccharides on the gel properties of MP. Furthermore, the applications of polysaccharides in meat products are discussed, which provides theoretical basis for the production of low-fat meat products. Finally, the prospects and challenges associated with low-fat meat products are proposed.

Oxidative stress occurs in the process of egg storage. Antioxidants as feed additives can enhance egg quality and extend the shelf life of eggs. Selenium-enriched Cardamine violifolia (SEC) has strongly antioxidant properties. The objective of this study was to assess the effects of dietary supplementation with SEC on egg quality and the yolk antioxidant capacity of eggs stored at 4 °C and 25 °C. Four hundred fifty 65-week-old, Roman hens that were similar in laying rate (90.79 ± 1.69%) and body weight (2.19 ± 0.23 kg) were divided into 5 groups. The birds were fed diets supplemented with 0 mg/kg selenium (Se) (CON), 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se for selenium-enriched Cardamine violifolia (SEC) or 0.3 mg/kg Se from Se-enriched Cardamine violifolia and 0.3 mg/kg Se from Se-enriched yeast (SEC + SEY) for 8 weeks. The eggs were collected on the 8th week and were analyzed for egg quality and oxidative stability of yolk during storage at 4 °C or 25 °C for 0, 2, 4, or 6 weeks. Dietary SEC and SEC + SEY supplementation increased the Haugh unit (HU) and albumen foam stability in eggs stored at 4 °C and 25 °C (p < 0.05). SS and SEC supplementation increased the yolk index in eggs stored at 25 °C (p < 0.05). SEC or SEC + SEY slowed down an increase in albumen pH and gel firmness in eggs stored at 4 °C and 25 °C (p < 0.05). Moreover, SEC or SEC + SEY alleviated the increase in malonaldehyde (MDA), and the decrease in total antioxidant capacity (T-AOC) level and total superoxide dismutase (T-SOD) activity in yolks stored at 4 °C and 25 °C (p < 0.05). These results indicate that SEC mitigated egg quality loss and improved the antioxidant capacity of yolks during storage. SEC supplementation would be advantageous to extend the shelf life of eggs.

Selenium (Se) is an essential trace element for the human body, and its dietary deficiency has been a widespread issue globally. Vegetables serve as a significant source of dietary Se intake, with organic Se derived from plants being safer than inorganic Se. In the present study, Taraxacum mongolicum plants were treated with various concentrations of Na2SeO3. The results showed that as the concentration of Na2SeO3 increased, the chlorophyll content of dandelion seedlings decreased at high concentrations, and the content of soluble sugars, soluble proteins, flavonoids, total phenols, and Vc all increased. The application of Na2SeO3 at concentrations ranging from 0 to 4 mg/L resulted in a reduction in plant malondialdehyde content and an enhancement in the activity of antioxidant enzymes. Following the Na2SeO3 treatment, five Se species were identified in the seedlings, Se4+, Se6+, selenocysteine, selenomethionine, and methylselenocysteine. Notably, selenomethionine emerged as the primary organic Se species in the shoots of dandelion. Transcriptome analysis revealed that ABC11b, PTR4, MOCOS, BAK1, and CNGC1 were involved in the absorption, transport, and storage of Se in dandelion, and C7317 was involved in the scavenging of reactive oxygen species. This study complements the understanding of the possible molecular mechanisms involved in the absorption and transformation of organic Se by plants, thereby providing a theoretical foundation for the biofortification of dandelion with Se in crops.

A novel alternative to prepare the inulin-procyanidin complex assisted by pulsed electric field (PEF) treatment was explored in this study. Results showed that the optimal condition of PEF treatment enhanced the adsorption rate of procyanidins to inulin from 78.56 to 103.46 μg/mg. Based on well fitted by Redlich-Peterson model and spectral analysis including UV and FT-IR, the interaction between inulin and procyanidin was evidenced to be dominated by hydrogen bonds. The DSC curve and the SEM spectrum displayed better stability of the PEF-treated inulin-procyanidin complex than the untreated complex. The PEF-treated complex had lower solubility but higher water-holding capacity than inulin, which exhibited stronger shear-thinning property and more stable flow behavior referring to rheological analysis. Furthermore, the gel formed from the PEF-treated complex possessed greater hardness, chewiness and viscosity, with no significant effects noted in terms of springiness, cohesiveness and resilience.

Cardamine violifolia, a species belonging to the Brassicaceae family, is a novel vegetable crop that is rich in glucosinolates. However, the specific glucosinolate profiles in this species remain unknown. In the present study, four parts of C. violifolia were collected including central leaves (CLs), outer leaves (OLs), petiole (P), and root (R). The highest level of total glucosinolate was observed in the R. A total of 19 glucosinolates were found in C. violifolia. The predominant glucosinolate compounds were 3-methylbutyl glucosinolate, 6-methylsulfinylhexyl glucosinolate, Indol-3-ylmethyl glucosinolate, 4-methoxyglucobrassicin, and neoglucobrassicin. A transcriptome analysis showed that 16 genes, including BCAT1, BCAT3-6, CYP79A2, CYP79B2-3, CYP83A1, CYP83B1, and SOT17-18, and nine metabolites, such as valine, tryptophan, and 1-methylpropyl glucosinolate, were enriched in the glucosinolate biosynthesis pathway. These genes may be involved in the regulation of glucosinolate accumulation among the four parts. A weighted gene co-expression analysis showed that five genes were predicted to regulate glucosinolate accumulation, including ABC transporter G family member 19, 3-ketoacyl-CoA synthase 19, and pyruvate decarboxylase 1. This study deepens our understanding of the nutrient quality of C. violifolia and provides insights into the regulatory mechanism of glucosinolate accumulation in C. violifolia.

This study was conducted to evaluate the effects of different Selenium (Se) sources on growth performance, intestinal function and antioxidant status of weaned piglets. A total of 300 weaned pigs were randomly allocated to 5 treatment groups with 5 replicates of 12 pigs/pen. The control group was corn-soybean basal diet without any additional Se supplement. The experimental diets were supplemented with 0.3 mg/kg of Se from sodium selenite (SS), Se-enriched yeast (SEY), Se-enriched Cardamine violifolia (SEC) and 0.3+0.3 mg/kg of Se from SEY and SEC, respectively. The trial lasted for 4 weeks. The results showed that diets supplementation with SEY, SEC or SEY+SEC could improve average daily gain and reduce feed/gain ratio during the entire study. Compared with the control group, SEC or SEY+SEC improved intestinal morphology, indicated by greater villus height and villus height/ crypt depth ratio. In addition, SEC or SEY+SEC also increased maltase and lactase activities as well as tight junction protein expression. Different Se sources decreased malondialdehyde (MDA) concentration and improved superoxide dismutase (SOD) activity in serum. In the jejunum, SEY or SEC reduced MDA concentration and increased total antioxidant capacity (T-AOC) compared with the control group. Moreover, SEY+SEC increased the antioxidant parameters including SOD and T-AOC in the jejunum. Dietary SEY or SEC supplementation significantly increased the mRNA expression of selenoproteins including thioredoxin reductase 1 (TXNRD1), selenoprotein I (SELENOI), selenoprotein S (SELENOS), and selenoprotein P (SELENOP) in the jejunum. In conclusion, organic Se sources, especially Cardamine violifolia, improve growth performance, potentially by regulating intestinal function, antioxidant capacity and selenoprotein expression in piglets.

BackgroundCardamine violifolia (Cv) is a kind of selenium-enriched plant which contains high levels of organic selenium (Se) such as selenocysteine and methylselenocysteine. This study was conducted to investigate the effects of this new source of Se on the growth performance, anti-oxidative capacity and meat quality in broilers compared with other frequently-used Se sources.MethodsA total of 240 broilers were allotted into 4 treatments: (1) Control group (Se free diets, CON); (2) Sodium selenite group (0.3 mg/kg Se sourced from Na2SeO3 diets, SeNa); (3) Selenium yeast group (0.3 mg/kg Se sourced from Se-Yeast diets, SeY); (4) Plant Se group (0.3 mg/kg Se sourced from Cv diets, SeCv). The whole study lasted 42 days and was divided into 2 stages (1–21 d as earlier stage and 22–42 d as later stage).ResultsThe results showed that the broilers fed SeCv diets had improved average daily gain and the ratio of feed to gain compared to the broilers fed SeNa and SeY diets during the earlier stage. However, there was no significant difference in growth performance of broilers fed these 3 sources of Se diets during the whole period. The broilers fed SeCv diets had improved intestinal mucosal morphology on d 21 and 42. Enhanced liver total anti-oxidative capacity was observed from the broilers fed SeCv diets compared with the other 2 Se sources diets on d 21. Furthermore, lower liver malondialdehyde contents were determined from the broilers fed SeCv and SeY diets compared with SeNa diets. At last, the broilers fed SeCv had increased redness in thigh muscle and decreased cooking loss in both breast and thigh muscle compared with the boilers fed SeNa diets. However, the broilers had similar meat quality between SeCv group and SeY group.ConclusionIn conclusion, these results demonstrated that SeCv was a well-organic Se source for broilers.

It is an essential method for healthy Selenium (Se) supplementation to convert exogenous Se into organic Se via crops. Brassica juncea (L.) Czern (leaf mustard) was employed as plant material in this investigation and was treated with sodium selenite (Na2SeO3). Its physiological indicators, nutritional quality, antioxidant enzyme activity, total Se content, and Se morphology were all evaluated. The absorption, transportation, and transformation mechanisms of Se in mustard were studied using transcriptome data. The results revealed that low concentration of Se treatment promoted the growth of mustard, while high concentration Se treatment inhibited it. The concentration of 10 mg/L Na2SeO3 treatment had the best growth parameters for mustard. Compared to the control group, the content of vitamin C (Vc) and anthocyanins in the treatment group increased to varying degrees, while the content of flavonoids, total phenols, soluble sugar, and soluble protein increased first and then decreased. Five Se forms, Se (IV), Se (VI), selenocystine(SeCys2), selenomethionine (SeMet), and methylselenocysteine (MeSeCys), were detected in the Na2SeO3 treatment group, with organic Se accounting for over 95%. Na2SeO3 treatment can significantly reduce the accumulation of ROS in mustard plants and enhance their stress resistance. Transcriptome data and metabolite association analysis showed that PHO1-H8 promoted the absorption of Na2SeO3 by mustard roots, while SULTR3;3 and SULTR4;1 promoted the transport of Se from roots to the aboveground portion and chloroplasts. Se in mustard was transformed into SeMet, SeCys, MeSeCys, and selenoprotein through the action of genes such as APS, APR, and SEP1, and stored in plant leaves.

Cadmium (Cd) is a common agricultural soil pollutant, which does serious harm to the environment and the human body. In this study, Brassica juncea was treated with different concentrations of CdCl2 and Na2SeO3. Then, physiological indexes and transcriptome were measured to reveal the mechanisms by which Se reduces the inhibition and toxicity of Cd in B. juncea. The results showed that Se alleviated the inhibitive Cd effects on seedling biomass, root length, and chlorophyll, and promoted the adsorption of Cd by pectin and lignin in the root cell wall (CW). Se also alleviated the oxidative stress induced by Cd, and reduced the content of MDA in cells. As a result, SeCys and SeMet alleviated the transport of Cd to the shoots. Transcriptome data showed that the bivalent cation transporter MPP and ABCC subfamily participated in the separation of Cd in vacuoles, CAL1 was related to the chelation of Cd in the cytoplasm of cells, and ZIP transporter 4 reduced the transport of Cd to the shoots. These results indicated that Se alleviated the damage of Cd in plants and decreased its transport to the shoots by improving the antioxidant system, enhancing the ability of the CW to adsorb Cd, reducing the activity of Cd transporters, and chelating Cd.

Accurate identification of source information (i.e., source strength and location) is crucial for the air pollution control or effective accidental response. Optimization inversion based on bio-inspired algorithms (BIOs) is an effective method for estimating source information. However, the impacts of different BIOs and the shared parameter of population size in BIOs on source inversion performance have not been revealed. Here the source inversion performance (i.e., accuracy and robustness) of six typical BIOs [i.e., bacterial foraging optimization algorithm (BFO), chicken swarm optimization algorithm (CSO), differential evolution algorithm (DE), genetic algorithm (GA), particle swarm optimization (PSO), and seeker optimization algorithm (SOA)], and their population sizes are evaluated based on the Prairie Grass dataset which covering different atmospheric conditions (i.e., Pasquill stability classes A, B, C, D, E, and F). Results indicated the population size has substantial influence on source inversion. The accuracy of all BIOs in source strength fluctuated greatly when the population size was small, whereas, tended to be stable as the population size increased. Overall, the BFO had the best accuracy with lowest deviations (74.5% for source strength and 29.7 m for location parameter x0), whereas SOA had the best robustness for all source parameters. Atmospheric conditions indicated an obvious influence on the inversion performance of the BIOs. The BFO and CSO performed the best with the lowest deviations [137.5 and 26.7% for unstable conditions (A, B, and C) and stable condition (E), respectively], all algorithms are comparable (67.4 ± 2.1%) in neutral condition (D), and BFO and CSO had the comparable performances (23.2 and 24.3%) and performed better under extremely stable condition (F). This study enhances the understanding of the factors influencing source inversion and provides a reference for the selection of appropriate bio-inspired algorithms and the reasonable setting of population size parameter for source inversion in practical environmental management.

Abstract Background Cardamine violifolia, native to China, is one of the selenium (Se) hyperaccumulators. The mechanism of Se metabolism and tolerance remains unclear, and only limited genetic information is currently available. Therefore, we combined a PacBio single-molecule real-time (SMRT) transcriptome library and the Illumina RNA-seq data of sodium selenate (Na2SeO4)-treated C. violifolia to further reveal the molecular mechanism of Se metabolism. Results The concentrations of the total, inorganic, and organic Se in C. violifolia seedlings significantly increased as the Na2SeO4 treatment concentration increased. From SMRT full-length transcriptome of C. violifolia, we obtained 26,745 annotated nonredundant transcripts, 14,269 simple sequence repeats, 283 alternative splices, and 3407 transcription factors. Fifty-one genes from 134 transcripts were identified to be involved in Se metabolism, including transporter, assimilatory enzyme, and several specific genes. Analysis of Illumina RNA-Seq data showed that a total of 948 differentially expressed genes (DEGs) were filtered from the four groups with Na2SeO4 treatment, among which 11 DEGs were related to Se metabolism. The enrichment analysis of KEGG pathways of all the DEGs showed that they were significantly enriched in five pathways, such as hormone signal transduction and plant-pathogen interaction pathways. Four genes related to Se metabolism, adenosine triphosphate sulfurase 1, adenosine 5′-phosphosulfate reductase 3, cysteine (Cys) desulfurase 1, and serine acetyltransferase 2, were regulated by lncRNAs. Twenty potential hub genes (e.g., sulfate transporter 1;1, Cys synthase, methionine gamma-lyase, and Se-binding protein 1) were screened and identified to play important roles in Se accumulation and tolerance in C. violifolia as concluded by weighted gene correlation network analysis. Based on combinative analysis of expression profiling and annotation of genes as well as Se speciation and concentration in C. violifolia under the treatments with different Na2SeO4 concentrations, a putative Se metabolism and assimilation pathway in C. violifolia was proposed. Conclusion Our data provide abundant information on putative gene transcriptions and pathway involved in Se metabolism of C. violifolia. The findings present a genetic resource and provide novel insights into the mechanism of Se hyperaccumulation in C. violifolia.

Source inversion is an effective approach for estimating air pollutant source parameters (e.g., source emission or source strength [Q0], source horizontal location [x0, y0], and release height [z0]) in industrial activities or accidents. Air pollution events in the real world generally correspond to complex application scenarios arising from unknown source parameters (i.e., Q0, [Q0, z0], [Q0, x0, y0], and [Q0, x0, y0, z0]) and atmospheric dispersion conditions. However, the source inversion characteristic law of these complex practical scenarios and the interaction mechanism between source location prior information and source strength inversion have not been revealed. In this study, the source inversion performance (accuracy and robustness) under the aforementioned scenarios was evaluated based on the Prairie Grass field experiments. Results indicated that the estimation accuracy of source strength was worse with an increase in the number of unknown source parameters with absolute relative deviations of 34.4, 46.0, 80.1, and 83.6% for a single parameter and double, triple, and quadruple parameters, respectively. Source strength inversion performance was obviously affected by location parameters; robustness was markedly reduced when source height was unknown, whereas accuracy was obviously reduced when source horizontal locations were unknown. Impacts of atmospheric conditions on different source parameters were distinct. Extreme atmospheric conditions (stability A and F) can obviously reduce the estimation accuracy of source strength for single and double parameter inversion scenarios, whereas unstable conditions (stability A, B, and C) can reduce the estimation accuracy of source strength for triple and quadruple parameter scenarios. Source inversion accuracy and robustness were generally poor under extremely stable conditions. This study can fill the knowledge gap in characteristic laws of source inversion under complex application scenarios and the interaction relationship between different unknown source parameters. The results of the influence law of location prior information on source strength inversion have important guiding significance to further improve the inversion accuracy of source strength in practical environmental managements.

Terpene trilactones (TTL) is a pharmacological ingredient in Ginkgo biloba and its content has become one of the key indices for medicinal value evaluation of ginkgo. 1-Deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) catalyzes the first step specific for isopentenyl diphosphate production in methylerythritol phosphate pathway, which provide the basic structure required for TTLs biosynthesis. To understand the mechanism controlling the GbDXR gene expression, the GbDXR promoter sequence was isolated and subjected to transient expression with the green fluorescent protein (GFP) in tobacco plants. Characteristic analysis revealed various cis-acting elements that related to light-regulated transcription, hormone signaling (auxin, ethylene), adversity stress and defense signaling (heat/dehydration stress) in the GbDXR promoter region. In transient expression assay, deletion of different portions of the upstream GbDXR promoter identified that the promoter region -3230bp to -865bp conserve the positive regulation function, which could promote the expression of GFP in the cytoplasm of tobacco leaf epidermal cells. The regulation function of the promoter region -865bp to -262bp remained to be elucidated. EMSA analysis suggested possible interactions of GbERF10 and GbERF17 with the ERF-binding elements in the upstream of GbDXR promoter. For abiotic stresses treatment, the expression of GbDXR gene could be significantly induced by UV-B and drought stress. In general, the GbDXR gene expressed differently in different ginkgo tissues but exhibited the highest transcriptional level in the root, with the maximum TTLs content simultaneously. The positive relationship between gene expression level and TTLs content indicated that the GbDXR is responsible for TTLs biosynthesis in G. biloba.

The authors wish to make the following corrections to their published paper [...]

Selenium (Se) is an important trace element in human and animal health. Approximately 0.5–1 billion people worldwide are facing Se deficiency which can result in various endemic diseases. Cabbage is one of the most popular vegetables and can accumulate Se through biofortification. Therefore, producing Se-enriched cabbage may be an effective method to alleviate Se deficiency. In this study, the effects of different concentrations of selenite application on the growth and nutritional quality of cabbage were investigated and the results showed that the growth of cabbage was promoted at low concentrations of selenite (0.1–0.4 mmol/L) but inhibited at high concentrations (0.8–1.6 mmol/L). Concentrations of 0.1–0.2 mmol/L of selenite induced the accumulation of primary metabolites (soluble proteins, soluble sugars, and free amino acids), representative secondary metabolites (ascorbic acid, glucosinolates, flavonoids, anthocyanins, and phenolic acids), and important antioxidant enzyme (glutathione peroxidase, catalase, and superoxide dismutase) activity to improve the nutritional quality of cabbages. In addition, a higher concentration (0.8–1.6 mmol/L) of selenite proved beneficial in the accumulation of total Se and representative organic Se in cabbages. The main organic Se species in cabbage were selenomethionine (SeMet), accounting for 12.10% of total Se, followed by selenocysteine (SeCys2), accounting for 2.96% of total Se. It is suggested that an appropriate dose of exogenous selenite could be selected for different production purposes in cabbage cultivation. These findings are helpful for us to deeply understand the effects of selenite on the growth and nutritional quality of cabbages and to provide reliable technical support for vegetable cultivation and Se biofortification.

The key to advancing urbanization is to promote the urban integration of numerous migrant workers. Two stages of decision making are involved for migrant workers, including residence (staying in cities) and settlement (transferring hukou into cities). The homestead is a necessity for migrant workers to keep their “peasant” status, which will further affect migrant workers’ identification with cities and influence their decision making towards urbanization. This paper uses data from the 2017 China Migrants Dynamic Survey (CMDS), through the coarsened exact matching (CEM) method and the analysis of mediation effects, to estimate how homesteads influence migrant workers’ urbanization intention and how the sense of identity serves as a mediator variable in this mechanism. Empirical results show that the ownership of homesteads is negatively correlated with migrant workers’ urbanization intention. Migrant workers with homesteads are 1.2% less likely to stay and 4.4% less likely to settle down in cities compared with their counterparts who do not have a homestead. In addition, identity plays a mediating role in the influence mechanism of homesteads on migrant workers’ urbanization intention. That is, the homestead has an indirect effect on migrant workers’ willingness to stay and settle down in cites through the sense of identity, aside from its direct effects. The mediation effect accounts for 20.87% of the total effect for willingness to stay and 25.63% of the total effect for willingness to settle down. This paper also represents how these coefficients vary by different regions and migration distances. Therefore, policymakers should provide institutional support for correctly guiding migrant workers to “abandon their land and enter the city” and strengthen their sense of identity to the city.

Selenium-enriched peptide (SP, selenopeptide) is an excellent organic selenium supplement that has attracted increasing attention due to its superior physiological effects. In this study, dextran–whey protein isolation–SP (DX-WPI-SP) microcapsules were fabricated via high-voltage electrospraying technology. The results of preparation process optimization showed that the optimized preparation process parameters were 6% DX (w/v), feeding rate Q = 1 mL/h, voltage U = 15 kV, and receiving distance H = 15 cm. When the content of WPI (w/v) was 4–8%, the average diameter of the as-prepared microcapsules was no more than 45 μm, and the loading rate for SP ranged from ~46% to ~37%. The DX-WPI-SP microcapsules displayed excellent antioxidant capacity. The thermal stability of the microencapsulated SP was improved, which was attributed to the protective effects of the wall materials for SP. The release performance was investigated to disclose the sustained-release capacity of the carrier under different pH values and an in-vitro-simulated digestion environment. The digested microcapsule solution showed negligible influence on the cellular cytotoxicity of Caco-2 cells. Overall, our work provides a facile strategy of electrospraying microcapsules for the functional encapsulation of SP and witnesses a broad prospect that the DX-WPI-SP microcapsules can exhibit great potential in the food processing field.

Selenium (Se) is an essential element for mammals, and its deficiency in the diet is a global problem. Agronomic biofortification through exogenous Se provides a valuable strategy to enhance human Se intake. Selenium nanoparticles (SeNPs) have been regarded to be higher bioavailability and less toxicity in comparison with selenite and selenate. Still, little has been known about the mechanism of their metabolism in plants. Soybean (Glycine max L.) can enrich Se, providing an ideal carrier for Se biofortification. In this study, soybean sprouts were treated with SeNPs, and a combination of next-generation sequencing (NGS) and single-molecule real-time (SMRT) sequencing was applied to clarify the underlying molecular mechanism of SeNPs metabolism. A total of 74,662 nonredundant transcripts were obtained, and 2109 transcription factors, 9687 alternative splice events, and 3309 long non-coding RNAs (lncRNAs) were predicted, respectively. KEGG enrichment analysis of the DEGs revealed that metabolic pathways, biosynthesis of secondary metabolites, and peroxisome were most enriched both in roots and leaves after exposure to SeNPs. A total of 117 transcripts were identified to be putatively involved in SeNPs transport and biotransformation in soybean. The top six hub genes and their closely coexpressed Se metabolism-related genes, such as adenylylsulfate reductase (APR3), methionine-tRNA ligase (SYM), and chloroplastic Nifs-like cysteine desulfurases (CNIF1), were screened by WGCNA and identified to play crucial roles in SeNPs accumulation and tolerance in soybean. Finally, a putative metabolism pathway of SeNPs in soybean was proposed. These findings have provided a theoretical foundation for future elucidation of the mechanism of SeNPs metabolism in plants.

As a selenium-enriched plant, Cardamine violifolia (SEC) has an excellent antioxidant function. The edibility of SEC is expected to develop new sources of organic Se supplementation for human and animal nutrition. This study was conducted to investigate the effects of SEC on laying performance and ovarian antioxidant capacity in aging laying hens. A total of 450 laying hens were assigned to five treatments. Dietary treatments included the following: a basal diet (diet without Se supplementation, CON) and basal diets supplemented with 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se from SEC, or 0.3 mg/kg Se from SEC and 0.3 mg/kg Se from SEY (SEC + SEY). Results showed that supplementation with SEC tended to increase the laying rate, increased the Haugh unit of eggs, and reduced the FCR. SEC promoted ovarian cell proliferation, inhibited apoptosis, and ameliorated the maintenance of follicles. SEC, SEY, or SEC + SEY increased ovarian T-AOC and decreased MDA levels. SEC increased the mRNA abundance of ovarian selenoproteins. SEC and SEC + SEY increased the mRNA abundance of Nrf2, HO-1, and NQO1, and decreased the mRNA abundance of Keap1. These results indicate that SEC could potentially to improve laying performance and egg quality via the enhancement of ovarian antioxidant capacity. SEC exerts an antioxidant function through the modulation of the Nrf2/Keap1 signaling pathway.

It is an important way for healthy Selenium (Se) supplement to transform exogenous Se into organic Se through crops. In the present study, Vigna unguiculata was selected as a test material and sprayed with biological nano selenium (SeNPs) and Na2SeO3, and its nutrient composition, antioxidant capacity, total Se and organic Se content were determined, respectively. Further, the response of ABC transporter family members in cowpea to different exogenous Se treatments was analyzed by transcriptome sequencing combined with different Se forms. The results show that the soluble protein content of cowpea increased after twice Se treatment. SeNPs treatment increased the content of cellulose in cowpea pods. Na2SeO3 treatment increased the content of vitamin C (Vc) in cowpea pods. Se treatments could significantly increase the activities of Peroxidase (POD), polyphenol oxidase (PPO) and catalase (CAT) in cowpea pods and effectively maintain the activity of Superoxide dismutase (SOD). SeNPs can reduce the content of malondialdehyde (MDA) in pods. After Se treatment, cowpea pods showed a dose-effect relationship on the absorption and accumulation of total Se, and Na2SeO3 treatment had a better effect on the increase of total Se content in cowpea pods. After treatment with SeNPs and Na2SeO3, the Se species detected in cowpea pods was mainly SeMet, followed by MeSeCys. Inorganic Se can only be detected in the high concentration treatment group. Analysis of transcriptome data of cowpea treated with Se showed that ABC transporters could play an active role in response to Se stress and Se absorption, among which ABCB, ABCC and ABCG subfamilies played a major role in Se absorption and transportation in cowpea. Further analysis by weighted gene co-expression network analysis (WGCNA) showed that the content of organic Se in cowpea treated with high concentration of SeNPs was significantly and positively correlated with the expression level of three transporters ABCC11, ABCC13 and ABCC10, which means that the ABCC subfamily may be more involved in the transmembrane transport of organic Se in cells.

Monascus red pigments (MRPs), which are a kind of natural colorant produced by Monascus spp., are widely used in the food and health supplements industry but are not very stable during processing and storage. Thus, MRPs were embedded into liposome membranes using a thin-film ultrasonic method to improve stability in this study. Monascus red pigments liposomes (MRPL) exhibited spherical unilamellar vesicles (UV) with particle size, polydispersity indexes (PDI), and zeta potential of 20–200 nm, 0.362 ± 0.023, and −42.37 ± 0.21 mV, respectively. pH, thermal, light, metal ion, storage, and in vitro simulated gastrointestinal digestion stability revealed that, compared with free MRPs, liposomes embedding significantly enhanced the stability of MRPs when exposed to adverse environmental conditions. Furthermore, anticancer assay suggested that MRPL exhibited a stronger inhibitory effect on MKN-28 cells by damaging the integrity of cells, with the IC50 value at 0.57 mg/mL. Overall, MRPLs possess stronger stability in external environment and in vitro simulated digestion with greater anticancer activity, indicating that MRPLs have the potential for promising application in the functional foods and pharmaceutical industries.

Selenium is an essential microelement required for human health. The biotransformation of selenium nanoparticles has attracted increasing attention in recent years. However, little of the literature has investigated the comprehensive evaluation of the strains for practical application and the effect on the functional properties in the existence of Se. The present study showed the selenite reduction strain Bacillus subtilis T5 (up to 200 mM), which could produce high yields of selenium polysaccharides and selenium nanoparticles in an economical and feasible manner. Biosynthesized selenium nanoparticles by B. subtilis T5 were characterized systematically using UV-vis spectroscopy, FTIR, Zeta Potential, DLS, and SEM techniques. The biosynthesized SeNPs exhibited high stability with small particle sizes. B. subtilis T5 also possessed a tolerance to acidic pH and bile salts, high aggregation, negative hemolytic, and superior antioxidant activity, which showed excellent probiotic potential and can be recommended as a potential candidate for the selenium biopharmaceuticals industry. Remarkably, B. subtilis T5 showed that the activity of α-amylase was enhanced with selenite treatment to 8.12 U/mL, 2.72-fold more than the control. The genus Bacillus was first reported to produce both selenium polysaccharides with extremely high Se-content (2.302 g/kg) and significantly enhance the activity to promote α-amylase with selenium treatment. Overall, B. subtilis T5 showed potential as a bio-factory for the biosynthesized SeNPs and organ selenium (selenium polysaccharide), providing an appealing perspective for the biopharmaceutical industry.

Selenium (Se) is a chemical element essential to human health because of its bioactive properties, including antioxidative, anticancer, and immunomodulating activities. Despite the high therapeutic potential of Se, its intrinsic properties of poor stability, a narrow therapeutic window, and low bioavailability and bioactivity have limited its clinical applications. Selenium nanoparticles (SeNPs) exhibit lower toxicity and higher bioactivity than other Se forms. Herein, we report a green method for the preparation of monodisperse SeNPs with starch microgel (SM) and epigallocatechin gallate (EGCG) through Se-O bonds and polysaccharide–polyphenol interactions (namely, SM-EGCG-SeNPs). SM-EGCG-SeNPs showed higher stability, bioactivities, and cytotoxicity than SeNPs and SM-SeNPs at the equivalent dose. SM-EGCG-SeNPs induced the apoptosis of cancer cells via the activation of several caspases and reactive oxygen species overproduction. This work proposes a facile method for the design and potentiation of structure-bioactive SeNPs via polysaccharide–polyphenol interactions.

Plant growth is affected by various abiotic stresses, including water, temperature, light, salt, and heavy metals. Selenium (Se) is not an essential nutrient for plants but plays important roles in alleviating the abiotic stresses suffered by plants. This article summarizes the Se uptake and metabolic processes in plants and the functions of Se in response to water, temperature, light, salt, and heavy metal stresses in plants. Se promotes the uptake of beneficial substances, maintains the stability of plasma membranes, and enhances the activity of various antioxidant enzymes, thus alleviating adverse effects in plants under abiotic stresses. Future research directions on the relationship between Se and abiotic stresses in plants are proposed. This article will further deepen our understanding of the relationship between Se and plants.

Pueraria lobata (wild.) Ohwi is a leguminous plant and one of the traditional Chinese herbal medicines. Its puerarin extract is widely used in the pharmaceutical industry. This study reported a chromosome-level genome assembly for P. lobata and its characteristics. The genome size was ~939.2 Mb, with a contig N50 of 29.51 Mbp. Approximately 97.82% of the assembled sequences were represented by 11 pseudochromosomes. We identified that the repetitive sequences accounted for 63.50% of the P. lobata genome. A total of 33,171 coding genes were predicted, of which 97.34% could predict the function. Compared with other species, P. lobata had 757 species-specific gene families, including 1874 genes. The genome evolution analysis revealed that P. lobata was most closely related to Glycine max and underwent two whole-genome duplication (WGD) events. One was in a gamma event shared by the core dicotyledons at around 65 million years ago, and another was in the common ancestor shared by legume species at around 25 million years ago. The collinearity analysis showed that 61.45% of the genes (54,579 gene pairs) in G. max and P. lobata had collinearity. In this study, six unique PlUGT43 homologous genes were retrieved from the genome of P. lobata, and no 2-hydroxyisoflavanone 8-C-glucoside was found in the metabolites. This also revealed that the puerarin synthesis was mainly from the glycation of daidzein. The combined transcriptome and metabolome analysis suggested that two bHLHs, six MYBs and four WRKYs were involved in the expression regulation of puerarin synthesis structural genes. The genetic information obtained in this study provided novel insights into the biological evolution of P. lobata and leguminous species, and it laid the foundation for further exploring the regulatory mechanism of puerarin synthesis.

Ginkgolide is a unique terpenoid natural compound in Ginkgo biloba, and it has an important medicinal value. Proper selenium has been reported to promote plant growth and development, and improve plant quality, stress resistance, and disease resistance. In order to study the effects of exogenous selenium (Se) on the physiological growth and the content of terpene triolactones (TTLs) in G. biloba seedlings, the seedlings in this work were treated with Na2SeO3. Then, the physiological indexes, the content of the TTLs, and the expression of the related genes were determined. The results showed that a low dose of Na2SeO3 was beneficial to plant photosynthesis as it promoted the growth of ginkgo seedlings and increased the root to shoot ratio. Foliar Se application significantly increased the content of soluble sugar and protein and promoted the content of TTLs in ginkgo leaves; indeed, it reached the maximum value of 7.95 mg/g in the ninth week, whereas the application of Se to the roots inhibited the synthesis of TTLs. Transcriptome analysis showed that foliar Se application promoted the expression levels of GbMECPs, GbMECT, GbHMGR, and GbMVD genes, whereas its application to the roots promoted the expression of GbDXS and GbDXR genes. The combined analysis results of metabolome and transcriptome showed that genes such as GbDXS, GbDXR, GbHMGR, GbMECPs, and GbCYP450 were significantly positively correlated with transcription factors (TFs) GbWRKY and GbAP2/ERF, and they were also positively correlated with the contents of terpene lactones (ginkgolide A, ginkgolide B, ginkgolide M, and bilobalide). Endogenous hormones (MeJA-ILE, ETH, and GA7) were also involved in this process. The results suggested that Na2SeO3 treatment affected the transcription factors related to the regulation of endogenous hormones in G. biloba, and further regulated the expression of genes related to the terpene synthesis structure, thus promoting the synthesis of ginkgo TTLs.

Cardamine violifolia, a species belonging to the Brassicaceae family, is a selenium hyperaccumulator and a nutritious leafy vegetable. Our previous study showed that C. violifolia leaves are rich in total phenolic acids, but the composition and corresponding genes remain unknown. In this study, we investigated the phenolic acid compounds and potential gene regulation network in the outer leaves (OL) and central leaves (CL) of C. violifolia using transcriptome and metabolome analyses. Results showed that the OL contained a higher total phenolic acid content than the CL. Metabolome analysis revealed a total of 115 phenolic acids, 62 of which (e.g., arbutin, rosmarinic acid, hydroxytyrosol acetate, and sinapic acid) were differentially accumulated between the CL and OL of C. violifolia. Transcriptome analysis showed that the differentially expressed genes were significantly enriched in the pathways of secondary metabolite biosynthesis and phenylpropanoid biosynthesis. Conjoint analysis of the transcriptome and metabolome indicated that seven genes (CYP84A1, CYP84A4, CADH9, SGT1, UGT72E1, OMT1, and CCR2) and eight phenolic acids (sinapic acid, sinapyl alcohol, 5-O-caffeoylshikimic acid, sinapoyl malate, coniferin, coniferyl alcohol, L-phenylalanine, and ferulic acid) constituted a possible regulatory network. This study revealed the phenolic acid compounds and possible regulatory network of C. violifolia leaves and deepened our understanding of its nutrient value.

Selenium is an essential trace element which plays an important role in human immune regulation and disease prevention. Plants absorb inorganic selenium (selenite or selenate) from the soil and convert it into various organic selenides (such as seleno amino acids, selenoproteins, and volatile selenides) via the sulfur metabolic pathway. These organic selenides are important sources of dietary selenium supplementation for humans. Organoselenides can promote plant growth, improve nutritional quality, and play an important regulatory function in plant ecosystems. The release of selenium-containing compounds into the soil by Se hyperaccumulators can promote the growth of Se accumulators but inhibit the growth and distribution of non-Se accumulators. Volatile selenides with specific odors have a deterrent effect on herbivores, reducing their feeding on plants. Soil microorganisms can effectively promote the uptake and transformation of selenium in plants, and organic selenides in plants can improve the tolerance of plants to pathogenic bacteria. Although selenium is not an essential trace element for plants, the right amount of selenium has important physiological and ecological benefits for them. This review summarizes recent research related to the functions of selenium in plant ecosystems to provide a deeper understanding of the significance of this element in plant physiology and ecosystems and to serve as a theoretical basis and technical support for the full exploitation and rational application of the ecological functions of selenium-accumulating plants.

Abstract Background Fraxinus hupehensis is an endangered tree species that is endemic to in China; the species has very high commercial value because of its intricate shape and potential to improve and protect the environment. Its seeds show very low germination rates in natural conditions. Preliminary experiments indicated that gibberellin (GA3) effectively stimulated the seed germination of F. hupehensis. However, little is known about the physiological and molecular mechanisms underlying the effect of GA3 on F. hupehensis seed germination. Results We compared dormant seeds (CK group) and germinated seeds after treatment with water (W group) and GA3 (G group) in terms of seed vigor and several other physiological indicators related to germination, hormone content, and transcriptomics. Results showed that GA3 treatment increases seed vigor, energy requirements, and trans-Zetain (ZT) and GA3 contents but decreases sugar and abscisic acid (ABA) contents. A total of 116,932 unigenes were obtained from F. hupehensis transcriptome. RNA-seq analysis identified 31,856, 33,188 and 2056 differentially expressed genes (DEGs) between the W and CK groups, the G and CK groups, and the G and W groups, respectively. Up-regulation of eight selected DEGs of the glycolytic pathway accelerated the oxidative decomposition of sugar to release energy for germination. Up-regulated genes involved in ZT (two genes) and GA3 (one gene) biosynthesis, ABA degradation pathway (one gene), and ABA signal transduction (two genes) may contribute to seed germination. Two down-regulated genes associated with GA3 signal transduction were also observed in the G group. GA3-regulated genes may alter hormone levels to facilitate germination. Candidate transcription factors played important roles in GA3-promoted F. hupehensis seed germination, and Quantitative Real-time PCR (qRT-PCR) analysis verified the expression patterns of these genes. Conclusion Exogenous GA3 increased the germination rate, vigor, and water absorption rate of F. hupehensis seeds. Our results provide novel insights into the transcriptional regulation mechanism of effect of exogenous GA3 on F. hupehensis seed germination. The transcriptome data generated in this study may be used for further molecular research on this unique species.

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 (Se) is an essential trace element for humans and animals, and it plays an important role in immune regulation and disease prevention. Tea is one of the top three beverages in the world, and it contains active ingredients such as polyphenols, theanine, flavonoids, and volatile substances, which have important health benefits. The tea tree has suitable Se aggregation ability, which can absorb inorganic Se and transform it into safe and effective organic Se through absorption by the human body, thereby improving human immunity and preventing the occurrence of many diseases. Recent studies have proven that 50~100.0 mg/L exogenous Se can promote photosynthesis and absorption of mineral elements in tea trees and increase their biomass. The content of total Se and organic selenides in tea leaves significantly increases and promotes the accumulation of polyphenols, theanine, flavonoids, and volatile secondary metabolites, thereby improving the nutritional quality of tea leaves. This paper summarizes previous research on the effects of exogenous Se treatment on the growth and quality of tea trees to provide a theoretical basis and technical support for the germplasm selection and exploitation of Se-rich tea.

Pulsed electric fields (PEF) and ultrasonic-assisted extraction (UE) were applied to improve the extraction performance of selenium-enriched tea polysaccharides (Se−TPSs) in mild conditions. Two combined extraction processes were investigated: (1) PEF strength at 10 kV/cm followed by conventional extraction (CE) at 50 °C for 60 min and (2) PEF+UE (PEF strength at 10 kV/cm followed by UE at 400 W for 60 min). The optimal extraction yields, and energy consumption rates were obtained at 36.86% and 41.53% and 78.78 kJ/mg and 133.91 kJ/mg, respectively. The Se−TPSs were analyzed and characterized by GPC, UV, and FT-IR, which evidenced the structural stability of the Se−TPSs during the extraction processes. It was found that PEF and UE could reduce the particle size diameter of the Se−TPS extract, as well as the proportion of uronic acid. Moreover, PEF could increase the selenium content in the Se−TPS extract by 160.14% due to a lower extraction temperature compared to conventional extraction. The antioxidant activities of the Se−TPSs in vitro were investigated using OH, O2−, and ABTS+ scavenging experiments, as well as a total antioxidant ability evaluation. It was found that the antioxidant activity of the Se−TPSs obtained using PEF2+CE2 was relatively high due to the potential synergistic effect between the selenium and polysaccharides. Based on these results, we speculate that PEF2+CE2 was the best extraction process for the Se−TPSs. Furthermore, this research indicates the application of selenium-enriched tea for functional food production.

As a functional beverage, selenium (Se)-enriched green tea (Se-GT) has gained increasing popularity for its superior properties in promoting health. In this study, we compared the brewing characteristics, in vitro digestion profiles, and protective effects on neurotoxicity induced through the amyloid-beta (Aβ) peptide of two typical Se-GTs (Enshi Yulu (ESYL) and Ziyang Maojian (ZYMJ), representing the typical low-Se green tea and high-Se green tea, respectively). ESYL and ZYMJ showed similar chemical component leaching properties with the different brewing methods, and the optimized brewing conditions were 5 min, 90 °C, 50 mL/g, and first brewing. The antioxidant activities of the tea infusions had the strongest positive correlation with the tea polyphenols among all of the leaching substances. The tea infusions of ESYL and ZYMJ showed similar digestive behaviors, and the tea polyphenols in the tea infusions were almost totally degraded or transferred after 150 min of dynamic digestion. Studies conducted in a cell model of Alzheimer’s disease (AD) showed that the extract from the high-Se green tea was more effective for neuroprotection compared with the low-Se green tea. Overall, our results revealed the best brewing conditions and digestion behaviors of Se-GT and the great potential of Se-GT or Se-enriched green extract (Se-GTE) to be used as promising AD-preventive beverages or food ingredients.

The inorganic selenium is absorbed and utilized inefficiently, and the range between toxicity and demand is narrow, so the application is strictly limited. Selenium nanoparticles have higher bioactivity and biosafety properties, including increased antioxidant and anticancer properties. Thus, producing and applying eco-friendly, non-toxic selenium nanoparticles in feed additives is crucial. Bacillus paralicheniformis Y4 was investigated for its potential ability to produce selenium nanoparticles and the activity of carboxymethyl cellulases. The selenium nanoparticles were characterized using zeta potential analyses, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Additionally, evaluations of the anti-α-glucosidase activity and the antioxidant activity of the selenium nanoparticles and the ethyl acetate extracts of Y4 were conducted. B. paralicheniformis Y4 exhibited high selenite tolerance of 400 mM and the selenium nanoparticles had an average particle size of 80 nm with a zeta potential value of −35.8 mV at a pH of 7.0, suggesting that the particles are relatively stable against aggregation. After 72 h of incubation with 5 mM selenite, B. paralicheniformis Y4 was able to reduce it by 76.4%, yielding red spherical bio-derived selenium nanoparticles and increasing the carboxymethyl cellulase activity by 1.49 times to 8.96 U/mL. For the first time, this study reports that the carboxymethyl cellulase activity of Bacillus paralicheniforis was greatly enhanced by selenite. The results also indicated that B. paralicheniformis Y4 could be capable of ecologically removing selenite from contaminated sites and has great potential for producing selenium nanoparticles as feed additives to enhance the added value of agricultural products.

Camellia japonica petals are colorful, rich in anthocyanins, and possess important ornamental, edible, and medicinal value. However, the regulatory mechanism of anthocyanin accumulation in C. japonica is still unclear. In this study, an integrative analysis of the metabolome and transcriptome was conducted in five C. japonica cultivars with different petal colors. Overall, a total of 187 flavonoids were identified (including 25 anthocyanins), and 11 anthocyanins were markedly differentially accumulated among these petals, contributing to the different petal colors in C. japonica. Moreover, cyanidin-3-O-(6″-O-malonyl) glucoside was confirmed as the main contributor to the red petal phenotype, while cyanidin-3-O-rutinoside, peonidin-3-O-glucoside, cyanidin-3-O-glucoside, and pelargonidin-3-O-glucoside were responsible for the deep coloration of the C. japonica petals. Furthermore, a total of 12,531 differentially expressed genes (DEGs) and overlapping DEGs (634 DEGs) were identified by RNA sequencing, and the correlation between the expression level of the DEGs and the anthocyanin content was explored. The candidate genes regulating anthocyanin accumulation in the C. japonica petals were identified and included 37 structural genes (especially CjANS and Cj4CL), 18 keys differentially expressed transcription factors (such as GATA, MYB, bHLH, WRKY, and NAC), and 16 other regulators (mainly including transporter proteins, zinc-finger proteins, and others). Our results provide new insights for elucidating the function of anthocyanins in C. japonica petal color expression.

As a common mutation trait in plants, leaf colour mutation is related to the degree of chlorophyll and anthocyanin changes and the destruction of chloroplast structure. This study summarizes the latest research progress in leaf colour mutation mechanism, including the metabolic basis of plant leaf colour mutation, leaf colour mutation caused by gene mutation in the chlorophyll metabolism pathway, leaf colour mutation caused by blocked chloroplast development, leaf colour mutation controlled by key transcription factors and non-coding RNAs, leaf colour mutation caused by environmental factors, and leaf colour mutation due to the involvement of the mevalonate pathway. These results will lay a theoretical foundation for leaf colour development, leaf colour improvement, and molecular breeding for leaf colour among tree species.

Ginkgo biloba has edible, medicinal, and ornamental value. However, the long juvenile phase prevents the development of the G. biloba industry, and there are few reports on the identification and functional analysis of genes regulating the flowering time of G. biloba. EMBRYONIC FLOWER 2 (EMF), an important protein in flower development, functions to promote vegetative growth and repress flowering. In this study, a novel EMF gene (GbEMF2) was cloned and characterized from G. biloba. GbEMF2 contains a 2,193 bp open reading frame (ORF) encoding 730 amino acids. GbEMF2 harbors conserved VEFS-Box domain by the plant EMF protein. The phylogenic analysis showed that GbEMF2 originated from a polycomb-group (Pc-G) protein ancestor and was a member of the EMF2 protein. The quantitative real-time PCR (qRT-PCR) analysis revealed that GbEMF2 was expressed in all detected organs, and it showed a significantly higher level in ovulating strobilus and microstrobilus than in other organs. Compared with emf2 mutant plants, overexpression of GbEMF2 driven by the CaMV 35S promoter in emf2 mutant Arabidopsis plants delayed flowering but earlier than wild-type (WT) plants. This result indicated that GbEMF2 repressed flowering in G. biloba. Moreover, the RNA-seq analysis of GbEMF2 transgenic Arabidopsis plants (GbEMF2-OE/emf2), WT plants, and emf2 mutants screened out 227 differentially expressed genes (DEGs). Among these DEGs, FLC, MAF5, and MAF5-1 genes were related to flower organ development and regulated by GbEMF2. In addition, some genes participating in sugar metabolism, such as Alpha-amylase 1 (AMY1), BAM1, and Sucrose synthase 3 (SUS3) genes, were also controlled by GbEMF2. Overall, our results suggested that GbEMF2 negatively regulates flowering development in G. biloba. This finding provided a foundation and target gene for shortening the Ginkgo juvenile period by genetic engineering technology.

Oxidative stress is closely associated with aging and age-related neurodegenerative diseases and plays a vital function in their initiation and progression. Selenium-enriched peptides from Cardamine violifolia (CSP) had excellent antioxidant function in vitro, however, whether it has an effect on aging is still unknown. In this study, the results revealed that CSP supplementation could ameliorate d-galactose (d-gal) induced metabolism disorder, memory dysfunction, and neuron damage in the hippocampus. Moreover, CSP alleviated ROS and MDA levels by increasing the activities of SOD, GSH-Px, CAT, and TAOC, and activate the Nrf2/HO-1/NQO1 pathway, which probably represents an anti-aging mechanism of CSP. Furthermore, CSP reduced the neuro-inflammation by inhibiting the NF-κB pathway in d-gal induced aging rats and suppressed RAGE and P-JNK signaling pathway. Altogether, the study firstly demonstrated the favorable effects of CSP against brain aging, which can be further developed as a promising strategy to prevent or treat age-related neurodegenerative diseases.