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Saponins are a class of glycosides whose aglycones can be either triterpenes or helical spirostanes. It is commonly recognized that these active ingredients are widely found in various kinds of advanced plants. Rare saponins, a special type of the saponins class, are able to enhance bidirectional immune regulation and memory, and have anti-lipid oxidation, anticancer, and antifatigue capabilities, but they are infrequent in nature. Moreover, the in vivo absorption rate of saponins is exceedingly low, which restricts their functions. Under such circumstances, the biotransformation of these ingredients from normal saponins—which are not be easily adsorbed by human bodies—is preferred nowadays. This process has multiple advantages, including strong specificity, mild conditions, and fewer byproducts. In this paper, the biotransformation of natural saponins—such as ginsenoside, gypenoside, glycyrrhizin, saikosaponin, dioscin, timosaponin, astragaloside and ardipusilloside—through microorganisms (Aspergillus sp., lactic acid bacteria, bacilli, and intestinal microbes) will be reviewed and prospected.

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.

Basic helix–loop–helix (bHLH) proteins, one of the most important and largest transcription factor family in plants, play important roles in regulating growth and development, stress response. In recent years, many bHLH family genes have been identified and characterized in woody plants. However, a systematic analysis of the bHLH gene family has not been reported in Ginkgo biloba , the oldest relic plant species. In this study, we identifed a total of 85 GbbHLH genes from the genomic and transcriptomic databases of G. biloba , which were classified into 17 subfamilies based on the phylogenetic analysis. Gene structures analysis indicated that the number of exon–intron range in GbbHLHs from 0 to 12. The MEME analysis showed that two conserved motifs, motif 1 and motif 2, distributed in most GbbHLH protein. Subcellular localization analysis exhibited that most GbbHLHs located in nucleus and a few GbbHLHs were distributed in chloroplast, plasma membrane and peroxisome. Promoter cis-element analysis revealed that most of the GbbHLH genes contained abundant cis-elements that involved in plant growth and development, secondary metabolism biosynthesis, various abiotic stresses response. In addition, correlation analysis between gene expression and flavonoid content screened seven candidate GbbHLH genes involved in flavonoid biosynthesis, providing the targeted gene encoding transcript factor for increase the flavonoid production through genetic engineering in G. biloba .

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.

The air quality in the Beijing–Tianjin–Hebei region of China has markedly improved in recent decades. Characterizing current PM2.5 transmission between cities in light of the continuous reduction in emissions from various sources is of great significance for the formulation of future regional joint prevention and control strategies. To address these issues, a WRF-CAMx modeling project was implemented to explore the pollution characteristics from the perspectives of transport flux, regional source apportionment, and the comprehensive impact of multiple pollutants from 2013 to 2020. It was found that the net PM2.5 transport flux among cities declined considerably during the study period and was positively affected by the continuous reduction in emission sources. The variations in local emissions and transport contributions in various cities from 2013 to 2020 revealed differences in emission control policies and efforts. It is worth noting that under polluted weather conditions, obvious interannual differences in PM2.5 transport fluxes in the BTH region were observed, emphasizing the need for more scientifically based regional collaborative control strategies. The change in the predominant precursor from SO2 to NOx has posed new challenges for emission reduction. NOx emission reductions will significantly decrease PM2.5 concentrations, while SO2 and NH3 reductions show limited effects. The reduction in NOx emissions might have a fluctuating impact on the generation of SOAs, possibly due to changes in atmospheric oxidation. However, the deep treatment of NOx has a positive effect on the synergistic improvement of multiple air pollutants. This emphasizes the need to enhance the reduction in NOx emissions in the future. The results of this study can serve as a reference for the development of effective PM2.5 precursor control strategies and regional differentiation optimization improvement policies in the BTH region.

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.

The exceptional physicochemical properties of selenium nanoparticles (SeNPs) have led to their widespread development. The function of SeNPs is significantly influenced by their shape and particle size, which are in turn determined by the applied synthesis methods. This work presents a critical and comparative analysis of physical, chemical, and biosynthetic methods. The key point is to elaborate on how different methods precisely regulate the particle size, morphology, and stability that are crucial to their functional efficacy. This work emphasizes the importance of creating standardized protocols for characterizing SeNPs in order to make meaningful comparisons between the effectiveness of various studies. We further elucidate the underlying mechanisms of SeNPs’ anti-tumor, antioxidant, and antibacterial activities. A key novelty of this work lies in its systematic construction of a bridge between the synthesis, properties, functions, applications, and translational potential and its provision of a critical assessment. Finally, the review identifies and summarizes the principal challenges hindering clinical and commercial translation, including the imperative for standardized toxicological evaluation, scalable synthesis, and regulatory alignment.

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.

The seasonal variation of PM 2.5 carbonaceous aerosol was investigated in Beijing and Tangshan cities of China. The characteristics of carbonaceous aerosol (e.g., organic carbon, OC and elemental carbon, EC) under different weather conditions and their source apportionment were also examined. The annual average PM 2.5 concentration in the study area reached 95.6–197.3 μg/m 3 , showing seasonal and spatial variation. The carbonaceous materials accounted for 17.3–21.2 % of the PM 2.5 , and they had a much higher content under haze weather condition. It was found that the PM 2.5 contained more OC than EC. Principal component analysis (PCA) results indicated that the carbonaceous components came from mixed emission sources of coal combustion, vehicle exhaust, and biomass burning. In Beijing, the vehicle emission made a contribution of 63.0 % to the carbonaceous components of PM 2.5 in summer, which is higher than that in Tangshan. While in Tangshan, the coal combustion made a contribution of 30.3 %, which is much higher than that in Beijing.

Microorganisms can produce many antibiotics against bacteria and fungi, which have been used as a potential choice of new antibiotics. In this paper, we studied the characteristics of antibacterial substances by Bacillus cereus BC1. The results showed that the acid-precipitated substance played the main role in antibacterial activity, and further characterization indicated that the antibacterial substance might be a lipopeptide substance. Then the antibacterial spectrum suggested that the antibacterial substance had an inhibitory effect on Gram-positive bacteria and fungi, while selenium-riched antibacterial substance of Bacillus cereus BC1 could significantly enhance the inhibition. Then the morphological effects of the antibacterial substance to indicator bacteria were determined. The effects of different treatment methods on the stability of antibacterial substances were studied and the results showed that the antibacterial substance was stable to heat, ultrasonic, and ultraviolet treatment, and their antibacterial activity would not be greatly affected. However, they were sensitive to pepsin. The optimum pH range of antibacterial activity was 3–5. This study may contribute to reusing the fermentation supernatant often discarded in the previous fermentation process. At the same time, the lipopeptide antibacterial substance extracted from the fermentation broth of selenium-enriched Bacillus cereus BC1 can be used in the development of antibiotics and biopesticides, and open up a new way for the control of plant diseases.