Search Results (182)

Unlike conventional energy-intensive physical/chemical soil remediation, dietary regulation of As oral bioavailability represents a cost-effective, sustainable downstream intervention in environmental risk management and control. However, how distinct dietary structures regulate As bioavailability remains unelucidated, hindering a holistic understanding of corresponding exposure and health risks. To address this, a mouse bioassay was conducted to evaluate the relative bioavailability (RBA) of As in two soils with four typical diet structures (high-fat, high-protein, high-carbohydrate, and high-dietary fiber diets). The results showed that although the four diets promoted the gastrointestinal As dissolution by 1.1–1.7-fold, the high-dietary fiber diet decreased As-RBA by 9.49–13.2% and lowered the health risk by 0.50–0.70-fold, which was more effective than high-protein and high-carbohydrate diets. The decrease was associated with lower intestinal permeability, which correlated with a significant increase in the relative abundance of Roseburia and Lachnospiraceae, and a decrease in the apoptosis rate of mouse intestinal epithelial cells. In contrast, a high-fat diet increased As-RBA by 8.72–11.9% and raised the health risk by 1.33–1.38-fold, which was associated with a significant proliferation of Dubosiella and a significant inhibition of Roseburia. This study shows that a high-dietary fiber diet is associated with reduced As exposure and potential health risks, in parallel with favorable changes in gut microbiota, oxidative status, and intestinal permeability. Full article

Background/Objectives: Sunflower (Helianthus annuus L.) is one of the four major oil crops worldwide and possesses strong stress tolerance. However, salt stress remains limiting in the improvement of sunflower yield and quality. Methods: In this study, the salt-tolerant cultivar P50 and salt-sensitive cultivar P29 were used as experimental materials to conduct transcriptome sequencing on root and leaf samples treated with NaCl. Subsequently, the molecular mechanisms underlying salt tolerance in sunflower were revealed through assembly and splicing, functional annotation, differential expression analysis, enrichment analysis, and transcription factors (TFs) prediction. Results: Results showed that 54,860,184 and 60,601,572 high-quality clean reads were obtained from the two cultivars, respectively. A total of 110,751 all-unigenes were generated after assembly and clustering, of which 77,536 were functionally annotated. A total of 21,332 differentially expressed genes (DEGs) were identified, including 10,306 upregulated and 11,026 downregulated genes. Quantitative real-time PCR validation of 15 DEGs showed a 93.33% consistency rate with the sequencing data. GO enrichment analysis indicated that DEGs were significantly enriched in pathways related to antioxidant enzyme activities. KEGG enrichment analysis demonstrated that DEGs were primarily involved in 15 carbohydrate metabolism pathways, especially starch and sucrose metabolism. In addition, 67 differentially expressed TF families containing 528 DEGs were identified, including bHLH, AP2/ERF-ERF, MYB, C3H, WRKY, EREBP, B3-ARF, and NAC. Conclusions: Our study constructed a comprehensive transcription map of the sunflower response to salt stress and systematically elucidated the molecular mechanisms underlying salt tolerance. The salt-tolerant sunflower cultivar P50 exhibits an efficient salt stress defense system via three core strategies: (i) activating the antioxidant system to rapidly scavenge excess reactive oxygen species and mitigate oxidative damage; (ii) regulating carbohydrate metabolism through starch and sucrose redistribution to provide energy and osmotic protection against physiological drought; and (iii) mobilizing multiple TF families to establish a complex regulatory network for the precise control of downstream functional genes. Full article

Soybean (Glycine max) is a vital food and oil crop in China, yet its yield and quality are severely threatened by piercing–sucking damage caused by Riptortus pedestris (Hemiptera: Alydidae) to soybean pods. Under global climate warming and expanded soybean cultivation, temperature has become a key environmental factor driving the spread of and aggravated damage caused by R. pedestris. We investigated the effects of temperature (32, 36, 40, 42, and 44 °C) and exposure duration (1–4 h) on the energy substances and antioxidant enzyme activities in adult R. pedestris. These two factors also had significant effects on the pest’s energy substances and antioxidant defense. Under short-term high-temperature stress, the water loss rate and fat, total sugar, and glycogen contents increased significantly, while protein content showed a fluctuating upward trend, with distinct sexual differences in these responses; the water loss and energy substance levels within the lethal high-temperature range, around 44 °C, were generally higher than those in the sublethal range (36–42 °C). R. pedestris showed physiological changes consistent with enhanced heat tolerance and adaptability, including water balance regulation, carbohydrate and lipid accumulation, and modulation of protein synthesis and degradation. In the sublethal high-temperature range, antioxidant enzyme activity patterns were altered, and SOD activity was increased; meanwhile, the MDA content also rose, and POD and CAT activities decreased. In the lethal high-temperature range, the overall antioxidant enzyme activities were lower than in the suitable temperature range, with the POD activities and MDA content still rising. These results suggest that the dynamic adjustment of antioxidant enzyme activities may contribute to alleviating oxidative damage and rapid adaptation to temperature-induced oxidative stress in R. pedestris. These findings indicate that R. pedestris possesses physiological plasticity to cope with sublethal heat stress through metabolic reallocation and antioxidant defense activation, but extreme temperatures cause severe physiological disruption. This study provides insights into the thermal biology and heat resistance mechanisms of this pest under climate warming scenarios. Full article

Fluopyram (FO), a widely used succinate dehydrogenase inhibitor (SDHI) fungicide, poses a potential risk to aquatic ecosystems due to its mitochondrial toxicity in non-target organisms. This study investigated its toxic effects on zebrafish (Danio rerio). Embryos (n = 30 per concentration) were exposed to FO (0, 0.375, 0.75, 1.5 mg/L) for 96 h, resulting in concentration-dependent developmental toxicity, including increased malformations, reduced heart rate, and inhibited swimming behavior. Adult zebrafish were chronically exposed to lower concentrations (0, 0.01, 0.1, 1.0 mg/L; n = 20 per concentration per replicate) for 28 days. Biochemical analyses across both life stages revealed that FO significantly inhibited succinate dehydrogenase (SDH) activity and mitochondrial complex II, reduced ATP levels, and induced oxidative stress. Integrated transcriptomic and metabolomic analyses showed that FO profoundly perturbed specific metabolic pathways, primarily glutathione metabolism, cytochrome P450-mediated detoxification, and core nutrient metabolism pathways involving carbohydrates, lipids, and amino acids. In adults, chronic exposure induced significant hepatotoxicity, evidenced by histopathological damage, altered liver enzyme activities (GPT/GOT), and activation of autophagy and PPAR/FoxO signaling pathways. Our results demonstrate that FO induces multifaceted toxicity in zebrafish, from developmental defects to hepatic metabolic dysfunction, primarily driven by mitochondrial impairment and oxidative stress. This study provides crucial mechanistic hazard data and insights for the ecological risk assessment of SDHI fungicides. Full article

Oxidative catalytic fractionation (OCF) under the lignin-first strategy has emerged as a critical technological approach for biomass refining. To address the inevitable carbohydrate degradation and lignin condensation in conventional OCF, this study designed a cobalt-doped layered double hydroxide oxide (Co-LDO) catalyst compatible with non-alkaline (without Brønsted bases) organic systems, which exhibits excellent performance in poplar biomass OCF. With a straightforward preparation process, the Co-LDO catalyst yields high-content oxidized lignin oligomers while efficiently retaining carbohydrates, providing feedstock rich in carbohydrates (cellulose and hemicellulose) for the subsequent production of bioenergy and biomass-based chemicals. Under optimized conditions screened via systematic reaction condition investigation and metal-doped LDO catalyst evaluation, the process achieved a 94.01 wt% delignification rate, with 72.19 wt% of lignin converted into lignin oligomer oil, supported by detailed product composition and structural characterization. Meanwhile, 74.14 wt% hemicellulose and 98.23 wt% cellulose were recovered in solid residues, with structurally intact hemicellulose retention being 2.3 times higher than in traditional OCF. Mass balance calculation confirmed a total poplar refining yield of 81.58 wt%. In summary, this Co-LDO-catalyzed OCF strategy provides a high-activity non-precious metal system, effectively suppressing lignin condensation while preserving high-yield carbohydrates, realizing the efficient full-component refining of poplar biomass. Full article

Foliar fertilization, an efficient agricultural production strategy, is relatively rare in bamboo cultivation and management. Phosphorus assumes an indispensable role in controlling plant sugar metabolism and antioxidant defense. Whether foliar application of triple superphosphate (TSP) can enhance carbohydrate metabolism in new bamboo leaves, improve the antioxidant defense system, and thereby promote the growth and development of new leaves remains to be investigated. In this study, we conducted foliar application of TSP on the new leaves of 1-year-old Neosinocalamus affinis culms to analyze the effects of exogenous phosphorus on leaf morphological, anatomical, and physiological characteristics. The results showed that 0.3% TSP was the optimal concentration. This treatment significantly increased leaf length (maximum growth rate of 24.3% on day 21) and mesophyll cell thickness. It also significantly increased total chlorophyll content (maximum increase rate of 71.10% on day 14). The 0.3% TSP treatment significantly enhanced the activities of critical enzymes involved in sucrose biosynthetic and catabolic processes and starch synthesis, inhibited starch degrading enzyme activity, and promoted the accumulation of soluble sugars, starch, and total non-structural carbohydrates. Furthermore, TSP treatment significantly increased the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), and significantly reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) (45.11% and 54.64% reduction on day 7, respectively), indicating effective alleviation of oxidative stress and enhanced leaf stress resistance. Generally, foliar application of 0.3% TSP synergistically optimized leaf structure, photosynthetic capacity, sugar metabolism, and antioxidant defense system, comprehensively promoting the development of new N. affinis leaves and enhancing their stress resistance. Full article

Biogenic carbon dots (CDs) are emerging as promising plant biostimulants, yet their effects during early crop establishment remain underexplored. Here, we synthesized and characterized Spirulina-derived CDs and evaluated their efficacy as seed nanopriming agents in rice (Oryza sativa L.). CDs exhibited nanoscale size, abundant surface functionalities, and a highly negative ζ-potential, indicative of stable aqueous dispersions. Spectroscopic characterization (Raman and FTIR) confirmed a graphitic–amorphous carbon structure. Near-infrared spectroscopy coupled to principal component analysis revealed time-dependent metabolic changes during imbibition, identifying 8–12 h as the optimal priming window. Nanopriming with Spirulina CDs (0.2 mg mL⁻¹ for 12 h) increased the seed germination rate (25%), the germination speed index (17%), vigor index I (22%), and root length (37%) compared to hydropriming. Biochemically, the nanoprimed seedlings accumulated higher levels of starch (24%), total carbohydrates (8%), and total phenolics (20%), without evidence of oxidative imbalance, based on antioxidant capacity measurements and proteomic profiling. Proteomic analysis revealed coordinated metabolic reprogramming, characterized by increased abundance of proteins involved in translation, energy metabolism, and ion/nutrient homeostasis, alongside reduced abundance of proteins associated with defense and catabolic processes. This shift from stress-preparation to growth-oriented metabolism supports improved seedling establishment. Overall, Spirulina-derived CDs function as effective nanobiostimulants that promote early metabolic activation and resource mobilization, offering a sustainable strategy to enhance rice seedling establishment. Full article

In the context of global climate change, the co-occurrence of salt and heat stress represents a major constraint to rice production, resulting in greater yield penalties than either stress alone. This study aimed to assess the effects of salt and heat stress on oxidative homeostasis, photosynthetic performance, carbon (C)–nitrogen (N) metabolism, and rice yield. The experiment comprised four treatments, i.e., control (CK), salt (irrigation with 3.9 dS m⁻¹ NaCl solution), heat (exposure to 36 °C/30 °C day/night for 5 days at panicle initiation), and combined salt + heat stress. Results showed that combined stress enhanced reactive oxygen species (ROS) accumulation (i.e., H₂O₂ content and O₂⁻ contents were 1.3 and 1.5 times higher than CK), and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were increased by 64.6%, 69.5%, and 74.8% higher than CK. At the molecular level, salt + heat stress upregulated antioxidant defense-related genes, i.e., OsAPX2, OsSODCC1, and OsAPX1, while significantly downregulated ion homeostasis-related genes, i.e., OsSOSs, OsHKT1;3, OsHKT1;5, and OsNHX4, and photosynthesis-related genes, i.e., Ospsbo, OsRbcS2, and OsRbcS3, compared with CK. Furthermore, salt + heat stress reduced the activities of C-metabolism enzymes (sucrose phosphate synthase, sucrose synthase, and starch synthase) and N-metabolism enzymes (nitrate reductase, glutamine synthetase, and glutamate synthase), leading to 34.3% and 18.6% lower stem-sheath non-structural carbohydrate accumulation in stem sheath and its translocation rate, respectively, while total N accumulation decreased by 42.9%, as compared with CK. Ultimately, these cascading effects inhibited panicle development and reduced yield. The findings provide a theoretical basis for improving rice tolerance to combined abiotic stresses by targeting oxidative stress mitigation, photosynthetic protection, and key stress-responsive gene regulation. Full article

The emission of nitrogen oxides (N₂O) in rivers is an important source of potent greenhouse gases. However, the mechanism at the interface between rivers and riverbanks remains unclear. This study quantified N₂O emissions from natural and artificial riparian zones across seasons and explored the microbial mechanisms affecting N₂O production and consumption in an intensive agricultural river network in China. Significant seasonal variability in N₂O emission rates was observed (p < 0.05), with mean values of 0.56 ± 0.09 mmol·m⁻²·h⁻¹ in autumn and 1.13 ± 0.32 mmol·m⁻²·h⁻¹ in spring. In spring, emissions from natural riparian zones (1.38 ± 0.28 mmol·m⁻²·h⁻¹) were significantly higher than those from artificial riparian zones (0.89 ± 0.05 mmol·m⁻²·h⁻¹). All wind-based models significantly overestimated N₂O emissions (p < 0.05) due to inflated IPCC emission factors (EF_5r), exceeding measured values by 1.76–3.09 times. Dissolved organic carbon and nitrite nitrogen were identified as key environmental drivers of N₂O emissions. Nitrogen fixation and ammonification accounted for 82.3% of N₂O production. Network analysis revealed a dominant microbial niche containing nitrifiers, sulfate-reducing bacteria, and carbohydrate-degrading taxa. Partial least squares path modeling indicated that riparian zone type altered DOC and NO₂⁻ availability, regulated nifH and ureC gene abundances, and enhanced N₂O production. These findings underscore the importance of riparian-zone-specific microbial regulation of riverine N₂O emissions and demonstrate the necessity of refining EF_5r estimates for agricultural river networks. Full article

Drought stress significantly limits crop yield by disturbing plant water status and redox homeostasis, leading to oxidative stress and growth suppression. Anthocyanins, with their strong antioxidant properties, are closely linked to abiotic stress adaptation. The R2R3-MYB transcription factor SlANT1 promotes anthocyanin biosynthesis in tomato, yet its role in drought resistance remains poorly understood. This study explored the function of SlANT1 in tomato under drought conditions. SlANT1 expression was upregulated under both drought and high salinity. The overexpression of SlANT1 resulted in higher anthocyanin accumulation and reduced leaf and stem dimensions. Under drought, SlANT1-overexpression (SlANT1-OE) plants maintained a greater leaf relative water content, showed less negative water potential, wilted less, and recovered faster after rewatering. These plants also accumulated lower levels of reactive oxygen species (ROS) and malondialdehyde (MDA). While antioxidant enzyme activities were generally reduced, anthocyanin-dependent ROS scavenging was significantly enhanced. SlANT1 overexpression also modulated carbohydrate metabolism and aquaporin gene expression, elevating sucrose, fructose, glucose, and soluble protein while decreasing starch, thereby supporting osmotic adjustment. Notably, while stomata remained partially open in SlANT1-OE plants during drought, they exhibited reduced stomatal density, which likely compensated for the wider apertures and helped maintain favorable water status, while still sustaining higher photosynthetic rates and photosystem II integrity. These findings demonstrate that SlANT1 enhances drought tolerance through coordinated mechanisms involving anthocyanin-mediated antioxidant protection, improved water relations, and the reprogramming of carbohydrate and aquaporin pathways. SlANT1 thus represents a promising target for breeding drought-resilient, high-anthocyanin tomato varieties. Full article

Background/Objectives: Exercise calorimetry provides a means to quantify the relative contributions of lipid and carbohydrate (CHO) oxidation across a range of exercise intensities. Although lipid oxidation capacity has been widely studied—particularly in relation to exercise prescription for individuals with obesity—the factors governing CHO oxidation during exercise are less clearly defined. This study therefore aimed to investigate, within a large single-center cohort, not only the established determinants of maximal lipid oxidation (LIPOXmax) but also those influencing CHO oxidation. Methods: Exercise calorimetry was performed in a cohort of 6465 individuals (4561 women and 1904 men; mean age 46.5 years; mean BMI 33.6 kg/m²). Two principal physiological indices were derived: LIPOXmax, defined as the exercise intensity eliciting maximal rates of fat oxidation, and the carbohydrate cost of the watt (CCW), defined as the slope characterizing the relationship between CHO oxidation and power output. Results: LIPOXmax showed positive associations with lean and muscle mass, and negative associations with fat mass and age, supporting the notion that greater muscle mass enhances the capacity for fat oxidation. Although men demonstrated higher absolute maximal fat oxidation rates, adjustment for body composition revealed that women exhibited relatively higher lipid oxidation (+30%, p < 0.001), occurring at a greater percentage of $\dot{\mathrm{V}}$O_2max (+9.2%, p < 0.001). Furthermore, the carbohydrate cost of the watt was significantly elevated in women (+17.8% compared with men). CCW was positively correlated with BMI, fat mass, and age, and negatively correlated with muscle mass, LIPOXmax, and the crossover point—that is, the exercise intensity at which CHO becomes the predominant substrate. Discussion and Conclusions: Individuals with higher adiposity exhibited a greater reliance on carbohydrate oxidation, whereas leaner individuals preferentially oxidized lipids at comparable exercise intensities. These observations reinforce the reciprocal interplay between lipid and carbohydrate metabolism during exercise and highlight the substantial influence of body composition, age, and sex. Notably, this study provides the first comprehensive characterization of the determinants of CHO oxidation during exercise, identifying sex, age, and adiposity as major contributing factors. This underexplored facet of metabolic flexibility may hold practical relevance in clinical contexts such as obesity or susceptibility to exercise-induced hypoglycemia. Full article

This study explores the potential of pine bark—a highly accessible and underexploited by-product of forestry and food processing—as a renewable raw material for rigid polyurethane (PUR) foam production. Under optimal extraction conditions, water-soluble extractives rich in carbohydrates were isolated from biomass with a yield of 25% and subsequently condensed with propylene carbonate (PC) to produce bio-based polyols. The polyols synthesized at a PC/OH molar ratio ranging from 1 to 5 were incorporated into rigid PUR foam formulations as substitutes for commercial polyether polyols. The foams containing bio-polyols synthesized at a PC/OH ratio of 3 demonstrated the highest compressive strength and thermal insulation performance, exceeding those of the reference material by 30% and 9%, respectively, and exhibited enhanced thermo-oxidative stability. Incorporation of extracted bark up to 10 wt% as a filler in the PUR matrix led to a decrease in mechanical properties to the level of the reference foam and a 19% reduction in thermal insulation capacity, without affecting the closed-cell content. Cone calorimetry revealed that both filled and unfilled bio-polyol-based PUR foams exhibited lower degradation rate, heat release rate, and total smoke release compared with the reference material, indicating reduced flammability and a lower tendency toward fire propagation. Full article

Callus induction is the foundation for large-scale and rapid plant propagation, and explant age is a key factor affecting callus induction efficiency and in vitro culture outcomes. Pedicels are the main explants for Agapanthus praecox tissue culture. This study analyzed three pedicel developmental stages (S1: immature, S2: semi-mature, S3: mature) and their induced calli (C1, C2, C3). We integrated transcriptomics, metabolomics (LC-MS/GC-MS), quantitative real-time PCR (qRT-PCR), and weighted gene co-expression network analysis (WGCNA) to clarify the physiological and molecular mechanisms of pedicel regenerative potential. Results showed that S2 exhibited the highest callus induction rate, while C2 showed superior proliferation coefficients and regenerative potential. In pedicel samples, differentially expressed genes were significantly enriched in the MAPK signaling pathway and plant hormone signal transduction pathway, while differentially accumulated metabolites were linked to energy metabolism, amino acid/nucleotide metabolism, and stress responses. Key metabolites (e.g., carbohydrates, amino acids, thidiazuron, and β-chlorogenin) played specific roles in maintaining the meristematic capacity of pedicels. qRT-PCR further confirmed that S2 maintained balanced endogenous hormone signaling and proper cell wall modification. Furthermore, WGCNA identified a key module associated with oxidative stress responses along with S2. Overall, the regenerative potential of pedicel is mediated by the balanced hormone signal transduction, metabolic reprogramming, and epigenetic regulation in A. praecox. Full article

Background: Long pulse width stimulation (LPWS; 120–150 ms) has the potential to stimulate denervated muscles in persons with spinal cord injury (SCI). We examined whether testosterone treatment (TT) + LPWS would increase skeletal muscle size, leg lean mass and improve overall metabolic health in SCI persons with denervation. We hypothesized that one year of combined TT + LPWS would downregulate gene expression of muscle atrophy and upregulate gene expression of muscle hypertrophy and increase mitochondrial health in SCI persons with lower motor neuron (LMN) injury. Methods: Ten SCI participants with chronic LMN injury were randomized into either 12 months, twice weekly, of TT + LPWS (n = 5) or a TT+ standard neuromuscular electrical stimulation (NMES; n = 5). Measurements were conducted at baseline (week 0), 6 months following training (post-intervention 1), and one week following 12 months of training (post-intervention 2). Measurements included body composition assessment using magnetic resonance imaging (MRI) and dual x-ray absorptiometry (DXA). Metabolic profile assessment encompassed measurements of resting metabolic rate, carbohydrate and lipid profiles. Finally, muscle biopsy was captured to measure RNA signaling pathways and mitochondrial oxidative phosphorylation. Results: Compliance and adherence were greater in the TT + NMES compared to the TT + LPWS group. There was a 25% increase in the RF muscle CSA following P1 measurement in the TT + LPWS group. There was a recognizable non-significant decrease in intramuscular fat in both groups. There was a trend (p = 0.07) of decrease in trunk fat mass following TT + LPWS, with an interaction (p = 0.037) in android lean mass between groups. There was a trend (p = 0.08) in mean differences in DXA-visceral adipose tissue (VAT) between groups at P1 measurements. For genes targeting muscle atrophy, TT + LPWS showed a trending decline in MURF1 and FOXO3 genes returning to similar levels as TT + NMES before 12 months. Conclusions: These pilot data demonstrated the safety of applying LPWS in persons with SCI. Six months of TT + LPWS demonstrated increases in rectus femoris muscle CSA. The effects on muscle size were modest between groups. Signaling pathway analysis suggested downregulation of genes involved in muscle atrophy pathways. Future clinical trials may consider a home-based approach with more frequent applications of LPWS. Full article

This study investigated the effects of dietary carbohydrate levels on growth performance, body composition, and hepatic expression of metabolic genes in Chinese hook snout carp (Opsariichthys bidens). Fish were fed five isonitrogenous diets with graded α-starch levels (8%, 14%, 20%, 26%, and 32%) for 56 days. The diet containing 14% α-starch significantly increased the weight gain rate (WGR) and specific growth rate (SGR) of O. bidens (p < 0.05). Both broken-line and polynomial regression analyses on WGR and SGR consistently indicated an optimal dietary α-starch level of approximately 14–17%. High carbohydrate diets significantly elevated plasma glucose, triglyceride, and cholesterol levels, as well as hepatosomatic and intraperitoneal fat indices. Gene expression analysis revealed that moderate carbohydrate intake upregulated lipoprotein lipase (lpl), hormone-sensitive lipase (hsl), and carnitine palmitoyltransferase 1 (cpt1) gene expressions, enhancing lipolysis and β-oxidation, whereas excessive carbohydrate intake (>26% α-starch) suppressed these pathways but strongly induced acc1 gene expressions, promoting lipogenesis. Additionally, glycogen metabolism genes (glycogen synthase (gys) and glycogen phosphorylase (pyg) and glycolysis-related phosphofructokinase (pfk) were responsive to carbohydrate supply, while oxidative metabolism gene cs was downregulated under excessive carbohydrate, implying reduced mitochondrial oxidative metabolism. Overall, O. bidens exhibited limited carbohydrate utilization, with optimal intake supporting growth and metabolic balance, whereas excessive intake redirected glucose toward glycogen and lipid accumulation, leading to metabolic imbalance. Full article