Abstract In this study, we focused on the key hypoglycemic oligosaccharide components derived from thinned peach crude polysaccharides (CPPS), elucidated their structural characteristics and hypoglycemic mechanisms, and improved the utilization of this agricultural waste. CPPS was fractionated via anion-exchange chromatography and ultrafiltration, yielding 2 key components (W1-2 and W2-2) with enhanced α-glucosidase inhibition and half maximal inhibitory concentration (IC50) were 0.57 and 0.37 mg/mL, respectively. They improved glucose consumption, glycogen synthesis, hexokinase, and pyruvate kinase activities in insulin resistant HepG2 cells. Structural analysis using LC-MS and methylation revealed W1-2 contains disaccharides where galactose or glucose is linked to terminal arabinose through 1,4-glycosidic bonds, alongside arabinose-rich pentasaccharides featuring T-Araf, 1,5-Araf and 1,3,5-Araf residues. W2-2 comprises trehalose-like disaccharides with accounting for 76.95% of T-Glcp and arabinose pentasaccharides with similar branching patterns. These findings suggest that trehalose-like disaccharides and arabinose-derived pentasaccharides in CPPS may play a key role in blood glucose regulation. This study offers important insights into the roles of bioactive carbohydrates in diabetes intervention.

This study applied diffusion-prepared pseudo-continuous arterial spin labeling (DP-pCASL) to quantify cerebral blood flow (CBF), arterial transit time (ATT), and blood-brain barrier (BBB) water exchange rate (Kw) before and after focused ultrasound (FUS)-mediated blood-brain barrier opening (BBBO) in the dorsal striatum of four non-human primates. Six baseline and seven BBBO sessions were performed. DP-pCASL was acquired approximately 45 min after FUS sonication combined with intravenous microbubbles, and contrast-enhanced T1-weighted imaging was subsequently used to confirm the BBBO region. Whole-brain analyses revealed no significant changes in CBF or ATT following BBBO (permutation p > 0.05). Region-of-interest analysis within the sonicated caudate demonstrated a significant localized decrease in Kw, with median (IQR) values of 45.0 (40.6 - 55.6) min⁻¹ at the BBBO site versus 61.6 (58.3 - 70.4) min⁻¹ in the contralateral control region (p < 0.05), confirming spatially specific suppression of transendothelial water flux. In contrast, whole-brain Kw increased significantly following BBBO, with median (IQR) values of 49.8 (46.3 - 55.9) min⁻¹ in non-BBBO sessions versus 59.4 (56.6 - 66.3) min⁻¹ in BBBO sessions (p < 0.01), indicating a diffuse enhancement of water exchange across the brain. These findings establish DP-pCASL-derived Kw as a sensitive, non-contrast biomarker for both local and global BBB permeability changes induced by focused ultrasound, supporting its potential for longitudinal monitoring in preclinical and clinical neurotherapeutic applications.

A large amount of fruit is wasted each year due to postharvest physiological metabolism (e.g., respiration and transpiration and ripening), improper storage conditions (e.g., gas environment, temperature, and humidity), and deterioration triggered by microbial multiplication, of which tissue browning is particularly serious. Although a large number of experiments have been conducted focusing on one or more factors affecting enzymatic browning in postharvest fruit, there are few systematic and comprehensive summaries of those core factors that influence fruit browning during postharvest storage. Therefore, this paper comprehensively summarizes the key factors, including cell membrane integrity, browning-related enzymes, associated enzyme substrates, and reactive oxygen species (ROS) as well as how they influence fruit browning after harvest under different conditions. Based on the synergistic interaction of multiple factors, membrane structural disruption induced by important postharvest factors serves as the primary prerequisite for enzymatic browning, while ROS act as key signaling molecules that intensify the process. Under such conditions, enzyme catalyzed-browning reactions become inevitable, but the degree of browning is significantly regulated by various postharvest treatments. Furthermore, how different fruit varieties and ripening stages respond to these core factors is also significantly varied. Future research should focus on elucidating the synergistic regulatory mechanisms governing enzymatic browning influenced by these factors, especially carefully considering the variations among different fruit types and ripening stages. Furthermore, the necessity of using combined technologies targeting these core factors is emphasized for inhibiting postharvest fruit browning.

Background Subtle blood-brain barrier (BBB) leakage has been detected in small vessel disease (SVD). While established methods rely on gadolinium-based contrast agents (GBCA), diffusion-weighted arterial spin labelling (DW-ASL) is a promising alternative which assesses water exchange rate (kw) without injected contrast. However, DW-ASL has not been widely applied in sporadic SVD. We aimed to determine how kw varied with GBCA BBB leakage measures, baseline and 1-year change in SVD burden. Methods We recruited patients with mild ischaemic stroke (lacunar or cortical) all characterised for SVD features. We assessed kw using DW-ASL and GBCA measures of BBB leakage (permeability-surface area product (PS), blood plasma volume and exchange rate of GBCA) using dynamic-contrast enhanced MRI. We used separate linear regression models to assess how kw varied with GBCA-derived metrics, baseline and 1-year change in WMH volume in co-variate-adjusted analyses. Results We included 24 with complete MRI (61±10 years; 71% male). Patients with higher kw tended to have more severe baseline SVD (e.g. subcortical grey matter (SGM): B=14.59 min-1/%WMH volume, 95% confidence interval (95%CI)=-1.00,28.18, p=0.04) and greater 1-year increase (B=0.0013 %WMH volume increase/min-1, 95%CI=-0.0001, 0.0026, p=0.06). We generally found kw and GBCA BBB leakage measures were not meaningfully associated (e.g. SGM kw∼PS: B=-0.23 min-1/10-4min-1, 95%CI=-7.47, 7.01, p=0.95). Conclusion BBB water exchange estimated using DW-ASL tended to be greater with higher WMH burden and progression, suggesting kw may be a sensitive measure of BBB dysfunction in SVD. However, non-concordance between kw and GBCA metrics suggests the two methods probe different aspects of BBB function.

Owing to their high-water contents, low calorie density, easy-to-swallowing properties, polysaccharide gels have attracted increasing attention in the food industry and almost exist in our every day’s life. Gelation is one of the most important properties for polysaccharides, which describes a process of chain-chain aggregation and the formation of a three-dimensional network structure that finally leads to a drastic change in the macroscopic mechanical properties, i.e., from a solution with good fluidity to a gel with self-supporting property. Moreover, the gelation process is also considered to cause remarkable changes in the microenvironments in the interspatial network and in the polymer chain’s mobility as well as the polymer-water interactions. Therefore, it is important to have a fundamental understanding of how polysaccharides form gels from macroscopic, microscopic to molecular levels. In this review article, we have summarized the application of bulk rheology, particle tracking, light scattering, nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and some other tools in elucidating the network structures and gelation mechanism of typical gelling polysaccharides gellan and carrageenans. It has been demonstrated that these techniques are powerful to provide important information on the gelation mechanism and network structure at different length scales.

Purpose:To develop an accelerated motion-compensated diffusion-weighted pseudo-continuous arterial spin labeling (MCDW-pCASL) method using a spatial subspace low-rank reconstruction method for efficient quantification of blood-brain barrier (BBB) water exchange (kw) and permeability (PSw). Methods:An accelerated multidelay MCDW-pCASL sequence was developed to simultaneously encode intravascular and extravascular diffusion-weighted ASL signals across multiple post-labeling delays (PLDs). A spatial subspace low-rank reconstruction framework was optimized to enable joint estimation of cerebral blood flow (CBF) and BBB water exchange rate and permeability. Fourteen young healthy adults underwent test-retest scans (separated by ~1 week) at 3T with both the accelerated MCDW-pCASL and a conventional diffusion-prepared (DP) pCASL sequence. Whole-brain, gray-matter, and white-matter CBF and kw values were quantified to assess test-retest repeatability and cross-method agreement. An additional cohort of 30 older adults underwent single-session MCDW and DP scans to evaluate age-related perfusion and BBB kw/PSw differences. Intraclass correlation coefficients (ICCs) were used to assess reliability and agreement. Results:Accelerated MCDW-pCASL demonstrated excellent agreement with DP-pCASL for CBF (ICC = 0.89) and fair agreement for kw (ICC = 0.56). Test-retest repeatability of MCDW-pCASL was good for CBF, BBB kw and PSw (ICC ≈ 0.6). Across both sequences, younger subjects exhibited significantly higher CBF and kw compared with older adults. Conclusion:Incorporating a spatial low-rank subspace reconstruction enables accelerated MCDW-pCASL acquisition with reliable simultaneous quantification of CBF, BBB kw and PSw. Clinical applications of this method for assessing perfusion and BBB function are warranted.

Peach is highly susceptible to postharvest brown rot caused by Monilinia fructicola. In this study, treatment with 0.15 mM sodium hydrosulfide (NaHS), a hydrogen sulfide (H2S) donor, reduced lesion diameter and disease incidence compared with the control. Mechanistically, NaHS enhanced host defense by upregulating pathogenesis-related (PR) genes, including PpPR1 and PpPR5, as well as PpGNS and PpCHI, which encode beta-1,3glucanase (GNS) and chitinase (CHI), respectively. NaHS also promoted phenylpropanoid metabolism by increasing the transcript levels and activities of phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate:CoA ligase (4CL), together with the accumulation of phenolics and flavonoids. In parallel, NaHS enhanced reactive oxygen species (ROS)-scavenging enzyme activities and reduced H2O2 accumulation. In vitro, NaHS directly increased the activities of phenylpropanoid enzymes in a dose-dependent manner. Overall, low-dose NaHS improved postharvest resistance through multi-layered defense involving PR proteins, phenylpropanoid metabolism, and ROS homeostasis. These results support H2S-based strategies for postharvest disease management and highlight the need for careful dose optimization.

The polygalacturonase -inhibiting protein (PGIP) family member PpPGIP1 in peaches responds to Monilinia fructicola infection and positively regulates disease resistance. However, the molecular mechanism still needs to be further explored. In this study, we identified PpWRKY53, a member of the pathogen resistance-associated WRKY family. Its expression was upregulated in response to both M. fructicola infection and agaro-oligosaccharides treatment. Pearson correlation analysis indicated that PpWRKY53 and PpPGIP1 had a positive correlation. Subcellular localization analysis showed that PpWRKY53 is a nuclear localization protein. Yeast one-hybrid and electrophoretic mobility shift assays demonstrated that PpWRKY53 bound directly to the W-box element within the PpPGIP1 promoter. The dual-luciferase reporter system further revealed that PpWRKY53 positively activated PpPGIP1 expression. Furthermore, transient overexpression of PpWRKY53 in peach fruit upregulated the expression of PpPGIP1, while silencing PpWRKY53 downregulated the expression of PpPGIP1. In summary, PpWRKY53 transcriptionally activating PpPGIP1 contributes to agaro-oligosaccharides-induced disease resistance in peach fruit.

The gelation process of two deacetylated gellan (DG) fractions with different molecular weights (DG-1: Mw approximate to 671 kDa, DG-2: Mw approximate to 504 kDa) was studied at a fixed DG concentration (1.0 %, w/w) and varying sucrose concentrations (0-60 %, w/w). Rheological measurement suggested that sucrose addition promoted the gelation temperature (Tgel) of DG-1 in a concentration-dependent manner, with the Tgel shifting from 28, 31, 40-44 degrees C in 0, 20, 40 and 60 % sucrose solutions, respectively. This result is well consistent with the data of particle tracking experiment, where the ensemble mean square displacements (MSD) of the probe particles (1.0 mu m) steeply decreased around the Tgel for each sucrose DG-1 solution, reflecting a diffusional confinement by forming gel network. Micro-DSC data suggested that the ordered structure formation temperature (Torder) of DG-1 was also enhanced by sucrose addition, with Torder approximate to 28, 31, 37 degrees C for 0, 20, 40 % sucrose addition, respectively. However, at 60 % sucrose concentration, no exothermic peak was observed, possibly indicating that high concentration sucrose induced a DG network structure crosslinked by intermolecular point-to-point hydrogen bonding. Moreover, 1H NMR measurement suggested the molecular mobility of DG chains significantly decreased around the Tgel for each sucrose DG-1 solution. However, at 60 % sucrose concentration, the NMR spectrum of DG-1 became much less detectable, possibly due to a high solution viscosity that significantly decreased DG chain mobility. Compared with DG-1, DG-2 displayed a gelation behavior similar to that of DG-1, but with a slightly weaker gelling ability due to smaller Mw.

The marine antagonistic yeast Scheffersomyces spartinae W9 can significantly control gray mold in strawberries caused by Botrytis cinerea. 2-Phenylethanol (2-PE), a quorum sensing molecule, is also a volatile organic compound secreted by S. spartinae W9. Herein, we investigated the role of 2-PE in regulating the population density and biocontrol efficacy of S. spartinae W9. The results showed that 2-PE significantly increased the population density and biofilm formation ability of S. spartinae W9, and further enhanced its stress tolerance. 2-PE significantly enhanced the ability of S. spartinae W9 to inhibit the mycelial growth and spore germination of B. cinerea, and also improved its biocontrol efficacy and colonization ability against gray mold on strawberries. Further analysis of the associated regulatory genes revealed that 2-PE significantly upregulated the expression of 2-PE biosynthesis-related genes including ARO8, ARO9, and ARO10, cell proliferation-related genes including CDC25, RNR2, and TDH1, biofilm formation-related genes including FLO8, ECM4_1, and ERG3, as well as stress tolerance-related genes GRE2_4, CYS3, and AOX2. These results provide a more comprehensive molecular explanation of how 2-PE acts as a quorum-sensing molecule to improve the population density and biocontrol efficacy of S. spartinae W9.

The Monilinia fructicola is the most common pathogen causing brown rot in postharvest peach fruit. Research on green prevention and control strategies for diseases of postharvest peaches is extremely urgent. Fucoidan (FUC), a marine-derived polysaccharide, has demonstrated promising biological activities, yet the study on its application in managing diseases in postharvest fruits and vegetables has rarely been reported. This study investigated the inhibitory effects and underlying mechanisms of FUC on brown rot in postharvest peach fruit. The results revealed that FUC (6 g/L) treatment prominently enhanced disease resistance by inducing host defense responses. FUC induced the enhancement of pathogenesis-related proteins (chitinase, beta-1,3-glucanase) and significantly heightened the activities of key enzymes in phenylpropanoid pathway (phenylalanine ammonialyase, cinnamate 4-hydroxylase, 4-coumarate coenzyme A ligase, peroxidase). Concurrently, a noteworthy accumulation of lignin was observed. Moreover, jasmonic acid (JA) content prominently increased. Associated with a known transcriptional network, the results demonstrated that FUC upregulated PpMYC2 expression, thereby activating critical lignin biosynthesis genes (PpPAL1, PpC4H, Pp4CL1, PpCSE, and PpCCoAOMT1) and ultimately enhancing host disease resistance. Collectively, this study illustrated that FUC functions as a potent resistance inducer, dramatically enhancing the disease resistance of postharvest peaches primarily by activating lignin biosynthesis.

Trypsin (Try) has been reported to possess specific superoxide anion-scavenging activity and to exert pronounced anti-senescence effects in Hylocereus undatus fruit; however, the mechanisms underlying its anti-senescence function remain unclear. This study identified TAP4 as the most bioactive peptide among Try autolysis peptides (TAPs). Single-cell transcriptomic analysis revealed that TAP4 alters pericarp cell differentiation trajectories during senescence, particularly in endocarp (EN) cells. It activates the transcription factor (TF) HuWRKY21-1, specifically inducing immune responses in inner pericarp cells and upregulating 44 immune-related genes, including HuIGP4 and HuLYK6. Downstream factors, such as HuFULL and ethylene response factors (ERFs), promote the biosynthesis of antioxidants, such as antheraxanthin and hyperin. Functional validation via virus-induced gene silencing (VIGS), callose deposition, disease resistance assays, and quantitative reverse-transcription PCR confirmed the roles of key TFs, including HuWRKY21-1, HuFULL, and HuERF30-1, in immune activation and resistance reconstruction. This work provides evidence for the potential of the EN as a defensive tissue in fruit and opens new avenues for understanding the mechanisms underlying the establishment of plant resistance.

Radish sprouts, which are nutritious microgreen vegetables, exhibit diverse colors and flavors. To elucidate the molecular mechanisms underlying these quality traits, we performed integrated transcriptomic and metabolomic analyses. Comparative studies across green, red, and purple radish sprouts identified 31 key genes regulating flavonoid accumulation, with RsPAL, Rs4CL, and others significantly upregulated in purple sprouts, followed by red sprouts. Specifically, the peak expression of RsFLS genes in red radish sprouts may lead to an elevated accumulation of kaempferol derivatives and a bitter taste. Additionally, 12 genes, including RsCYSD1 and RsOASC, were linked to glucosinolate accumulation with higher expression in red varieties. Consistently, higher aliphatic GSLs (5-oxoheptyl glucosinolate) and indole GSLs (indolylmethyl desulfoglucosinolate) were identified in red radish sprouts. The high myrosinase activity may lead to sulforane accumulation and pungent and sulfurous flavor in purple radish sprouts. These findings provide comprehensive insights into the genetic and metabolic bases of radish sprout coloration and taste formation.

Postharvest water loss significantly affects fruit storability. Hydrogen sulfide (H₂S) is an emerging gaseous signaling molecule with demonstrated preservation potential for harvested fruit; however, the mechanism by which it controls postharvest water loss needs further investigation. In this study, NaHS (9 mmol·L⁻¹) was applied to peach fruit (Prunus persica (L.) Batsch cv. 'Hujing') to investigate changes in cuticular wax at 5 d after treatment, as well as pectin degradation and cell wall characteristics during storage. NaHS treatment increased total cuticular wax content from 21.30 ± 2.64 μg·cm⁻² to 28.07 ± 1.20 μg·cm⁻² and alkane content from 9.51 ± 1.01 μg·cm⁻² to 11.43 ± 0.41 μg·cm⁻² at 5 days after treatment, resulting in a more continuous and compact wax layer on the fruit surface. Also, NaHS treatment suppressed pectin-degrading enzyme activities, with the strongest reduction in polygalacturonase activity observed at 1 d after treatment (74.0%) and a significant reduction in pectin methylesterase activity already evident at 0 d after treatment (31.5%), and slowed the conversion of sodium carbonate-soluble and chelator-soluble pectins into water-soluble pectin. Together, these results indicate that NaHS treatment alleviates postharvest water loss in peaches by enhancing epidermal wax accumulation and delaying cell wall degradation. These findings offer new insights into the physiological role of H₂S in postharvest fruit preservation.

MYC2 transcription factor has been extensively investigated in plant stress responses. However, its role in regulating fruit cold tolerance remains largely unexplored. In this study, exposure to cold stress rapidly activated the transcription of PpMYC2 in peach fruit. DNA affinity purification sequencing (DAP-seq) data revealed that PpMYC2 showed high affinity for the promoter region of PpVIN2 - a key gene encoding acidic vacuolar invertase (VIN) critical for sucrose catabolism in peach fruit. Yeast one-hybridization (Y1H), electrophoretic mobility shift assay (EMSA) and dual-luciferase reporter (DLR) assay collectively revealed that PpMYC2 directly bound to the G-box cis-element in the PpVIN2 promoter and significantly suppressed its promoter activity. Transient overexpression of PpMYC2 in peach fruit resulted in downregulated transcription of PpVIN2, reduced VIN activity, and increased sucrose content, whereas opposite changes were detected in peach fruit with transient silencing of PpMYC2. Additionally, we generated tomato plants stably overexpressing PpMYC2 using Agrobacterium-mediated transformation, and observed that PpMYC2-overexpressing tomato fruit exhibited significantly enhanced cold tolerance, accompanied by the inhibition of sucrose degradation. Collectively, these discoveries indicate that PpMYC2 acts as a transcriptional repressor of PpVIN2 under cold stress, thereby reducing sucrose breakdown and enhancing peach fruit chilling tolerance. This study identifies PpMYC2 as a potential molecular target for alleviating chilling injury in peach fruit.

Strawberry (Fragaria × ananassa) is highly susceptible to gray mold caused by Botrytis cinerea. WRKY transcription factors and jasmonic acid (JA) are central to defense against necrotrophs, yet the regulatory interaction in strawberry remains unclear. Here, we characterized FaWRKY21, a terpinen-4-ol-responsive, Group IIc WRKY gene encoding a nuclear-localized protein. Transient overexpression in strawberry fruit enhanced defense against B. cinerea and increased endogenous JA concentrations. This enhanced defense was confirmed in transgenic Arabidopsis plants overexpressing FaWRKY21, where AtPDF1.2 and other defense markers were upregulated. Transcriptomic and qRT-PCR analyses revealed that FaWRKY21 upregulates JA biosynthetic genes, notably FaOPR3II, FaJMT, and FaAOS-C. Yeast one-hybrid, EMSA, and dual-luciferase assays demonstrated direct binding to W-box elements in their promoters and transcriptional activation. Our findings establish FaWRKY21 as a direct activator of JA biosynthesis that positively regulates defense against B. cinerea, offering molecular targets for developing elicitor-based strategies to control postharvest gray mold.

This study investigated the effects of onion aqueous extract treatment on nutrient retention in fresh-cut potatoes during storage as well as the flavor profiles after subsequent cooking. The results showed that the onion aqueous extract significantly slowed the loss of ascorbic acid and increased the contents of gamma-aminobutyric acid (GABA), total phenols, and flavonoids in fresh-cut potatoes during storage. Sensory evaluation showed the deep-fried onion aqueous extract-pretreated potatoes received higher scores in aroma, taste, and color compared to untreated potatoes. The electronic nose analysis indicates that the deep-frying processing significantly enhanced the overall flavor intensity, whereas the stir-frying processing better distinguished flavor differences between treatments and more reflected the intrinsic flavor of the potatoes. Therefore, the stir-fried group was selected for further analysis. GC-IMS analysis further demonstrated that onion aqueous extract elevated key volatile compounds in cooked potatoes, including ketones such as 1-octen-3-one contributing a distinct vegetable aroma, while aldehydes and sulfides added pungent, and wine-like flavor. Overall, these findings propose an eco-friendly preservation method that not only maintains nutritional quality in fresh-cut potatoes but also enhances their sensory attributes after cooking, offering a dual-purpose strategy for quality improvement in freshcut potatoes processing and subsequent cooking.

PURPOSE:To achieve high resolution (≤ 1 mm isotropic) whole-brain perfusion imaging at 7 T with next generation ASL pulse sequence, reconstruction algorithm, and MRI hardware. METHODS:We capitalized on three major innovations: (1) FLASH-based pseudo-Continuous ASL (pCASL) sequence with rotated golden-angle stack-of-spirals (rGA-SoS) sampling; (2) dynamic compressed sensing (CS) reconstruction with high spatiotemporal resolution and motion-resolved self-navigation; and (3) high density array coil and high-performance Impulse gradient of the NexGen 7 T scanner. Whole-brain laminar perfusion imaging was validated by correlation with histological data of microvascular and cell body density, as well as through finger-tapping (FT) and working memory (WM) fMRI tasks. RESULTS:The proposed rGA-SoS sequence achieved a 3.3-fold SNR and 2-fold higher intraclass correlation coefficient (ICC) compared to matched Cartesian sampling at 7 T, enabling up to 0.8 mm isotropic spatial resolution and/or a temporal resolution of 14 s at 1 mm isotropic. Resting-state perfusion showed strong correlations with microvascular and cell body density. Laminar perfusion fMRI revealed a two-peak activation in the primary motor cortex induced by FT, and distinct laminar profiles for task-positive and task-negative networks during WM task. CONCLUSION:This method offers a noninvasive imaging tool to bridge the gap between mesoscopic MRI with microscopic cellular imaging, as well as to investigate neural excitation and inhibition underlying positive and negative fMRI activations.