Exogenous chlorogenic acid inhibits quality deterioration in fresh-cut potato slices.

Fresh-cut potatoes are prone to surface browning and physiological degradation. Chlorogenic acid (CGA), a natural phenolic antioxidant, has demonstrated preservative properties in various postharvest products. However, the underlying mechanisms of its application on maintaining quality remain unclear. Therefore, the effect of exogenous CGA treatment on quality deterioration of potato slices and the mechanisms involved were investigated. Results revealed CGA treatment retarded the browning coloration, suppressed microbial growth and inhibited the declines in starch, and ascorbic acid contents in potato slices. Meanwhile, the treatment activated the phenylpropanoid pathway but decreased the activities of phenolic decomposition-related enzymes such as polyphenol oxidase (PPO) and tyrosinase and downregulated StPPO expression. Moreover, the treated slices exhibited reduced accumulation of reactive oxygen species and increased activity of antioxidant enzymes. Additionally, they displayed enhanced 2,2-diphenyl-1-picrylhydrazyl radicals scavenging capacity and higher ATP levels. Therefore, these findings indicated that CGA treatment was effective for quality maintenance and antioxidant capacity enhancement in fresh-cut potatoes, thereby providing potential strategies for the preservation and processing of fresh-cut produce.

Degradable chitosan-based bioplastic packaging: Design, preparation and applications.

Food packaging is an essential part of food transportation, storage and preservation. Biodegradable biopolymers are a significant direction for the future development of food packaging materials. As a natural biological polysaccharide, chitosan has been widely concerned by researchers in the field of food packaging due to its excellent film-forming property, good antibacterial property and designability. Thus, the application research of chitosan-based food packaging films, coatings and aerogels has been greatly developed. In this review, recent advances on chitosan-based food packaging materials are summarized. Firstly, the development background of chitosan-based packaging materials was described, and then chitosan itself was introduced. In addition, the design, preparation and applications of films, coatings and aerogels in chitosan-based packaging for food preservation were discussed, and the advantages and disadvantages of each research in the development of chitosan-based packaging materials were analyzed. Finally, the application prospects, challenges and suggestions for solving the problems of chitosan-based packaging are summarized and prospected.

Photothermal controlled antibacterial Ta4C3Tx-AgNPs/nanocellulose bioplastic food packaging.

Uncontrolled antibacterial, insufficient barrier and low strength are the bottlenecks of food packaging applications. Herein, Ta4C3Tx nanosheet as a template was used to prepare Ta4C3Tx immobilized silver nanoparticles (Ta4C3Tx-AgNPs), which was compounded with nanocellulose to obtain high-strength and high barrier controllable bactericidal nanocellulose-based bioplastic packaging (CTa-Ag). The results indicated that due to the hydrogen bonding between nanocellulose and Ta4C3Tx, the bridging effect of QCS (quaternized chitosan) and the filling of Ta4C3Tx-AgNPs, the CTa-Ag had tightly stacked microstructure, which endowed them with excellent mechanical properties (4.0 GPa), ultra-low oxygen permeability (0.009 cm3/m2·d·atm) and stable photothermal conversion efficiency. Importantly, the packaging exhibits the ability to control the release of antibacterial active ingredients. Moreover, the synergistic effects of controllable release of nano active factors, photothermal and photocatalysis in CTa-Ag gave it long-lasting antibacterial properties. This study brings new insights into the design and manufacture of multifunctional, controllable and long-lasting antibacterial bioplastic food packaging.

Glutamate application maintains quality and antioxidant capacity of fresh-cut carrots by modulating GABA shunt, phenylpropanoid and ROS metabolism.

The effects of exogenous glutamate treatment on the quality attributes, γ-aminobutyric acid (GABA) shunt, phenylpropanoid pathway, and antioxidant capacity of fresh-cut carrots were investigated. Results showed that glutamate treatment suppressed the increases in lightness and whiteness values, inhibited the degradation of total carotenoids and maintained better flavor and taste in fresh-cut carrots. Moreover, glutamate treatment rapidly promoted the activities of glutamate decarboxylase and GABA transaminase, thus improving the GABA content. It also significantly enhanced the activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, and 4-coumarate coenzyme A ligase and promoted the accumulation of total phenolics as well as the main individual phenolic compounds, including chlorogenic and caffeic acid. In addition, glutamate application activated the reactive oxygen system-related enzyme including peroxidase, superoxide dismutase, ascorbate peroxidase, and catalase activities to maintain higher antioxidant capacity in fresh-cut carrots. These results demonstrated that exogenous glutamate treatment maintained better nutritional quality and alleviated color deterioration by accelerating the accumulation of GABA and phenolics and enhancing the antioxidant capacity in fresh-cut carrots.

Clinical efficacy and mechanism study of mid-frequency anti-snoring device in treating moderate obstructive sleep apnea-hypopnea syndrome.

BACKGROUND: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is primarily caused by airway obstruction due to narrowing and blockage in the nasal and nasopharyngeal, oropharyngeal, soft palate, and tongue base areas. The mid-frequency anti-snoring device is a new technology based on sublingual nerve stimulation. Its principle is to improve the degree of oropharyngeal airway stenosis in OSAHS patients under mid-frequency wave stimulation. Nevertheless, there is a lack of clinical application and imaging evidence. AIM: To investigate the clinical efficacy and mechanisms of a mid-frequency anti-snoring device in treating moderate OSAHS. METHODS: We selected 50 patients diagnosed with moderate OSAHS in our hospital between July 2022 and August 2023. They underwent a 4-wk treatment regimen involving the mid-frequency anti-snoring device during nighttime sleep. Following the treatment, we monitored and assessed the sleep apnea quality of life index and Epworth Sleepiness Scale scores. Additionally, we performed computed tomography scans of the oropharynx in the awake state, during snoring, and while using the mid-frequency anti-snoring device. Cross-sectional area measurements in different states were taken at the narrowest airway point in the soft palate posterior and retrolingual areas. RESULTS: Compared to pretreatment measurements, patients exhibited a significant reduction in the apnea-hypopnea index, the percentage of time with oxygen saturation below 90%, snoring frequency, and the duration of the most prolonged apnea event. The lowest oxygen saturation showed a notable increase, and both sleep apnea quality of life index and Epworth Sleepiness Scale scores improved. Oropharyngeal computed tomography scans revealed that in OSAHS patients cross-sectional areas of the oropharyngeal airway in the soft palate posterior area and retrolingual area decreased during snoring compared to the awake state. Conversely, during mid-frequency anti-snoring device treatment, these areas increased compared to snoring. CONCLUSION: The mid-frequency anti-snoring device demonstrates the potential to enhance various sleep parameters in patients with moderate OSAHS, thereby improving their quality of life and reducing daytime sleepiness. These therapeutic effects are attributed to the device's ability to ameliorate the narrowing of the oropharynx in OSAHS patients.

MXene-NH2/chitosan hemostatic sponges for rapid wound healing.

Effective control of wound bleeding and sustained promotion of wound healing remain a major challenge for hemostatic materials. In this study, the hemostatic sponge with controllable antibacterial and adjustable continuous promotion of wound healing (CMNCu) was prepared by chitosan, aminated MXene and copper ion. Interestingly, the internal topological point-line-surface interaction endowed the CMN-Cu sponge longitudinal staggered tubular porous microstructure, combined with the lipophilic properties obtained by modified MXene, which greatly improved its flexibility, wet elasticity and blood enrichment capacity. In addition, the sponge achieved controlled release of active ingredients, which made it present highly effective antibacterial activity and long-lasting ability to promote wound healing. In vitro and in vivo experiments confirmed that CMN-Cu sponge presented high-efficient hemostatic performance. Last but not least, a series of cell experiments showed that the CMN-Cu sponge had excellent safety as a hemostatic material.

CmCML11 interacts with CmCAMTA5 to enhance γ-aminobutyric acid (GABA) accumulation by regulating GABA shunt in fresh-cut cantaloupe.

The effect of calcium chloride (CaCl2) treatment on γ-aminobutyric acid (GABA) accumulation in fresh-cut cantaloupe and the involved mechanisms were investigated. The result showed that 1% (w/v) CaCl2 treatment increased GABA content and activities of glutamate decarboxylase (GAD) and succinate semialdehyde dehydrogenase (SSADH), while decreased glutamate (Glu) content and GABA transaminase (GABA-T) activities in fresh-cut cantaloupe. CmCML11 and CmCAMTA5 expressions of CaCl2-treated fruit increased by 187.4% and 165.6% than control fruit in the initial 6 h. Besides, expressions of GABA shunt genes, including CmGAD1, CmGAD2, CmGABA-T and CmSSADH were also up-regulated by CaCl2 treatment during early storage. Moreover, acting as a transcriptional activator, CmCAMTA5 could bind to the CG-box in promoters of CmGAD1, CmGABA-T and CmSSADH and activate their transcription. Furthermore, the interaction between CmCML11 and CmCAMTA5 could enhance the transcriptional activation on GABA shunt genes which were regulated by CmCAMTA5. Collectively, our findings revealed that CaCl2 treatment promoted GABA accumulation in fresh-cut cantaloupe via the combined effect of CmCML11 and CmCAMTA5 in the regulation of expressions of CmGAD1, CmGABA-T, and CmSSADH in GABA shunt.

PRMT5 facilitates angiogenesis and EMT via HIF-1α/VEGFR/Akt signaling axis in lung cancer.

Abnormal angiogenesis is a critical factor in tumor growth and metastasis, and protein arginine methyltransferase 5 (PRMT5), a prominent type II enzyme, is implicated in various human cancers. However, the precise role of PRMT5 in regulating angiogenesis to promote lung cancer cell metastasis and the underlying molecular mechanisms are not fully understood. Here, we show that PRMT5 is overexpressed in lung cancer cells and tissues, and its expression is triggered by hypoxia. Moreover, inhibiting or silencing PRMT5 disrupts the phosphorylation of the VEGFR/Akt/eNOS angiogenic signaling pathway, NOS activity, and NO production. Additionally, inhibiting PRMT5 activity reduces HIF-1α expression and stability, resulting in the down-regulation of the VEGF/VEGFR signaling pathway. Our findings indicate that PRMT5 promotes lung cancer epithelial-mesenchymal transition (EMT), which might be possibly through controlling the HIF-1α/VEGFR/Akt/eNOS signaling axis. Our study provides compelling evidence of the close association between PRMT5 and angiogenesis/EMT and highlights the potential of targeting PRMT5 activity as a promising therapeutic approach for treating lung cancer with abnormal angiogenesis.

PpMYB1 and PpNPR1 interact to enhance the resistance of peach fruit to Rhizopus stolonifer infection.

MYB transcription factors play important role in stress-resistance of plants. Nevertheless, the function of MYB TFs in peach Rhizopus rot remains poorly understood. Herein, Pichia guilliermondii treatment activated resistance against Rhizopus stolonifer, as illustrated by reductions in the incidence rate and severity of Rhizopus rot disease, increased enzyme activities and gene expression of chitinase (CHI) and ß-1,3-glucanase (GLU), and enhancement of energy production by inducing the activities and expression of H+-ATPase and Ca2+-ATPase, succinate dehydrogenase (SDH), and cytochrome c oxidase (CCO). Moreover, an R1-type MYB, PpMYB1, from peach fruit was induced during R. stolonifer infection and in response to P. guilliermondii treatment. PpMYB1 activated the transcription of PpCHI-EP3 and PpGLU-like genes and the energy metabolism-related gene PpH+-ATPase1 by directly targeting the MBS element. Importantly, PpMYB1 interacted with PpNPR1 to form a heterodimer, which was conducive to enhancing the activation of target gene transcription. Collectively, our findings suggest that PpMYB1 cooperates with PpNPR1 to positively regulate disease resistance by activating the disease defense system and energy metabolism in peaches.

PRMT5/FGFR3/AKT Signaling Axis Facilitates Lung Cancer Cell Metastasis.

Objectives: This study aims to investigate the function of the protein arginine methyltransferase 5 (PRMT5) and fibroblast growth factor receptor 3 (FGFR3)/Akt signaling axis in the epithelial-mesenchymal transition (EMT) of human lung cancer. Methods: The mRNA and protein expression levels of PRMT5, FGFR3, p-Akt, and EMT markers are determined by quantitative real-time PCR and Western blotting, respectively; the expression and localization of PRMT5, p-Akt, and proliferating cell nuclear antigen are detected by immunofluorescence; the human lung cancer cell proliferation is measured by MTS assay. Results: PRMT5 and FGFR3 are highly expressed in human lung cancer tissues and are closely related to lymphatic metastasis. Moreover, down-regulation of PRMT5 by lentivirus-mediated shRNAs or inhibition of PRMT5 by specific inhibitors attenuates FGFR3 expression, Akt phosphorylation, and lung cancer cell proliferation. Further studies show that silencing PRMT5 impairs EMT-related markers, including vimentin, collagen I, and ß-catenin. Conversely, ectopic expression of PRMT5 increases FGFR3 expression, Akt phosphorylation, and EMT-related markers, suggesting that PRMT5 regulates metastasis probably through the FGFR3/Akt signaling axis. Conclusion: PRMT5/FGFR3/Akt signaling axis controls human lung cancer progression and metastasis and also implies that PRMT5 may serve as a prognostic biomarker and therapeutic candidate for treating lung cancer.

Hydrogen sulfide-induced chilling resistance in peach fruit is performed via sustaining the homeostasis of ROS and RNS.

Hydrogen sulfide (H2S) application impacts on endogenous H2S, reactive oxygen species (ROS), and reactive nitrogen species (RNS) in cold-stored peach fruit were investigated. 20 µL L-1 H2S (NaHS as the donor) efficiently retarded the quality deterioration arising from chilling injury (CI), triggering endogenous H2S production, while enhancing antioxidant systems and ROS generation (NADPH oxidative enzyme). H2S promoted nitric oxide (NO) correlated with the S-nitrosoglutathione reductase (GSNOR)-mediated GSNO reduction, while suppressing the peroxynitrite anion content. As the pivotal coenzyme of ROS and RNS, nicotinamide adenine dinucleotide phosphate (NADPH) levels were elevated by H2S during late-stage storage via the tricarboxylic acid cycle, where reduced NADP-isocitrate dehydrogenase (NADP-ICDH) activity and gene expression. Structural analysis of peach NADP-ICDH (UniProtKB M5WXP5) deduced that Cys79 and Tyr396 are the likeliest targets for S-nitrosylation and nitration, respectively. These results indicate that H2S counteracts the disorders of ROS and RNS to ameliorate CI of peach fruit.

Exogenous 24-epibrassinolide alleviates chilling injury in peach fruit through modulating PpGATA12-mediated sucrose and energy metabolisms.

24-Epibrassinolide (EBR) may act as a modulator for chilling injury in peach fruit during cold storage. In this study, we screened a EBR-induced GATA-type zinc finger protein PpGATA12. The objective of this study was to investigate the potential roles of EBR treatment and transcriptional regulation of PpGATA12 in regulating chilling resistance of peaches. In the current study, we found that EBR treatment promoted the activities and transcriptions of energy and sucrose metabolism-related enzymes, maintained higher ATP content and energy status, improved the accumulation of sucrose and hexose. Furthermore, molecular biology assays suggested that PpGATA12 up-regulated transcriptions of sucrose metabolism-related genes including PpSS and PpNI, and energy metabolism-related genes including PpCCO, PpSDH and PpH+-ATPase. These results provided a new insight that the enhancement of chilling resistance in peach fruit by EBR treatment might be closely related to the regulatory role of PpGATA12 on sucrose and energy metabolisms.

CaCl2 mitigates chilling injury in loquat fruit via the CAMTA5-mediated transcriptional repression of membrane lipid degradation genes.

Loquat fruit is vulnerable to chilling injury (CI) under long-term low temperature storage. The application of calciumchloride (CaCl2) can alleviate CI in loquat fruit, however, the molecular mechanisms remain unclear. In this study, the loquat fruit were immersed in 1 % CaCl2 solution for 10 min and then stored at 1 ± 1 ℃ for 35 d. The results showed that CaCl2 treatment suppressed the increases in internal browning index, electrolyte leakage, and malonaldehyde content in loquat fruit under chilling stress. The internal browning index in CaCl2-treated loquat fruit was 33.34 % lower than that in the control at the end of storage. Meanwhile, CaCl2 treatment delayed the phospholipids degradation, and retained high level of unsaturated/saturated fatty acid ratio, which was 15.21 % higher than that in the control fruit at the end of storage. The CaCl2 treatment also decreased the enzymatic activities and gene expressions of phospholipase D (PLD), phospholipase C (PLC), and lipoxygenase (LOX) in loquat fruit during cold storage. Moreover, a calmodulin-binding transcription activator (CAMTA) transcription factor (TF), EjCAMTA5, was cloned from loquat fruit. The EjCAMTA5 expression was up-regulated by cold stress and CaCl2 treatment. Further investigation revealed that EjCAMTA5 directly bound to the promoters of EjPLC6-like and EjLOX5 to repress their transcription. Taken together, these findings implied that CaCl2 application could activate the EjCAMTA5-mediated transcriptional repression of EjPLC6-like and EjLOX5 genes, which contributed to delaying the degradation of membrane lipid and maintaining the integrity of cell membrane, thereby inhibiting the occurrence of browning in loquat fruit under chilling stress.

Hydrogen Sulfide Treatment Alleviates Chilling Injury in Cucumber Fruit by Regulating Antioxidant Capacity, Energy Metabolism and Proline Metabolism.

Although low-temperature storage could maintain the quality of fruits and vegetables, it may also result in chilling injury (CI) in cold-sensitive produce, such as cucumbers. This can seriously affect their quality." The antioxidant capacity, energy metabolism and proline metabolism of cucumbers treated with hydrogen sulfide (H2S) were studied in this assay. The outcomes displayed that H2S treatment effectively reduced CI and delayed the increase in electrolyte leakage (EL) and malondialdehyde (MDA) content. In addition, the H2S-treated cucumber fruit exhibited higher L* and hue angle values, as well as nutrients such as ascorbic acid (AsA). The H2S-treated fruit showed lower levels of reactive oxygen species (ROS) and higher antioxidant enzyme activities. Meanwhile, H2S treatment also increased the activities of the essential enzymes involved in energy metabolism, including cytochrome C oxidase (CCO), succinate dehydrogenase (SDH), H+-ATPase and Ca2+-ATPase, which improved the energy supply. H2S induced higher ornithine δ-aminotransferase (OAT) and Δ-1-pyrroline-5-carboxylate synthetase (P5CS) activities, and reduced proline dehydrogenase (PDH) activity, promoting the accumulation of proline. These results indicated that H2S could alleviate CI in the cucumber fruit by modulating antioxidant capacity, energy metabolism and proline metabolism, thereby extending the shelf life of postharvest cucumbers.

Genome-wide identification of the CDPK gene family reveals the CDPK-RBOH pathway potential involved in improving chilling tolerance in peach fruit.

Calcium-dependent protein kinase (CDPK), as an essential calcium receptor, plays a major role in the perception and decoding of intracellular calcium signaling in plant development and stress responses. Here, the CDPK gene family was analyzed at the genome-wide level in peach. This study identified 17 PpCDPK gene members from the peach genome, and systematically investigated phylogenetic relationships, conserved motifs, exon-intron structures, chromosome distribution, and cis-acting elements of each PpCDPK gene using bioinformatics. Furthermore, the expression levels of most PpCDPK genes were significantly changed under the CaCl2, EBR, GB, cold shock, hot water treatments, and various temperatures in the cold storage of peach fruits. RNA-seq data showed that PpCDPK2, PpCDPK7, PpCDPK10, and PpCDPK13 were related to postharvest chilling stress in peach. The interaction network of PpCDPK7 protein showed that the interaction between PpCDPK7 and PpRBOH may be the intersectional point of Ca2+ and ROS signal transmission during cold storage of peach fruits. These systematic analyses are helpful to further characterize the regulation of PpCDPKs and CDPK-RBOH mediated signal cascades in postharvest chilling injury in peach fruit.

Amino acid metabolomic analysis involved in flavor quality and cold tolerance in peach fruit treated with exogenous glycine betaine.

Glycine betaine (GB) has been reported to mitigate chilling injury of peach fruit during postharvest cold storage, but the effects of GB treatment on changes of fruit flavor and amino acid metabolism remain unclear. In this study, the changes of organic acids and amino acids in peach fruit treated with GB were analyzed through physiological and metabolomic methods. The results manifested that GB treatment reduced internal browning index and maintained higher contents of total soluble solids, titratable acidity, organic acids and total free amino acids. Electronic tongue analysis exhibited separation between GB-treated and control fruit. Additionally, GB treatment increased proline, polyamines and γ-aminobutyric acid (GABA) contents by higher enzyme activities and upregulated gene expressions of arginine metabolism, GABA shunt pathway and lower enzyme activities and downregulated gene expressions of polyamine degradation pathway. Thus, GB treatment could enhance flavor quality and cold tolerance of peach fruit during low temperature storage.

Hydrogen sulfide alleviates chilling injury in peach fruit by maintaining cell structure integrity via regulating endogenous H2S, antioxidant and cell wall metabolisms.

Effects of hydrogen sulfide (H2S) on chilling injury (CI), H2S, antioxidant and cell-wall metabolisms of refrigerated peaches treated with H2S and hypotaurine (HT, H2S scavenger) were investigated in present study. Results revealed that H2S treatment enhanced endogenous H2S content, which was associated with increased related H2S synthase enzymes activities, while HT showed the opposite results. Moreover, H2S treatment induced the accumulation of ascorbic acid, glutathione and the enhancement of antioxidant enzymes activities compared to control and HT, contributing to lower hydrogen peroxide content and superoxide radical production. Furthermore, H2S suppressed the increase of cell-wall degradation enzymes accompanied by higher levels of water-insoluble pectin, 24% KOH-soluble hemicellulose and cellulose, while HT accelerated these components degradation. Therefore, results indicated that H2S mitigated CI of refrigerated peaches by regulating H2S, antioxidant and cell-wall metabolisms, maintaining higher H2S and antioxidants contents, suppressing cell-wall degradation, thereby contributing to redox homeostasis maintenance and cell structure integrity.

Melatonin-mediated postharvest quality and antioxidant properties of fresh fruits: A comprehensive meta-analysis.

At postharvest, fruits have a short shelf life. Recently, there has been much literature on the effects of melatonin on the postharvest quality of horticultural crops. However, reports of various findings comprise mixed claims and product-specific conclusions. Therefore, a meta-analysis systematically dissects the comprehensive effect on several fruits. In this meta-analysis, standard mean difference (SMD) was adopted using a random-effect model. The study used 36 articles and isolated 24 indicator parameters of postharvest quality and antioxidant properties based on the inclusion criteria. As exhibited in the forest plot, melatonin reduced chilling injury, weight loss, respiration rate, and ethylene content (SMD -0.90, 95% CI [-1.14, -0.65]; I2  = 81%; p < .00001). Similarly, the application of melatonin significantly suppressed electrolyte leakage, malondialdehyde (MDA), hydrogen peroxide, superoxide anion, lipoxygenase, and polyphenol oxidase (SMD -0.89, 95% CI [-1.09, -0.69]; I2  = 70%; p < .00001). In addition, exogenous melatonin application induced endogenous melatonin content, phenolic content, and flavonoid and anthocyanin contents (SMD 1.15, 95% CI [0.91, 1.39]; I2  = 71%; p = .01). Moreover, melatonin treatment enhanced antioxidant activities (catalase, superoxide dismutase, peroxidase, ascorbate peroxidase, and phenylalanine ammonia-lyse) (SMD 1.37, 95% CI [1.03, 1.71]; I2  = 86%; p < .00001). Thus, in the whole study, the overall effect was significantly high in treated fruit (p < .0001), and the overall heterogeneity was above (I2 ) > 70%. In addition, the funnel plot showed symmetry in the most selected studies. To sum up, the result gives a further understanding of melatonin's capabilities in reducing postharvest losses and maintaining the quality of fresh fruits.

γ-aminobutyric acid (GABA) alleviated oxidative damage and programmed cell death in fresh-cut pumpkins.

The regulation of γ-aminobutyric acid (GABA) on plant anti-oxygenation and programmed cell death (PCD) in fresh-cut pumpkins was investigated. Exogenous GABA positively promoted GABA accumulation and alleviated oxidant damage in pumpkins tissue. Pumpkins treated with GABA showed lower electrolyte leakage, reactive oxygen species (ROS) and MDA content, while higher activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) as compared to the non-treated tissues. Our results also found that GABA treatment retarded DNA degradation and cytochrome c release and delayed the apoptosis of pumpkin cells. On the other hand, the inhibitor of GABA generation, 3-mercaptopropionic acid (3-MP) treatment not only accelerated oxidant damage, but also induced cell death involving chromatin condensation, DNA ladder and cytochrome c releasing. Taken together, our present research indicated that exogenous GABA could alleviate the wound-induced oxidative stress and PCD occurrence in fresh-cut pumpkins.

MADS2 regulates priming defence in postharvest peach through combined salicylic acid and abscisic acid signaling.

MADS-box genes play well-documented roles in plant development, but relatively little is known regarding their involvement in defence responses. In this study, pre-treatment of peach (Prunus persica) fruit with ß-aminobutyric acid (BABA) activated resistance against Rhizopus stolonifer, leading to a significant delay in the symptomatic appearance of disease. This was associated with an integrated defence response that included a H2O2 burst, ABA accumulation, and callose deposition. cDNA library screening identified nucleus-localized MADS2 as an interacting partner with NPR1, and this was further confirmed by yeast two-hybrid, luciferase complementation imaging, and co-immunoprecipitation assays. The DNA-binding activity of NPR1 conferred by the NPR1-MADS2 complex was required for the transcription of SA-dependent pathogenesis-related (PR) and ABA-inducible CalS genes in order to gain the BABA-induced resistance, in which MAPK1-induced post-translational modification of MADS2 was also involved. In accordance with this, overexpression of PpMADS2 in Arabidopsis potentiated the transcription of a group of PR genes and conferred fungal resistance in the transgenic plants. Conversely, Arabidopsis mads2-knockout lines showed high sensitivity to the fungal pathogen. Our results indicate that MADS2 positively participates in BABA-elicited defence in peach through a combination of SA-dependent NPR1 activation and ABA signaling-induced callose accumulation, and that this defence is also related to the post-translational modification of MADS2 by MAPK1 for signal amplification.