Genistein mitigates diet-induced obesity and metabolic dysfunctions in gonadectomized mice with some sex-differential effects.

Background: Obesity is associated with insulin resistance (IR) and metabolic dysfunction-associated steatotic liver disease (MASLD). Genistein, an isoflavone, is a promising natural compound for preventing and treating obesity and metabolic dysfunctions. We aimed to investigate the sex-specific protective effects of genistein on obesity, IR, and MASLD in a murine model of sex hormone deprivation with diet-induced obesity (DIO), mimicking postmenopausal women or aging men with metabolic syndrome. Methods: Gonadectomized and sham-operated C57BL/6NJcl mice were fed a high-fat high-sucrose diet for 4 weeks to induce obesity (7 mice per group). In gonadectomized mice, genistein (16 mg/kg/day) or vehicle (7.5% dimethyl sulfoxide) was orally administered for 45 days. We assessed glucose homeostasis parameters, hepatic histopathology, and hepatic gene expression to investigate the effects of gonadectomy and genistein treatment. Results: Gonadectomy exacerbated adiposity in both sexes. Ovariectomy diminished the protective effects of female gonadal hormones on the homeostatic model assessment for insulin resistance (HOMA-IR), serum alanine transaminase levels, hepatic steatosis score, and the expression of hepatic genes associated with MASLD progression and IR, such as Fasn, Srebf1, Saa1, Cd36, Col1a1, Pck1, and Ppargc1a. Genistein treatment in gonadectomized mice significantly reduced body weight gain and the hepatic steatosis score in both sexes. However, genistein treatment significantly attenuated HOMA-IR and the expression of the hepatic genes only in female mice. Conclusion: Genistein treatment mitigates DIO-related MASLD in both male and female gonadectomized mice. Regarding hepatic gene expression associated with MASLD and IR, the beneficial effect of genistein was significantly evident only in female mice. This study suggests a potential alternative application of genistein in individuals with obesity and sex hormone deprivation, yet pending clinical trials.

Anxiolytic and Antianhedonic-like Effects of Psidium guajava Leaf in Alcohol-Withdrawn Mice.

Objectives: Alcohol withdrawal syndrome manifests through a range of symptoms, including anxiety and anhedonia, significantly affecting the quality of life of those affected. This study investigates the potential therapeutic effects of the methanolic extract of Psidium guajava leaves (MPG) on anxiety and anhedonia in Swiss albino female mice undergoing alcohol withdrawal. Methods: Four groups of mice underwent alcohol withdrawal, with one group undergoing saline withdrawal as a control. On the test day, behavioral assessments were conducted to evaluate anxiety and anhedonia. Groups I and II received sodium carboxymethylcellulose, Group III received diazepam, and Groups IV and V received varying oral doses of MPG. Results: The results indicate significant anti-anhedonic and anxiolytic effects of MPG. These effects were observed through changes in parameters measured in the Open Field test, Elevated Plus Maze test, Marble Burying test, and Sucrose Preference test. Mice treated with MPG displayed reduced anxiety-like behaviors and increased sucrose preference compared to untreated mice undergoing alcohol withdrawal. Conclusion: These findings suggest that Psidium guajava leaf extract may have therapeutic potential in alleviating anxiety and anhedonia associated with alcohol withdrawal. The observed effects indicate that MPG could serve as a promising adjunct therapy for managing alcohol withdrawal symptoms, thereby enhancing the overall well-being of individuals undergoing alcohol cessation.

Mitogen-Activated Protein Kinase Mediated Regulation of Plant Specialized Metabolism.

Post-transcriptional and post-translational modification of transcription factors (TFs) and pathway enzymes significantly affect the stress-stimulated biosynthesis of specialized metabolites (SM). Protein phosphorylation is one of the conserved and ancient mechanisms that critically influences many biological processes including specialized metabolism. The phosphorylation of TFs and enzymes by protein kinases (PKs), especially the Mitogen-Activated Protein Kinases (MAPKs), is well-studied in plants. While the roles of MAPKs in plant growth and development, phytohormone signaling, and immunity are well elucidated, significant recent advances have also been made in understanding the involvement of MAPKs in specialized metabolism. However, a comprehensive review highlighting the significant progress in the past several years is notably missing. This review focuses on MAPK-mediated regulation of several important SM, including phenylpropanoids (flavonoids and lignin), terpenoids (artemisinin and other terpenoids), alkaloids (terpenoid indole alkaloids and nicotine), and other nitrogen- and sulfur-containing SM (camalexin and indole glucosinolates). In addition to MAPKs, other PKs also regulate SM biosynthesis. For comparison, we briefly discuss the regulation by other PKs, such as sucrose non-fermenting-1 (SNF)-related protein kinases (SnRKs) and calcium-dependent protein kinases (CPKs). Furthermore, we provide future perspectives in this active area of research.

Continental-scale insights into the sugarbeet diffusion juice microbiomes.

Bacterial contamination of raw diffusion juice poses unique challenges during the sugar extraction process. This study profiled bacterial communities by using full-length 16S rRNA amplicon sequencing and quantified the carbohydrate concentrations in raw diffusion juice samples received from sugar factory regions across the USA and Canada. Juice samples were collected at four time points during the 2021 and 2022 processing campaigns. Firmicutes was the dominant phylum from the raw diffusion juice samples collected during both campaigns and comprised 85.5% of total bacterial abundance. Lactic acid bacteria such as Leuconostoc and Lactobacillus were among the core genera which also dominated the bacterial community in raw diffusion juice. Positive correlations in the abundance of functionally and taxonomically related bacterial communities were identified. During the 2021 campaign, 44 bacterial genera were differentially abundant in raw diffusion juice extracted from sugarbeet roots in Periods 1 to 4. This number declined sixfold during the 2022 campaign to three genera. The concentration of raffinose in raw diffusion juice positively correlated to the relative abundance of Leuconostoc. Furthermore, an in vitro assay was performed to assess the growth dynamics of Leuconostoc mesenteroides in sucrose or raffinose-rich medium and observed the rapid consumption of both carbohydrates by this bacterium. This finding is important for deciphering microbial growth dynamics in raw diffusion juice that can be useful in minimizing sugar loss during the factory processing.IMPORTANCEFindings additionally provide baseline information that can be used to develop mitigation strategies that reduce losses due to microbial contamination of sucrose processing streams.

Sweetpotato sucrose transporter IbSUT1 alters storage roots formation by regulating sucrose transport and lignin biosynthesis.

The formation and development of storage roots is the most important physiological process in sweetpotato production. Sucrose transporters (SUTs) regulate sucrose transport from source to sink organs and play important roles in growth and development of plants. However, whether SUTs involved in sweetpotato storage roots formation is so far unknown. In this study, we show that IbSUT1, a SUT, is localized to the plasma membrane. Overexpression of IbSUT1 in sweetpotato promotes the sucrose efflux rate from leaves, leading to increased sucrose levels in roots, thus induces lignin deposition in the stele, which inhibits the storage roots formation and compromises the yield. Heterologous expression of IbSUT1 in Arabidopsis significantly increases the sucrose accumulation and promotes lignification in the inflorescence stems. RNA-seq and biochemical analysis further demonstrated that IbMYB1 negatively regulates the expression of IbSUT1. Overexpression of IbMYB1 in Arabidopsis reduces the sucrose accumulation and lignification degree in the inflorescence stems. Moreover, co-overexpression of IbMYB1 and IbSUT1 restores the phenotype of lignin over-deposition in Arabidopsis. Collectively, our results reveal that IbSUT1 regulates source-sink sucrose transport and participates in the formation of sweetpotato storage roots and highlight the potential application of IbSUT1 in improving sweetpotato yield in the future.

Quantitative proteomic analysis reveals hub proteins for high temperature-induced male sterility in bread wheat (Triticum aestivum L.).

High-temperature (HT) stress can induce male sterility in wheat; however, the underlying mechanisms remain poorly understood. This study examined proteomic alterations across three developmental stages between normal and HT-induced male-sterile (HT-ms) anthers in wheat. Utilizing tandem mass tags-based proteomics, we identified 2532 differentially abundant proteins (DAPs): 27 in the tetrad stage, 157 in the binuclear stage, and 2348 in the trinuclear stage. Analyses through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways indicated significant enrichment of these DAPs in seven pathways, namely phenylpropanoid biosynthesis, flavonoid biosynthesis, sphingolipid metabolism, MAPK signaling pathway, starch and sucrose metabolism, response to heat, and response to reactive oxygen species (ROS). Our results indicated the downregulation of DAPs associated with phenylpropanoid biosynthesis and starch and sucrose metabolism, which aligns with anther indehiscence and the lack of starch in HT-ms anthers. By contrast, DAPs in the ROS pathway were upregulated, which aligns with excessive ROS accumulation in HT-ms anthers. Additionally, we conducted protein-protein interaction analysis for the DAPs of these pathways, identifying 15 hub DAPs. The abundance of these hub proteins was confirmed through qRT-PCR, assessing mRNA expression levels of the corresponding transcripts. Collectively, these results offer insights into the molecular mechanisms underlying HT-induced male sterility in wheat at the proteomic level, providing a valuable resource for further research in plant sexual reproduction.

Regulation of maize root growth by local phosphorus availability, sucrose metabolism, and partitioning.

BACKGROUND AND AIMS: Understanding how maize roots proliferate in phosphorus (P)-rich soil patches is critical for improving nutrient acquisition and crop productivity. This study explores the mechanisms of root adaptation to heterogeneous P availability, focusing on sucrose metabolism and the role of local P signals. METHODS: A split-root system with chambers of differing Pi concentrations (0 and 500 µM) was used to examine maize root responses. Various physiological and biochemical parameters, including root growth, sucrose partitioning, enzyme activities, and gene expression, were measured to elucidate the underlying mechanisms. KEY RESULTS: Root proliferation, particularly of second-order lateral roots, was markedly enhanced in P-rich patches. Sucrose was preferentially allocated to the Pi-supplied side, as confirmed by Fourier-transform infrared (FTIR) microscopy. Sucrose content in these roots decreased, indicating active metabolism. Higher activities of cell-wall invertase and sucrose synthase were observed in the Pi-supplied roots, supporting enhanced carbohydrate utilization. CONCLUSIONS: Local P availability triggers significant adjustments in sucrose metabolism and allocation, enhancing the sink capacity of maize roots in P-rich patches. These changes facilitate efficient lateral root proliferation and Pi utilization, highlighting the critical role of local P signals in nutrient acquisition strategies. This research provides deeper insights into the adaptive responses of maize to heterogeneous P environments, offering potential strategies for improving crop nutrient efficiency.

Intermittent access to sugary drinks associated with fasting induces overeating and depressive-like behavior in female C57BL/6J mice.

Binge eating disorder is the most prevalent eating disorder, affecting both sexes but more commonly found in women. Given the frequent co-occurrence of psychiatric disorders, this study aimed to establish a standardized experimental intermittent protocol to investigate overeating associated with depression. A 10-day protocol induced uncontrolled eating behavior in C57BL/6J female mice. The first experiment included the following groups: naive group (chow ad libitum), control group (chow and sucrose solution ad libitum), and fasting groups (16 and 20 h) exposed to an intermittent sucrose solution (10 %) and chow regimen. Subsequently, the feeding test, open field test, elevated plus maze test, tail suspension test, and light/dark conflict test were conducted. Furthermore, monoamine oxidase (MAO) A and B activities in brain structures and plasma corticosterone levels were assessed. Food overconsumption and depressive-like behavior were observed in both sucrose fasting groups, while risk-taking behaviors were specifically observed in the 20-hour fasting sucrose group. While both fasting sucrose groups caused reduced hippocampal MAO-A activity, only the F20 sucrose group inhibited MAO-B in the cortex and hypothalamus. Moreover, both fasting sucrose groups exhibited elevated corticosterone levels. In a separate design (Experiment 2), groups with 16 and 20 h of fasting alone (without sucrose) did not show the same behavioral results as the intermittent fasting sucrose groups, thus avoiding fasting bias. Based on these results, the 20-hour sucrose fasting group was chosen as the ideal protocol for mimicking overeating behavior associated with depression to investigate future therapeutic approaches for this comorbidity.

Methodology Approach for Microplastics Isolation from Samples Containing Sucrose.

The growing production and use of plastics significantly contribute to microplastics (MPs) contamination in the environment. Humans are exposed to MPs primarily through the gastrointestinal route, as these particles are present in beverages and food, e.g., sugar. Effective isolation and identification of MPs from food is essential for their elimination. This study aimed to evaluate factors influencing the isolation of MPs from sucrose solutions to determine optimal conditions for the process. Polyethylene particles were used to test separation methods involving chemical digestion with acids and filtration through membrane filters made of nylon, mixed cellulose ester, and cellulose acetate with pore sizes of 0.8 and 10 µm. The effects of temperature and acid type and its concentration on plastic particles were examined using scanning electron microscopy and µ-Raman spectroscopy. The results indicate that increased temperature reduces solution viscosity and sucrose adherence to MPs' particles, while higher acid concentrations accelerate sucrose hydrolysis. The optimal conditions for MPs' isolation were found to be 5% HCl at 70 °C for 5 min, followed by filtration using an efficient membrane system. These conditions ensure a high recovery and fast filtration without altering MPs' surface properties, providing a reliable basis for further analysis of MPs in food.

An Exploratory Study of the Enzymatic Hydroxycinnamoylation of Sucrose and Its Derivatives.

Phenylpropanoid sucrose esters are a large and important group of natural substances with significant therapeutic potential. This work describes a pilot study of the enzymatic hydroxycinnamoylation of sucrose and its derivatives which was carried out with the aim of obtaining precursors of natural phenylpropanoid sucrose esters, e.g., vanicoside B. In addition to sucrose, some chemically prepared sucrose acetonides and substituted 3'-O-cinnamates were subjected to enzymatic transesterification with vinyl esters of coumaric, ferulic and 3,4,5-trimethoxycinnamic acid. Commercial enzyme preparations of Lipozyme TL IM lipase and Pentopan 500 BG exhibiting feruloyl esterase activity were tested as biocatalysts in these reactions. The substrate specificity of the used biocatalysts for the donor and acceptor as well as the regioselectivity of the reactions were evaluated and discussed. Surprisingly, Lipozyme TL IM catalyzed the cinnamoylation of sucrose derivatives more to the 1'-OH and 4'-OH positions than to the 6'-OH when the 3'-OH was free and the 6-OH was blocked by isopropylidene. In this case, Pentopan reacted comparably to 1'-OH and 6'-OH positions. If sucrose 3'-O-coumarate was used as an acceptor, in the case of feruloylation with Lipozyme in CH3CN, 6-O-ferulate was the main product (63%). Pentopan feruloylated sucrose 3'-O-coumarate comparably well at the 6-OH and 6'-OH positions (77%). When a proton-donor solvent was used, migration of the 3'-O-cinnamoyl group from fructose to the 2-OH position of glucose was observed. The enzyme hydroxycinnamoylations studied can shorten the targeted syntheses of various phenylpropanoid sucrose esters.

Advancements in the Heterologous Expression of Sucrose Phosphorylase and Its Molecular Modification for the Synthesis of Glycosylated Products.

Sucrose phosphorylase (SPase), a member of the glycoside hydrolase GH13 family, possesses the ability to catalyze the hydrolysis of sucrose to generate α-glucose-1-phosphate and can also glycosylate diverse substrates, showcasing a wide substrate specificity. This enzyme has found extensive utility in the fields of food, medicine, and cosmetics, and has garnered significant attention as a focal point of research in transglycosylation enzymes. Nevertheless, SPase encounters numerous obstacles in industrial settings, including low enzyme yield, inadequate thermal stability, mixed regioselectivity, and limited transglycosylation activity. In-depth exploration of efficient expression strategies and molecular modifications based on the crystal structure and functional information of SPase is now a critical research priority. This paper systematically reviews the source microorganisms, crystal structure, and catalytic mechanism of SPase, summarizes diverse heterologous expression systems based on expression hosts and vectors, and examines the application and molecular modification progress of SPase in synthesizing typical glycosylated products. Additionally, it anticipates the broad application prospects of SPase in industrial production and related research fields, laying the groundwork for its engineering modification and industrial application.

Paraventricular oxytocin neurons impact energy intake and expenditure: projections to the bed nucleus of the stria terminalis reduce sucrose consumption.

Background: The part played by oxytocin and oxytocin neurons in the regulation of food intake is controversial. There is much pharmacological data to support a role for oxytocin notably in regulating sugar consumption, however, several recent experiments have questioned the importance of oxytocin neurons themselves. Methods: Here we use a combination of histological and chemogenetic techniques to investigate the selective activation or inhibition of oxytocin neurons in the hypothalamic paraventricular nucleus (OxtPVH). We then identify a pathway from OxtPVH neurons to the bed nucleus of the stria terminalis using the cell-selective expression of channel rhodopsin. Results: OxtPVH neurons increase their expression of cFos after both physiological (fast-induced re-feeding or oral lipid) and pharmacological (systemic administration of cholecystokinin or lithium chloride) anorectic signals. Chemogenetic activation of OxtPVH neurons is sufficient to decrease free-feeding in Oxt Cre:hM3Dq mice, while inhibition in Oxt Cre:hM4Di mice attenuates the response to administration of cholecystokinin. Activation of OxtPVH neurons also increases energy expenditure and core-body temperature, without a significant effect on locomotor activity. Finally, the selective, optogenetic stimulation of a pathway from OxtPVH neurons to the bed nucleus of the stria terminalis reduces the consumption of sucrose. Conclusion: Our results support a role for oxytocin neurons in the regulation of whole-body metabolism, including a modulatory action on food intake and energy expenditure. Furthermore, we demonstrate that the pathway from OxtPVH neurons to the bed nucleus of the stria terminalis can regulate sugar consumption.

Decreased consumption of natural rewards in rhesus monkeys with prolonged methamphetamine abstinence.

Rationale: Relapse to drug use is a major clinical challenge in the treatment of addictive disorders, including psychostimulant use and may be exacerbated by reduced sensitivity to natural, non-drug reward. Given the relatively limited set of outcomes, and short withdrawal time in rodent studies, we conducted a more detailed assessment of the response to natural rewards in methamphetamine (METH) naive versus exposed monkeys during long-term abstinence. Methods: This study introduced an improved sucrose preference test (iSPT) to assess natural reward seeking and consumption in monkeys with long-term abstinence after methamphetamine (METH) use. The test was administered to sixteen naive monkeys and five METH exposed monkeys that had been abstinent for at least 3 months. Results: METH exposed monkeys showed a lower sucrose preference score in both the iSPT (z = -2.10, p = 0.036) and the sucrose preference test (z = -2.61, p = 0.009). The sucrose preference score was significantly correlated with the latency of the establishment of stable sucrose-preference (r = -0.76, df = 46, p < 0.001) but not with the other variables. Furthermore, water-sucrose switch latency and switch times were significantly negatively correlated (r = -0.50, df = 20, p = 0.02). Conclusion: These results show reductions in natural reward consumption during long-term methamphetamine abstinence.

Soluble sugar, organic acid and phenolic composition and flavor evaluation of plum fruits.

Plums (Prunus salicina and Prunus domestica) are prevalent in southwestern China, and have attracted interest owing to their delectable taste and exceptional nutritional properties. Therefore, this study aimed to investigate the nutritional and flavor properties of plum to improve its nutritional utilization. Specifically, we determined the soluble sugars, organic acids, and phenolic components in 86 accessions using high-performance liquid chromatography. Notably, glucose, fructose, malic, and quinic acids were the predominant sweetness and acidity in plums, with sucrose contributing more to the sweetness of the flesh than the peel. Moreover, The peel contains 5.5 fold more phenolics than flesh, epicatechin, gallic acid, and proanthocyanidins C1 and B2 were the primary sources of astringency. Correlation and principal component analyses showed eight core factors for plum flavor rating, and a specific rating criterion was established. Conclusively, these findings provide information on the integrated flavor evaluation criteria and for enhancing optimal breeding of plums.

High-fat and High-sucrose Diet-induced Hypothalamic Inflammation Shows Sex Specific Features in Mice.

Hypothalamic inflammation underlies diet-induced obesity and diabetes in rodent models. While diet normalization largely allows for recovery from metabolic impairment, it remains unknown whether long-term hypothalamic inflammation induced by obesogenic diets is a reversible process. In this study, we aimed at determining sex specificity of hypothalamic neuroinflammation and gliosis in mice fed a fat- and sugar-rich diet, and their reversibility upon diet normalization. Mice were fed a 60%-fat diet complemented by a 20% sucrose drink (HFHSD) for 3 days or 24 weeks, followed by a third group that had their diet normalized for the last 8 weeks of the study (reverse diet group, RevD). We determined the expression of pro- and anti-inflammatory cytokines, and of the inflammatory cell markers IBA1, CD68, GFAP and EMR1 in the hypothalamus, and analyzed morphology of microglia (IBA-1+ cells) and astrocytes (GFAP+ cells) in the arcuate nucleus. After 3 days of HFHSD feeding, male mice showed over-expression of IL-13, IL-18, IFN-γ, CD68 and EMR1 and reduced expression of IL-10, while females showed increased IL-6 and IBA1 and reduced IL-13, compared to controls. After 24 weeks of HFHSD exposure, male mice showed a general depression in the expression of cytokines, with prominent reduction of TNF-α, IL-6 and IL-13, but increased TGF-ß, while female mice showed over-expression of IFN-γ and IL-18. Furthermore, both female and male mice showed some degree of gliosis after HFHSD feeding for 24 weeks. In mice of both sexes, diet normalization after prolonged HFHSD feeding resulted in partial neuroinflammation recovery in the hypothalamus, but gliosis was only recovered in females. In sum, HFHSD-fed mice display sex-specific inflammatory processes in the hypothalamus that are not fully reversible after diet normalization.

Shiitake mushroom-derived extracellular nanovesicles: Preparation, characterization, and inhibition of Caco-2 cells.

In this study, Shiitake mushroom-derived extracellular nanovesicles (SMDENVs) were isolated from fresh Shiitake mushrooms by ultracentrifugation and sucrose gradient ultracentrifugation. The morphological characteristics of SMDENVs were investigated via Transmission Electron Microscopy and Laser Scanning Confocal Microscopy. SMDENVs were spherical, hollow, and uniform in size, with an average diameter of 177.6 ± 51.4 nm. Based on the analysis of lipidomics and proteomics, 383 lipids species and 1290 proteins were identified in SMDENVs. Compared with the conventional liposomes, SMDENVs demonstrated higher stability in different environmental conditions. Furthermore, we observed that SMDENVs were cytocompatible and inhibited the proliferation of Caco-2 cells. SMDENVs could be phagocytized by Caco-2 cells in a time-dependent manner. Further, SMDENVs also inhibited the proliferation of Caco-2 cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC50) was 236.2 ± 3.2 µg/mL. Additionally, SMDENVs induced cellular apoptosis by increasing the levels of reactive oxygen species and decreasing the mitochondrial membrane potential.

Transcriptome Analysis Reveals the Mechanism of Cold-Induced Sweetening in Chestnut during Cold Storage.

Chestnuts become sweetened with better tastes for fried products after cold storage, but the possible mechanism is not clear. The dynamics of sugar components and related physiological responses, as well as the possible molecular mechanism in chestnuts during cold storage, were investigated. Sucrose accumulation and starch degradation contributed to taste improvement. Sucrose content reached the peak after two months of cold storage, along with the accumulation of reducing sugars of maltose, fructose and glucose to a much lesser extent. Meanwhile, alpha-amylase and beta-amylase maintained high levels, and the activities of acid invertase and sucrose synthase increased. Transcriptome data demonstrated that differentially expressed genes (DEGs) were significantly enriched in the process of starch and sucrose metabolism pathway, revealing the conversion promotion of starch to sucrose. Furthermore, DEGs involved in multiple phytohormone biosynthesis and signal transduction, as well as the transcription regulators, indicated that sucrose accumulation might be interconnected with the dormancy release of chestnuts, with over 90% germinated after two months of cold storage. Altogether, the results indicated that cold storage improved the taste of chestnuts mainly due to sucrose accumulation induced by DEGs of starch and sucrose metabolism pathway in this period, and the sweetening process was interconnected with dormancy release.

Interactions at the Oviposition Scar: Molecular and Metabolic Insights into Elaeagnus angustifolia's Resistance Response to Anoplophora glabripennis.

The Russian olive (Elaeagnus angustifolia), which functions as a "dead-end trap tree" for the Asian long-horned beetle (Anoplophora glabripennis) in mixed plantations, can successfully attract Asian long-horned beetles for oviposition and subsequently kill the eggs by gum. This study aimed to investigate gum secretion differences by comparing molecular and metabolic features across three conditions-an oviposition scar, a mechanical scar, and a healthy branch-using high-performance liquid chromatography and high-throughput RNA sequencing methods. Our findings indicated that the gum mass secreted by an oviposition scar was 1.65 times greater than that secreted by a mechanical scar. Significant differences in gene expression and metabolism were observed among the three comparison groups. A Kyoto Encyclopedia of Genes and Genomes annotation and enrichment analysis showed that an oviposition scar significantly affected starch and sucrose metabolism, leading to the discovery of 52 differentially expressed genes and 7 differentially accumulated metabolites. A network interaction analysis of differentially expressed metabolites and genes showed that EaSUS1, EaYfcE1, and EaPGM1 regulate sucrose, uridine diphosphate glucose, α-D-glucose-1P, and D-glucose-6P. Although the polysaccharide content in the OSs was 2.22 times higher than that in the MSs, the sucrose content was lower. The results indicated that the Asian long-horned beetle causes Russian olive sucrose degradation and D-glucose-6P formation. Therefore, we hypothesized that damage caused by the Asian long-horned beetle could enhance tree gum secretions through hydrolyzed sucrose and stimulate the Russian olive's specific immune response. Our study focused on the first pair of a dead-end trap tree and an invasive borer pest in forestry, potentially offering valuable insights into the ecological self-regulation of Asian long-horned beetle outbreaks.

Inhibitory Effects of Surface Pre-Reacted Glass Ionomer Filler Eluate on Streptococcus mutans in the Presence of Sucrose.

The surface pre-reacted glass ionomer (S-PRG) filler is a type of bioactive functional glass that releases six different ions. This study examined the effects of the S-PRG filler eluate on Streptococcus mutans in the presence of sucrose. In a solution containing S. mutans, the concentrations of BO33-, Al3+, Sr2+, and F- were significantly higher in the presence of the S-PRG filler eluate than in its absence (p < 0.001). The concentrations of these ions further increased in the presence of sucrose. Additionally, the S-PRG filler eluate significantly reduced glucan formation by S. mutans (p < 0.001) and significantly increased the pH of the bacterial suspension (p < 0.001). Bioinformatic analyses revealed that the S-PRG filler eluate downregulated genes involved in purine biosynthesis (purC, purF, purL, purM, and purN) and upregulated genes involved in osmotic pressure (opuAa and opuAb). At a low pH (5.0), the S-PRG filler eluate completely inhibited the growth of S. mutans in the presence of sucrose and significantly increased the osmotic pressure of the bacterial suspension compared with the control (p < 0.001). These findings suggest that ions released from the S-PRG filler induce gene expression changes and exert an inhibitory effect on S. mutans in the presence of sucrose.

High-Level Expression of Sucrose Isomerase in Bacillus subtilis Through Expression Element Optimization and Fermentation Optimization.

Sucrose isomerase is an important food enzyme that catalyzes the isomerization of sucrose into isomaltulose, a functional sugar widely used in food industry, while the production level of sucrose isomerase in food safe host strains was much lower than industrial requirement. Bacillus subtilis is an excellent host strain for recombinant protein expression, which owns the characteristics of powerful secretory capability and generally recognized as safe state. In this study, the expression of sucrose isomerase in B. subtilis was improved through expression element optimization and fermentation optimization. Firstly, the extracellular chaperone PrsA was overexpressed to enhance extracellular folding of sucrose isomerase, which improved the recombinant expression level by 80.02%. Then, the protein synthesis level was optimized through promoter screening, improving the recombinant expression level by 60.40%. On the basis of strain modification, the fermentation conditions including nitrogen source, carbon source, metal ion, pH and temperature were optimized successively in shake-flask. Finally, the 3 L bioreactor cultivation condition was optimized and yielding a sucrose isomerase activity of 862.86 U/mL, the highest level among the food safety strains. This study provides an effective strategy to improve the expression level of food enzymes in B. subtilis.