Integrative Metabolomic and Transcriptomic Landscape during Akebia trifoliata Fruit Ripening and Cracking.

Akebia trifoliata fruit is prone to crack after ripening, but little is known about the mechanism underlying the cracking process. This study integrated transcriptomic and metabolomic data, revealing significant changes in 398 metabolites and 8414 genes during ripening and cracking, mainly impacting cell-wall metabolism. Multi-omics joint analysis indicated that genes related to polygalacturonase, pectate lyase, α-amylase, and glycogen phosphorylase were up-regulated after cracking, degrading cell wall and starch. Concurrently, diminished photosynthetic metabolism and heightened phenylpropanoid metabolism suggested alterations in cuticle structure, potentially impacting cell-wall robustness. Numerous auxin and abscisic acid signaling-related genes were expressed, and we assume that they contributed to the promoting peel growth. These alterations collectively might compromise peel strength and elevate expanding pressure, potentially leading to A. trifoliata cracking. Transcription factors, predominantly ethylene response factors and helix-loop-helix family members, appeared to regulate these metabolic shifts. These findings provide valuable insights into A. trifoliata cracking mechanisms; however, direct experimental validation of these assumptions is necessary to strengthen these conclusions and expedite their commercial utilization.

Effects of antiepileptic drugs polytherapy on pregnancy outcomes in women with epilepsy: An observation study in northwest China.

OBJECTIVE: The management of pregnant women with epilepsy (WWE) treated with antiepileptic drugs (AEDs) polytherapy poses a great challenge. The purpose of this study was to evaluate the major congenital malformations (MCMs) associated with AED polytherapy, to assess the impacts of polytherapy regimens on seizure control and breastfeeding, and to determine the potential predictors for pregnancy outcomes. METHODS: This study was based on prospectively acquired data from a registry enrolling WWE in early pregnancy from Feb 2010 to July 2019, in which 123 pregnancies in 110 WWE were exposed to 27 different AED combinations. RESULTS: There were 123 pregnancies in 110 WWE analyzed in our study. The live birth rate was 86.2 % and the risk of MCMs was 10.4 %. Multivariate analysis indicated that prenatal exposure to phenobarbital (odds ratio [OR], 17.424; 95 %CI, 1.510-201.067; P = 0.022) and topiramate (OR, 9.469; 95 %CI, 1.149-62.402; P = 0.036) was associated with increased risk of MCMs. Valproate (OR, 4.441; 95 %CI, 1.165-16.934; P = 0.029), phenobarbital (OR, 13.636; 95 %CI, 2.146-86.660; P = 0.006) and topiramate (OR, 7.527; 95 %CI, 1.764-32.118; P = 0.006) were significantly correlated with adverse pregnancy outcomes. Among 67 pregnancies in four combinations over 10 patients, 15 (22.4 %) remained seizure free through pregnancy, seizure frequency increased in 17 (25.4 %), decreased in 24 (35.8 %) women, in 26 (38.8 %) remained unchanged. Only 23.6 % of mothers undertook exclusive breastfeeding. Planned pregnancy was the only independent factor significantly associated with decreased risk of adverse pregnancy outcomes (OR, 0.139; 95 % CI, 0.051-0.382; P < 0.001). Notably, no adverse pregnancy outcome was recorded in pregnancies exposed to the combination of lamotrigine plus levetiracetam. CONCLUSION: Prenatal exposure to the combinations containing valproate, phenobarbital, or topiramate was associated with increased risk of adverse pregnant outcomes. AED-related teratogenicity may be reduced by planned pregnancy in WWE exposed to polytherapy. Our findings also suggest the combination of lamotrigine and levetiracetam seems to be most desirable to balance seizure control and fetal safety.

Low serum apelin levels are associated with mild cognitive impairment in Type 2 diabetic patients.

BACKGROUND: Apelin is a new adipokine that is secreted by adipocytes, and is associated with insulin resistance (IR), inflammation, and obesity. This study was designed to investigate the role of apelin in type 2 diabetes mellitus (T2DM) patients with mild cognitive impairment (MCI). METHODS: A total of 235 patients with T2DM were included. The cognitive function of patients was evaluated using Montreal Cognitive Assessment (MoCA) tool, then patients were divided into MCI group and non-MCI group according to the MoCA score. Blood sample was analyzed for the level of apelin by enzyme-linked immunosorbent assay (ELISA). RESULTS: The MCI group (n = 73) presented lower serum apelin levels compared with the patients with normal cognitive function (P < 0.001). Apelin levels showed significantly negative correlation with diabetes duration, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C, creatinine and high sensitivity C-reactive protein (hs-CRP), and positive correlation with high-density lipoprotein cholesterol (HDL-C) and brain-derived neurotrophic factor (BDNF). Multivariable logistic regression analysis indicated that serum apelin (OR = 0.304, 95%CI: 0.104-0.886, P = 0.029), as well as education levels, diabetes duration, cardiovascular disease, serum HbA1c, HDL-C, creatinine, and BDNF, were independent risk factors of MCI in patients with T2DM. CONCLUSIONS: Serum apelin level is reduced in T2DM patients with MCI. Apelin might has protective effect against cognitive impairment and serve as a serum biomarker of T2DM.

Tanshinone IIA improves contextual fear- and anxiety-like behaviors in mice via the CREB/BDNF/TrkB signaling pathway.

Posttraumatic stress disorder (PTSD) is one of the most common psychiatric diseases, which is characterized by the typical symptoms such as re-experience, avoidance, and hyperarousal. However, there are few drugs for PTSD treatment. In this study, conditioned fear and single-prolonged stress were employed to establish PTSD mouse model, and we investigated the effects of Tanshinone IIA (TanIIA), a natural product isolated from traditional Chinese herbal Salvia miltiorrhiza, as well as the underlying mechanisms in mice. The results showed that the double stress exposure induced obvious PTSD-like symptoms, and TanIIA administration significantly decreased freezing time in contextual fear test and relieved anxiety-like behavior in open field and elevated plus maze tests. Moreover, TanIIA increased the spine density and upregulated synaptic plasticity-related proteins as well as activated CREB/BDNF/TrkB signaling pathway in the hippocampus. Blockage of CREB remarkably abolished the effects of TanIIA in PTSD model mice and reversed the upregulations of p-CREB, BDNF, TrkB, and synaptic plasticity-related protein induced by TanIIA. The molecular docking simulation indicated that TanIIA could interact with the CREB-binding protein. These findings indicate that TanIIA ameliorates PTSD-like behaviors in mice by activating the CREB/BDNF/TrkB pathway, which provides a basis for PTSD treatment.

Hydrogen Alleviates Necroptosis and Cognitive Deficits in Lithium-Pilocarpine Model of Status Epilepticus.

Status epilepticus without prompt seizure control always leads to neuronal death and long-term cognitive deficits, but effective intervention is still absent. Here, we found that hydrogen could alleviate the hippocampus-dependent spatial learning and memory deficit in lithium-pilocarpine model of status epilepticus in rats, as evidenced by the results in Morris water maze test. Hydrogen treatment downregulated the expression of necroptosis-related proteins, such as MLKL, phosphorylated-MLKL, and RIPK3 in hippocampus, and further protected neurons and astrocytes from necroptosis which was here first verified to occur in status epilepticus. Hydrogen also protected cells from apoptosis, which was indicated by the decreased cleaved-Caspase 3 expression. Meanwhile, Iba1+ microglial activation by status epilepticus was reduced by hydrogen treatment. These findings confirm the utility of hydrogen treatment in averting cell death including necroptosis and alleviating cognitive deficits caused by status epilepticus. Therefore, hydrogen may provide a potential and powerful clinical treatment for status epilepticus-related cognitive deficits.

Early Predictors of Drug-Resistant Epilepsy Development after Convulsive Status Epilepticus.

BACKGROUND: Drug-resistant epilepsy (DRE) is a common and serious consequence of convulsive status epilepticus (CSE). Little is known on the early prediction of DRE development after CSE. Our aim was to identify independent DRE predictors in patients with CSE. METHODS: One hundred and forty consecutive patients identified with CSE in a tertiary academic hospital between March 2008 and January 2015 were reviewed. Demographics, clinical features, serum albumin neuroimaging, and electroencephalogram characteristics were collected and analyzed. Independent predictors of DRE were identified using multivariate logistic regression. The receiver operating characteristic (ROC) curve was used to quantify the predictive validity of all the risk factors. RESULTS: After a median 62-month observation period, 91 patients were enrolled into this study. Thirty-seven (40.7%) patients did not have DRE, 22 (24.2%) developed DRE, and 32 (35.2%) were dead. History of epilepsy (OR 9.17, 95% CI 1.77-49.22, p = 0.010), status epilepticus duration ≥24 h (OR 4.82, 95% CI 1.04-22.37, p = 0.044), and cortical or hippocampal abnormalities on neuroimaging (OR 9.49, 95% CI 1.90-47.50, p = 0.006) were independent predictors of DRE after CSE. A combination of these 3 variables yielded an area under the ROC curve of 0.77 (0.65-0.89). CONCLUSIONS: History of epilepsy, longer SE duration, and cortical or hippocampal abnormalities on neuroimaging are early predictors for the development of DRE after CSE. Further studies are needed to assess whether a more aggressive treatment will reduce the likelihood of DRE development in these high-risk patients.

Diagnostic Accuracy of Cerebrospinal Fluid Procalcitonin in Bacterial Meningitis Patients with Empiric Antibiotic Pretreatment.

Accurate diagnosis of bacterial meningitis (BM) relies on cerebrospinal fluid (CSF) Gram staining and bacterial culture, which often present high false-negative rates because of antibiotic abuse. Thus, a novel and reliable diagnostic biomarker is required. Procalcitonin (PCT) has been well demonstrated to be specifically produced from peripheral tissues by bacterial infection, which makes it a potential diagnostic biomarker candidate. Here, we performed a prospective clinical study comprising a total of 143 patients to investigate the diagnostic value of CSF PCT, serum PCT, and other conventional biomarkers for BM. Patients were assigned to the BM (n = 49), tuberculous meningitis (TBM) (n = 25), viral meningitis/encephalitis (VM/E) (n = 34), autoimmune encephalitis (AIE) (n = 15), or noninflammatory nervous system diseases (NINSD) group (n = 20). Empirical antibiotic pretreatment was not an exclusion criterion. Our results show that the CSF PCT level was significantly (P < 0.01) higher in patients with BM (median, 0.22 ng/ml; range, 0.13 to 0.54 ng/ml) than in those with TBM (median, 0.12 ng/ml; range, 0.07 to 0.16 ng/ml), VM/E (median, 0.09 ng/ml; range, 0.07 to 0.11 ng/ml), AIE (median, 0.06 ng/ml; range, 0.05 to 0.10 ng/ml), or NINSD (median, 0.07 ng/ml; range, 0.06 to 0.08 ng/ml). Among the assessed biomarkers, CSF PCT exhibited the largest area under the receiver operating characteristic curve (0.881; 95% confidence interval, 0.810 to 0.932; cutoff value, 0.15 ng/ml; sensitivity, 69.39%; specificity, 91.49%). Our study sheds light upon the diagnostic dilemma of BM due to antibiotic abuse. (This study has been registered at ClinicalTrials.gov under registration no. NCT02278016.).

Enhancing Fresh-Cut Apple Preservation: Impact of Slightly Acidic Electrolyzed Water and Chitosan-Apple Essence Microencapsulation Coating on Browning and Flavor.

Fresh-cut apple preservation is a critical concern in the food industry due to the rapid deterioration of texture, color, and flavor. While our previous study introduced apple essence microencapsulation (AEM) to enhance flavor during storage, its impact on overall storage quality was minimal. Thus, this study explores the application of two preservation techniques, namely, slightly acidic electrolyzed water (SAEW) and chitosan-apple essence microencapsulation (CH-AEM) coating, to enhance the quality of fresh-cut apples. Our findings reveal that SAEW treatment significantly reduces the browning index (from 65.38 to 57.36) and respiratory rate (from 5.10% to 4.30% of CO2), and maintains a desirable aroma profile compared to uncoated treatment during 10 days of storage. Additionally, the CH-AEM coating acts as a protective barrier, further preserving the sensory characteristics of fresh-cut apples. Notably, the SAEW-CH-AEM group exhibits superior performance in firmness (8.14 N), respiratory rate (3.37% of CO2), ion leakage (34.86%), and juice yield (47.52%) after 10 days. Our research highlights the synergistic effect of combining these preservation strategies, providing a promising approach for extending the shelf life of fresh-cut apples while maintaining their visual appeal and aromatic quality. These results offer valuable insights for the fresh-cut produce industry, contributing to improved apple product preservation and consumer satisfaction.

Inactivation mechanisms on pectin methylesterase by high pressure processing combined with its recombinant inhibitor.

High pressure processing (HPP) juice often experiences cloud loss during storage, caused by the activity of pectin methylesterase (PME). The combination of HPP with natural pectin methylesterase inhibitor (PMEI) could improve juice stability. However, extracting natural PMEI is challenging. Gene recombination technology offers a solution by efficiently expressing recombinant PMEI from Escherichia coli and Pichia pastoris. Experimental and molecular dynamics simulation were conducted to investigate changes in activity, structure, and interaction of PME and recombinant PMEI during HPP. The results showed PME retained high residual activity, while PMEI demonstrated superior pressure resistance. Under HPP, PMEI's structure remained stable, while the N-terminus of PME's α-helix became unstable. Additionally, the helix at the junction with the PME/PMEI complex changed, thereby affecting its binding. Furthermore, PMEI competed with pectin for active sites on PME, elucidating. The potential mechanism of PME inactivation through the synergistic effects of HPP and PMEI.

Mice harboring the T316N variant in the GABAAR γ2 subunit exhibit sleep-related hypermotor epilepsy phenotypes and hypersynchronization in the thalamocortical pathway.

OBJECTIVE: Sleep-related hypermotor epilepsy (SHE) is a focal epilepsy syndrome characterized by seizures that predominantly occur during sleep. The pathogenesis of these seizures remains unclear. We previously detected rare variants in GABRG2, which encodes the γ2 subunit of γ-aminobutyric acid type A receptor (GABAAR), in patients with SHE and demonstrated that these variants impaired GABAAR function in vitro. However, the mechanisms by which GABRG2 variants contribute to seizure attacks during sleep remain unclear. METHODS: In this study, we designed a knock-in (KI) mouse expressing the mouse Gabrg2 T316N variant, corresponding to human GABRG2 T317N variant, using CRISPR/Cas9. Continuous video-electroencephalogram monitoring and in vivo multichannel electrophysiological recordings were performed to explore seizure susceptibility to pentylenetetrazol (PTZ), alterations in the sleep-wake cycle, spontaneous seizure patterns, and synchronized activity in the motor thalamic nuclei (MoTN) and secondary motor cortex (M2). Circadian variations in the expression of total, membrane-bound, and synaptic GABAAR subunits were also investigated. RESULTS: No obvious changes in gross morphology were detected in Gabrg2T316N/+ mice compared to their wild-type (Gabrg2+/+) littermates. Gabrg2T316N/+ mice share key phenotypes with patients, including sleep fragmentation and spontaneous seizures during sleep. Gabrg2T316N/+ mice showed increased susceptibility to PTZ-induced seizures and higher mortality after seizures. Synchronization of the local field potentials between the MoTN and M2 was abnormally enhanced in Gabrg2T316N/+ mice during light phase, when sleep dominates, accompanied by increased local activities in the MoTN and M2. Interestingly, in Gabrg2+/+ mice, GABAAR γ2 subunits showed a circadian increase on the neuronal membrane and synaptosomes in the transition from dark phase to light phase, which was absent in Gabrg2T316N/+ mice. CONCLUSION: We generated a new SHE mouse model and provided in vivo evidence that rare variants of GABRG2 contribute to seizure attacks during sleep in SHE.

TOM40 mediates the effect of TSPO on postpartum depression partially through regulating calcium homeostasis in microglia.

AIMS: To assess the effect of the translocator protein 18 kDa (TSPO) on postpartum depression and explore its mechanism. METHODS: Postpartum depression (PPD) mouse model was established, and flow cytometry, immunofluorescence, Western blot analysis, real-time quantitative PCR, adeno-associated virus (AAV), co-immunoprecipitation-mass spectrometry and immunofluorescence co-staining were used to detect the effect of TSPO ligand ZBD-2 on PPD mice. RESULTS: ZBD-2 inhibits the overactivation of microglia in the hippocampus and amygdala of PPD model mice. ZBD-2 not only inhibited the inflammation but also repressed the burst of reactive oxygen species (ROS) and mitochondrial ROS (mtROS). Meanwhile, ZBD-2 protects mitochondria from LPS-induced damages through inhibiting the influx of calcium. ZBD-2 modulated the calcium influx by increasing the level of translocase of the outer mitochondrial membrane 40 (TOM40) and reducing the interaction of TSPO and TOM40. In addition, the effect of ZBD-2 was partially dependent on anti-oxidative process. Knockdown of TOM40 by adeno-associated virus (AAV) in the hippocampus or amygdala dramatically reduced the effect of ZBD-2 on PPD, indicating that TOM40 mediates the effect of ZBD-2 on PPD. CONCLUSIONS: TOM40 is required for the effect of ZBD-2 on treating anxiety and depression in PPD mice. This study reveals the role of microglia TSPO in PPD development and provides the new therapeutic strategy for PPD.

Latest Advances in Active Materials for Food Packaging and Their Application.

Food packaging plays a pivotal role in preserving the quality and safety of food products while extending their shelf life [...].

A Novel Strategy to Improve Cloud Stability of Orange-Based Juice: Combination of Natural Pectin Methylesterase Inhibitor and High-Pressure Processing.

This study investigated the prospect of producing cloud-stable orange-based juice by combining high-pressure processing (HPP) with a natural kiwifruit pectin methylesterase inhibitor (PMEI) during chilled storage. Kiwifruit is rich in a PMEI, which greatly improves the cloud loss caused by the pectin methylesterase (PME) demethylation of pectin. The results show that the cloud loss of orange juice occurred after 3 days, while the orange-kiwifruit mixed juice and kiwifruit puree were cloud stable during 28 days' storage. Although, the kiwifruit puree contained larger particles compared to the orange juice, its higher viscosity and solid-like behavior were dominant, improving the cloud stability of the juice systems. In addition, the particle size distribution and rheological properties were highly related to PME activity, PMEI activity, and pectin characterization. The kiwifruit PMEI showed higher resistance to HPP and storage time than PME. More water-solubilized pectin fractions with a high molecular mass were found in the kiwifruit puree, leading to its high viscosity and large particle size, but a more chelator-solubilized pectin fraction with a low esterification degree was observed in the orange juice, resulting in its cloud loss. In general, the outcome of this work provides a novel strategy to improve the cloud stability of orange-based juices using natural PMEIs and nonthermal processing technologies.

Chemometric Classification of Apple Cultivars Based on Physicochemical Properties: Raw Material Selection for Processing Applications.

Apple cultivars exhibit significant diversity in fruit quality traits, creating distinct consumption scenarios. This study aimed to assess the physicochemical parameters and sensory attributes differences among fifteen apple cultivars and identify characteristic qualities suitable for various processed apple products using chemometric analysis. Relatively large differences were registered between cultivars for deflection, peel color, titratable acidity (TA), the ratio of total soluble solid to titratable acidity (TSS/TA), hardness, soluble sugar, and volatile organic compound contents. Sensory results showed significant differences existed among the preferences for different processed products. Based on the above results, all cultivars could be distinguished into three main clusters. Cluster I (i.e., Aziteke, Bakeai, Magic Flute, Royal Gala, Red General, Red Delicious, and Zhongqiuwang) demonstrated favorable appearance, high sensory scores, and rich aroma volatile compounds, making them suitable for direct consumption. Cluster II (i.e., Fuburuisi, Sinike, Honglu, and Huashuo) exhibited a higher sugar and acid content, making them suitable for apple juice production. Cluster III (i.e., Miqila, Honey Crisp, Shandong Fuji, and Yanfu 3) were more suitable for fresh-cut apples due to their good flavor and undesirable appearance. Several chemometric analyses effectively assessed differences among apple cultivars.

Effect of pasteurization processing and storage conditions on softening of acidified chili pepper: Pectin and it related enzymes.

The softening of acidified chili peppers induced by processing and storage has become a major challenge for the food industry. This study aims to explore the impact of pasteurization techniques, thermal processing (TP), high-pressure processing (HPP), addition of sodium metabisulfite (SMS), and storage conditions (25 °C, 37 °C, and 42 °C for 30 days) on the texture-related properties of acidified chili pepper. The results showed that the textural properties of samples were destructed by TP (the hardness of samples decreased by 19.43 %) but were less affected by HPP and SMS. Compared with processing, storage temperature had a more dominant impact on texture and pectin characteristics. With increased storage temperature, water-solubilized pectin fraction content increased (increased by 160.99 %, 136.74 %, and 13.01 % in TP, HPP, and SMS-stored groups, respectively), but sodium carbonate-solubilized pectin fraction content decreased (decreased by 29.84 %, 26.81 %, and 8.60 % in TP-, HPP-, and SMS-stored groups, respectively), especially in TP-stored groups. Multivariate data analysis showed that softening was more closely related to pectin conversion induced by acid hydrolysis and pectinase depolymerization. This finding offers new perspectives for the production of acidified chili pepper.

Preparation of garlic stem cellulose nanocrystal/leaf extract/chitosan film for black garlic preservation by electrostatic spraying.

In this study, a novel active chitosan (CH) packaging film that incorporates garlic leaf extract (GL) and stem cellulose nanocrystals (CNC) was prepared. The addition of CNC to the CH film increased its tensile strength, hydrophilicity, thermal stability, and water/oxygen barrier and decreased its water contact angle and weight-loss rate, while the addition of GL greatly enhanced its antioxidant and antibacterial activities. SEM and AFM analyses showed that the CNC agglomerates and deposits in the lower layer and the surface roughness of the film was the highest at 1.2 % concentration. The optimal composition of the film was determined to be 0.8 % CNC and 4 % GL by the fuzzy mathematics evaluation method. Then, black garlic was preserved with the optimized coating by electrostatic spraying and was found to slow water loss and migration, while its excellent antioxidant activities decreased the degree of browning during 90 d of storage.

PJA1 mediates the effects of astrocytic GPR30 on learning and memory in female mice.

Hormone replacement therapy (HRT) is not recommended for treating learning and memory decline in menopausal women because it exerts adverse effects by activating classic estrogen receptors ERα and ERß. The membrane estrogen receptor G protein-coupled receptor 30 (GPR30) has been reported to be involved in memory modulation; however, the underlying mechanisms are poorly understood. Here, we found that GPR30 deletion in astrocytes, but not in neurons, impaired learning and memory in female mice. Astrocytic GPR30 depletion induced A1 phenotype transition, impairing neuronal function. Further exploration revealed that Praja1 (PJA1), a RING ubiquitin ligase, mediated the effects of astrocytic GPR30 on learning and memory by binding to Serpina3n, which is a molecular marker of neuroinflammation in astrocytes. GPR30 positively modulated PJA1 expression through the CREB signaling pathway in cultured murine and human astrocytes. Additionally, the mRNA levels of GPR30 and PJA1 were reduced in exosomes isolated from postmenopausal women while Serpina3n levels were increased in the plasma. Together, our findings suggest a key role for astrocytic GPR30 in the learning and memory abilities of female mice and identify GPR30/PJA1/Serpina3n as potential therapeutic targets for learning and memory loss in peri- and postmenopausal women.

Effect of electroacupuncture combined with rehabilitation training on hypertension: A systematic review and meta-analysis.

To evaluate the clinical effects of electroacupuncture combined with rehabilitation training (EART) versus conventional rehabilitation training (CRT) on hypertension. Multiple databases like PubMed, Embase, Web of Science and Wanfang database, China National Knowledge Internet database, and Chinese Biological Medical database were used to search for the relevant studies and full-text articles involved in evaluating EART versus CRT with hypertension. Review Manager 5.4 was used to estimate the effects of the results among included articles. Forest plots, sensitivity analysis, and funnel plots were also conducted on the included articles. In this meta-analysis study, there were 9 relevant studies were eventually satisfied the included criteria. There were significant differences between EART group and CRT group in systolic blood pressure after treatment (MD -16.62, 95 %CI = -21.84 to -11.39; P < 0.00001), diastolic blood pressure after treatment (MD = -16.03, 95 % CI = -21.55 to -10.50; P < 0.00001), and effective rate (MD = 1.22, 95 % CI = 1.13 to 1.32; P < 0.00001). Sensitivity analysis and funnel chart demonstrated that the study was robust and limited publication bias was observed. Our data showed that EART was clinically more significant than CRT in hypertension. Further studies need to be performed using large relevance references to verify the effectiveness of EART in the treatment of hypertension.

Exploring the mechanism of Akebia trifoliata fruit cracking based on cell-wall metabolism.

Akebia trifoliata fruit cracks easily, but little is known about the underlying mechanism of this process. In this study, the changes in minerals contents, water distribution, phytohormone levels, and reactive oxygen species (ROS) metabolism were investigated to explore the effects of cell-wall metabolism in A. trifoliata fruit cracking. The micro-morphological observation confirmed that A. trifoliata fruit cracking was closely related to the cell-wall metabolism. After cracking, the higher polygalacturonase, ß-1,4-endoglucanase, and ß-glucosidase activities resulted in the depolymerization of covalently bound pectin (from 9.69% to 7.70%) and cellulose (from 57.91% to 38.05%). Moreover, the disordered ROS homeostasis resulted from the lower superoxide dismutase and ascorbate peroxidase activities, which led to cellular oxidative damage. These modifications, together with the decreases in Ca, K, and B, degradation of starch, and the movement of water, decreased cell-wall strength and degraded the cellulose network, and thus resulted in A. trifoliata cracking. The above processes were regulated by phytohormones through increased indole-3-acetic acid, salicylic acid, and jasmonic acid levels, as well as decreased cytokinin content. The findings of this study will be beneficial for further research into the preservation of A. trifoliata fruit, which is of great significance to the development of the A. trifoliata industry.

Combination of chitosan coating and heat shock treatments to maintain postharvest quality and alleviate cracking of Akebia trifoliate fruit during cold storage.

Akebia trifoliata fruit cracks easily, which shortens the shelf life and declines commercial value. This work aimed to evaluate the effects of heat shock and coating treatments on postharvest quality of A. trifoliata fruit and to elucidate the mechanism underlying retarding cracking by cell wall metabolism. Coating could decline cracking incidence (from 16.05% to 3.61%), decay incidence (from 31.21% to 18.06%), total soluble solids (TSS), and malondialdehyde (MDA) content compared to uncoated treatment during 35 days of storage. Heat shock could further decrease decay incidence but did not influence TSS, pH, firmness, and starch. Heat shock at 40 °C combined with coating treatment had the best preservation performance with the highest synthetic score (4.41). Furthermore, coated fruit displayed lower ß-glucosidase and polygalacturonase activities which resulted in higher cellulose and Na2CO3-soluble pectin. These modifications together with lower weight loss, MDA, and ion leakage contributed to the lower cracking incidence.