Search Results (68)

The ‘Mollar de Elche’ pomegranate cultivar is highly valued for its organoleptic properties, yet it often suffers from inadequate fruit pigmentation, reducing its commercial competitiveness. This study, carried out in a mature commercial orchard located in Spain (Alicante), evaluated the impact of preharvest applications of sorbitol at different concentrations (0, 0.1, 0.5, and 1% in 2023, and 2.5 and 5% in 2024) and three application periods: S1 (nine applications from fruit set), S2 (six applications from seed hardening), and S3 (three applications at the onset of colour change) over two consecutive growing seasons (2023 and 2024). Treatments were applied via foliar spraying from the time of fruit set until the onset of external colour change. The results showed that sorbitol acted as an effective metabolic ‘vector’, significantly increasing fruit weight and total yield, particularly at concentrations of 1 and 5%. Furthermore, sorbitol treatments enhanced fruit firmness by stabilizing cell wall structures and significantly improved exocarp red pigmentation by reducing the hue angle. While the highest doses (1, 2.5, and 5%) enhanced biomass accumulation, they also triggered a potential negative feedback loop in sugar sensing that could interfere with secondary metabolism at excessive thresholds. These findings suggest that preharvest sorbitol applications, particularly at concentrations between 1 and 5% starting from early application period (S1), serve as an effective strategy for improving yield and external pigmentation in ‘Mollar de Elche’ pomegranate fruit. Full article

Background: Neuroblastoma (NB) progression is influenced by metabolic and redox adaptations. The polyol pathway, driven by aldose reductase (AKR1B1) and sorbitol dehydrogenase (SORD), is activated in hyperglycemic conditions, while detoxification of lipid peroxidation products such as 4-hydroxynonenal (4-HNE) involves carbonyl reductase 1 (CBR1) and AKR1B1. A systematic characterization of these enzymes under distinct metabolic and oxidative challenges in NB is currently lacking. Methods: Human neuroblastoma LAN-5 and SH-SY5Y cells were exposed to hyperglycemic medium to assess polyol pathway regulation, and to exogenous 4-HNE to model aldehyde-induced oxidative stress. Protein expression and enzyme activities were quantified. Cells were treated with Sorbinil or rutin during stress exposure, and viability was analyzed in 2D and 3D models. Results: Hyperglycemia increased AKR1B1 activity and sorbitol accumulation, indicating polyol pathway activation in NB cells. Both NB cell lines displayed an incomplete HNE-detoxifying enzyme profile, with absence of ALDH1A1 and AKR1C3 expression. Exposure to 4-HNE reduced NB cell viability both in 2D and 3D models. Pharmacological inhibition of AKR1B1, but not of CBR1, exacerbated 4-HNE-mediated cytotoxicity. Conclusions: While hyperglycemia stimulates the polyol pathway, aldehyde detoxification by AKR1B1 supports resistance to 4-HNE toxicity, demonstrating that AKR1B1 activity is essential to counteract HNE toxicity, and its impairment may increase the susceptibility of NB cells to oxidative damage. Full article

Cyrtorhinus lividipennis, a key natural enemy of the brown planthopper, Nilaparvata lugens, has been observed to tolerate short-term high-temperature exposure; however, the physiological and molecular mechanisms underlying this heat tolerance remain unclear, which may hinder its effective conservation and utilization. Here, we combined physiological and biochemical assays with transcriptome sequencing to elucidate the physiological and molecular mechanisms of heat tolerance in C. lividipennis following 1 h exposure to three temperatures: 26 °C (control), 33 °C (moderate heat stress), and 40 °C (severe heat stress). At 40 °C, sorbitol, trehalose, lipid, and glycogen contents increased significantly, whereas glycerol levels declined. Transcriptomic profiling revealed temperature-dependent DEGs enriched in starch and sucrose metabolism, galactose metabolism, glycerolipid metabolism, oxidative phosphorylation, and protein folding, sorting, and degradation, with pronounced temperature-dependent upregulation of heat shock protein (HSP) gene families. Together, these results demonstrate that C. lividipennis coordinates its heat stress response through soluble polyol accumulation, which is known to act as a compatible osmolytes that help stabilize proteins and membranes and mitigate thermal damage, energy metabolic reprogramming, and HSP-mediated proteostasis, thereby providing a theoretical basis for its conservation and utilization in sustainable paddy agroecosystems. Full article

Diabetic retinopathy (DR) is a major microvascular complication of type 2 diabetes (T2D) and is strongly associated with chronic inflammation. Neutrophils contribute to this inflammatory milieu, and the hyperosmolar stress-responsive transcription factor NFAT5 and its downstream effector aldose reductase (AR) may play crucial roles in this process. NFAT5 regulates AR, which converts glucose to sorbitol; excessive sorbitol accumulation promotes endothelial and retinal cell damage. Given the links between NFAT5, metabolic stress and immune activation, dysregulation of the NFAT5–AR axis in neutrophils may contribute to DR pathophysiology. This study evaluated NFAT5 and AR expression in peripheral blood neutrophils from 150 individuals classified as nondiabetic (n = 50), T2D without DR (n = 50), or T2D with DR (n = 50). Clinical, metabolic, and ophthalmic assessments were performed, and neutrophils were isolated to quantify NFAT5 and AR via ELISA. Associations with renal function, plasma osmolarity (pOSM), and hematological inflammatory ratios (NLR, NMR, NPAR, and SII) were analyzed. T2D-DR subjects presented impaired renal parameters, increased pOSM, reduced eGFR, and elevated NLR and NPAR. NFAT5 and AR levels were significantly increased in T2D-DR neutrophils and correlated positively with pOSM and the inflammatory ratios, whereas NFAT5 correlated inversely with the eGFR. These findings suggest that activation of the NFAT5–AR pathway contributes to neutrophil-driven inflammatory and hyperosmolar dysregulation in T2D and may influence DR progression. Full article

Silicon (Si) plays a critical role in regulating plant physiological processes, particularly through its influence on non-enzymatic antioxidant systems and amino acid metabolism. This study aims to assess soybean performance in response to both soil and foliar Si applications under well-watered and drought conditions, with the goal of enhancing Si accumulation in plant tissues and potentially strengthening the crop’s physiological responses to water deficit stress. This is especially pertinent given that the mechanisms underlying Si fertilization and its contribution to drought tolerance in soybean remain poorly understood. Greenhouse experiments were conducted using a 3 × 2 factorial design. The factors were: (i) three foliar Si treatments: control (no Si), potassium silicate (SiK; 128 g L⁻¹ Si, 126.5 g L⁻¹ K₂O, pH 12.0), and sorbitol-stabilized potassium silicate (SiKe; 107 g L⁻¹ Si, 28.4 g L⁻¹ K₂O, 100 mL L⁻¹ sorbitol, pH 11.8); and (ii) two soil water levels: well-watered (80% field capacity) and water-restricted (40% field capacity), the latter simulating tropical dry spells. Silicon was applied to the soil via irrigation and to the leaves via foliar spraying prior to the onset water restriction. All Si solutions were adjusted to pH 7.0 with 1 M HCl immediately before application. Potassium (K) levels were standardized across treatments through supplementary applications of KCl to both soil and foliage. Biometric and physiological parameters were subsequently measured. Sorbitol-stabilized Si enhanced Si accumulation in soybean tissues and improved plant resilience under both well-watered and drought conditions by promoting key physiological traits, including increased levels of daidzein and ascorbic acid levels, along with reduced amino acid concentrations. It also improved biometric parameters such as leaf area, root development, and number of pods per plant. These findings further support the role of Si as a beneficial element in enhancing stress tolerance and contributing to sustainable agricultural practices. Full article

Background: Diabetes mellitus is a multifactorial disease characterized by complex metabolic dysfunctions and chronic complications induced by hyperglycaemia. The design of multitarget ligands, capable of simultaneously controlling different pathogenic processes, was proposed as a promising approach to identify novel antidiabetic drugs endowed with improved efficacy. Methods: (5-Arylidene-4-oxothiazolidin-3-yl)alkanoic acid derivatives 1a–g and 2a–g were synthesized as potential multitarget antidiabetic agents. They were tested in vitro as inhibitors of both human recombinant AKR1B1 and PTP1B, and kinetic studies and molecular docking simulations for both enzymes were performed. Their effects on cellular glucose uptake, insulin signalling, and mitochondrial potential were assayed in cultures of murine C2C12 myocytes. A lipid accumulation assay was performed in HepG2 liver cells. The effects on high glucose-induced sorbitol accumulation were evaluated in lens HLE and retinal MIO-M1 cells. Results: All compounds displayed excellent AKR1B1 inhibitory activity (IC₅₀ 0.03–0.46 μM 1a–g; IC₅₀ 0.48–6.30 μM 2a–g); 1g and 2e–g also appreciably inhibited PTP1B at micromolar concentrations. Propanoic derivatives 2e–g significantly stimulated glucose uptake in C2C12 myocytes, in an insulin-independent way, reduced lipid accumulation in HepG2 liver cells, and caused hyperpolarization of C2C12 mitochondria at 10 μM concentration. Derivative 2e significantly reduced sorbitol accumulation in both HLE and MIO-M1 cells at a 5 μM concentration. Conclusions: The results reported here provided new insights into the mechanisms of action and structure/activity relationships of 4-thiazolidinone derivatives, underscoring the capability of compounds 2e–g of eliciting insulin-mimetic effects independent of hormone signalling. Among them, compound 2e also proved to inhibit AKR1B1-dependent sorbitol accumulation and, thus, emerged as a promising multitarget agent that can be considered for further investigations. Full article

Coffee Coffea arabica L. depends on abundantly distributed rainfall, and drought negatively impacts plant development, fruit production, bean quality, and, ultimately, beverage quality. Plant biotechnology by means of genetic manipulation and plant regeneration by the somatic embryogenic process is an alternative technology to overcome these problems. In the present work, we used the molecular approach of the Trehalase gene silencing to allow trehalose accumulation favoring plants surviving in extreme drought/salt environments. We used a cassette containing the antisense C. arabica L. Trehalase gene under the RD29 promoter from A. thaliana and the NOS terminator to genetically modify an embryogenic coffee C. arabica L. cv Typica line under osmotic stress supplemented with mannitol (0.3 M) and sorbitol (0.3 M). Osmotic stress-tolerant somatic embryos lines were recovered and regenerated into plants. Tolerant somatic embryo lines showed a higher rate of competence to induce secondary SE capacity and plants robustness. These lines showed a down-regulation of the Trehalase; accumulation of trehalose, sucrose, starch, and proline; higher photosynthetic rate; improved water-use efficiency; and appropriated vapor deficit pressure under soil conditions. A transcriptome analysis was performed from highly competent somatic embryogenic lines to understand the molecular mechanisms underlying osmotic-stress tolerance. From the up-regulated genes, a PPI network made by STRING v12.0 with high confidence (0.700) revealed the presence of the 10 modules: the cell cycle, chromatin remodeling, somatic embryogenesis, oxidative stress, generic transcription pathway, carbon metabolism, phenylpropanoid biosynthesis, trehalose biosynthesis, proline biosynthesis, and glycerolipid metabolism. Full article

Sand pear is a fruit tree crop with high economic value, widely cultivated in East Asia. However, ripening fruits often suffer from high-temperature stress, which has adverse effects on the quality and yield of the fruit. In this study, we perform high-temperature treatment on mature stage ‘Housui’ pear fruits. The results showed that heat stress decreased fruit firmness and mineral elements, as well as lead to the flesh appearance of watercore. High temperature induces H₂O₂, MDA, and the antioxidant enzyme activity including SOD, APX, POD, and CAT were significantly increased. Transcriptome and metabolomic analyses revealed that heat stress up-regulated genes related to sucrose synthesis (SPS) while down-regulating those involved in sucrose degradation (SS and NI), resulting in sucrose accumulation. Moreover, the expression of sorbitol dehydrogenase (SDH) and sorbitol transporter (SOT) genes was markedly suppressed, leading to sorbitol accumulation and impaired transport, which promoted watercore development. High temperature also stimulated the expression of ethylene synthesis genes, accelerating abnormal ripening of fruits. In addition, high temperature decreased the accumulation of organic acid and bioactive compounds. Additionally, several antioxidant enzymes genes, five heat shock transcription factors (HSFs) and 34 heat shock protein (HSP) genes were significantly up-regulated. Together, these findings provided new insights into the transcriptional response and metabolomic reprogramming of sand pear response to high-temperature stress. Full article

Drought stress poses a significant threat to tree growth, making the development of drought-resistant species essential for ecological restoration. WRKY transcription factors are critical regulators of plant drought responses; however, the role of WRKY22 in the woody species Populus ussuriensis K. remains unclear. In this study, the PuWRKY22 gene was cloned from P. ussuriensis via homologous cloning and was found to be highly expressed in leaves and responsive to abscisic acid (ABA) signaling. Subcellular localization confirmed that PuWRKY22 is a nuclear protein. Using fluorescein enzyme complementation assays, PuWRKY22 was shown to bind specifically to W-box cis-elements, indicating its function as a transcriptional regulator. Under ABA and osmotic (sorbitol) stress, the seed germination rate, root growth, and biomass of tobacco and Populus davidiana × Populus bolleana strains overexpressing PuWRKY22 were significantly increased. Additionally, these overexpressed strains exhibited a reduction in reactive oxygen species (ROS) accumulation and a decrease in membrane lipid peroxidation. Transcriptomic analyses revealed that PuWRKY22 activates expression of the ABA receptor gene Ptr.PYL4 (Potri.006G104100.v4.1), which regulates stomatal closure to minimize water loss. Consistent with this, stomatal observations and photosynthetic measurements demonstrated that PuWRKY22 enhances drought tolerance by protecting photosystem II and preserving chlorophyll content. Collectively, this study elucidates the molecular mechanism by which PuWRKY22 enhances drought resistance in woody plants through ABA signaling, providing a foundation for breeding drought-tolerant forest species. Full article

Soluble sugars, primarily fructose, glucose, sucrose, and sorbitol, are crucial determinants of fruit flavor and quality. As a core component of biological metabolism, sugar metabolism provides energy and carbon for fruit development, ultimately governing carbohydrate accumulation in mature fruits. This process requires the coordinated activities of multiple enzymes and transporters, modulated by the spatiotemporal expression patterns of their encoding genes. Therefore, it is essential to elucidate both the activities of these enzymes across different fruits and their underlying gene expression patterns. While significant progress has been made in functional genes involved in soluble sugar metabolism and deciphering their regulatory networks, an overall introduction of this knowledge remains lacking. This review presents an integrative analysis of soluble sugar accumulation during fruit development, encompassing spatiotemporal dynamics of key metabolic enzymes, functional characterization of encoding genes, signaling response mechanisms governing gene regulation, and the overarching genetic network. Full article

Peach (Prunus persica (L.)) fruits are abundant in nutrients, with fruit shape and sugar content serving as critical indicators of fruit quality. Melatonin plays a pivotal role in peach fruit development; however, the mechanisms by which it regulates fruit shape development, sugar metabolism, and secondary metabolites remain largely unknown. In this study, peach trees were sprayed with 150 µM melatonin 20 days after pollination. Traditional methods were used to investigate fruit morphology, total soluble solids (TSSs), and titratable acidity content (TAC), while liquid chromatography–mass spectrometry (LC-MS) was employed to analyze sugar metabolites during fruit development. The results indicated that melatonin treatment augmented the transverse and longitudinal diameters of peach fruits by 12% and 6%, respectively, and elevated the contents of soluble solids and titratable acid by 7% and 6%, respectively. The single fruit weight experienced a significant increase of 29.4%, whereas fruit firmness at maturity remained unchanged. Metabolite analysis demonstrated that melatonin decreased the levels of sucrose and D-sorbitol in mature fruits but enhanced the accumulation of D-fructose, L-rhamnose, and xylose. Significantly, melatonin expedited the degradation of galactose, D-mannose, and methyl-D-pyranogalactoside prior to maturity (all three substances naturally decline with fruit ripening), highlighting its role in promoting fruit ripening. In conclusion, exogenous melatonin improves the internal nutrition and flavor quality of fruit by regulating the accumulation of primary and secondary metabolites during fruit ripening. Specifically, the increase in D-fructose (a major contributor to sweetness) and L-rhamnose (a potential precursor for aroma compounds) enhances fruit flavor profile. The accelerated degradation of galactose, D-mannose, and methyl-D-pyranogalactoside (components of cell wall polysaccharides) prior to maturity, alongside the metabolic shift favoring fructose accumulation over sucrose, highlights melatonin’s role in promoting fruit ripening and softening processes. It also promotes fruit enlargement and single fruit weight without affecting fruit firmness. This study establishes a theoretical basis for the further investigation of the molecular mechanisms underlying melatonin’s role in peach fruits and for enhancing quality-focused breeding practices. Full article

Diabetic retinopathy (DR), traditionally considered a microvascular complication, is now recognized as a neuroinflammatory disorder involving retinal glial cells. Aldose reductase (AKR1B1), a key enzyme in the polyol pathway, has been implicated in the hyperglycemia-induced inflammatory response in various cell types, although its role in retinal Müller glial cells under acute glucose stress remains unclear. This study investigates AKR1B1 activity and its contribution to inflammatory signaling in MIO-M1 human Müller cells exposed to acute hyperglycemia. AKR1B1 expression and activity, as well as NF-κB activation and COX-2 expression, were evaluated. Sorbinil, a specific AKR1B1 inhibitor, was used to determine the enzyme’s contribution to acute hyperglycemia-induced inflammation. Acute high-glucose treatment significantly increased AKR1B1 activity and sorbitol accumulation without affecting cell viability. In addition, activation of NF-κB and increased expression of cyclooxygenase-2 (COX-2) were observed, both of which were significantly reduced by Sorbinil. Our findings highlight the role of macroglia as active contributors to early inflammatory events in DR and suggest that transient hyperglycemic spikes are sufficient to trigger AKR1B1-dependent glial activation. Full article

Propionic acid (PA) is an important organic acid with applications in food preservation, feed additives, and bio-based chemical production. While industrial PA is mostly derived from petrochemical processes, sustainable microbial alternatives are gaining attention. In this study, we explored a co-fermentation strategy using lactic acid bacteria (LAB) with complementary metabolic capabilities to enhance PA biosynthesis via the 1,2-propanediol (PDO) pathway. Genome-based screening identified a metabolic division between strains capable of producing PDO (e.g., Carnobacterium maltaromaticum IBB3447) and those converting PDO to PA (e.g., Levilactobacillus brevis IBB3735). Notably, we discovered that C. maltaromaticum IBB3447 is capable of PDO 24 biosynthesis, a function previously undescribed in this species. Phenotypic assays confirmed glycerol metabolism and acid tolerance among strains. In co-culture fermentation trials, the highest PA concentration (6.87 mM) was achieved using simultaneous fermentation in a fructose–sorbitol–glucose (FRC-SOR-GLC) medium, accompanied by prior PDO accumulation (up to 13.13 mM). No single strain produced PA independently, confirming that metabolic cooperation is required. These findings reveal a novel LAB-based bioprocess for sustainable PA and PDO production, using cross-feeding interactions and the valorization of industrial waste streams. The study supports future optimization and scale-up for circular bioeconomy applications. Full article

Appropriate calcium treatments help maintain the appearance, nutritional quality, and postharvest quality of apples, reducing losses during storage. This study investigated the effects of different calcium preparations on the fresh-cut quality and ultrastructure of ‘Starkrimson’ apples. The treatments included control (CK), calcium chloride (T1), sorbitol-chelated calcium (T2), and calcium nitrate (T3). The results demonstrated that sorbitol-chelated calcium significantly inhibited the decline in fresh-cut firmness and pectin content while reducing the increase in cellulose content and minimizing ultrastructural damage. Apples treated with sorbitol-chelated calcium maintained the best fresh-cut hardness and soluble pectin contents, which were 35.71% and 15.42% higher than that of CK on the 12th day, and the cellulose was 27.08% lower than that of CK. Under transmission electron microscopy, the pulp cell surface in the T2 group remained intact, with no bending or deformation, and the middle lamella was well preserved. Additionally, T2 treatment promoted the expression of aroma-related genes during fruit storage. Sorbitol-chelated calcium effectively preserved color and significantly reduced the browning and microbial spoilage of fresh-cut apples, particularly postharvest pathogen growth. The study demonstrates that sorbitol-chelated calcium preserves fresh-cut apple quality by reinforcing cell wall integrity through calcium-mediated crosslinking, suppressing pectin degradation and cellulose accumulation, and activating aroma-related genes (AAT1, AAT2, LOX) to enhance volatile synthesis, thereby reducing microbial spoilage and enzymatic browning during storage. Full article

Fungal infections are a major but often neglected global health challenge, affecting both human health and agricultural productivity. Current treatments are limited by few drug classes and increasing multidrug resistance, exacerbated by the widespread use of antifungal agents in clinical and agricultural settings. This study investigates the antifungal potential of a novel 8-hydroxyquinoline derivative with a triazole core at the 5-position, synthesized to improve both efficacy and mechanistic understanding as a fluorescent chemical probe. Biological assays demonstrated significant antifungal activity of compound 10 against a range of pathogens, which was active against all Candida species, dermatophytes, and Fusarium solani with MIC values ranging from 0.5 to 4 µg/mL. Confocal fluorescence microscopy of treated fungal cells was conducted and showed a high accumulation of compound 10 at the cell edge. To further investigate the mode of action, results from a sorbitol protection assay suggested a possible cell wall action, and scanning electron microscopy (SEM) revealed cell wall disruption, such as cell shrinkage and surface roughness, in treated fungal cells. These findings highlight the 8-hydroxyquinoline-triazole scaffold as a promising antifungal agent with cell wall damage properties, providing a basis for future therapeutic development against human and plant fungal pathogens. Full article