Overexpression of PavHIPP16 from Prunus avium enhances cold stress tolerance in transgenic tobacco.

BACKGROUND: The heavy metal-associated isoprenylated plant protein (HIPP) is an important regulatory element in response to abiotic stresses, especially playing a key role in low-temperature response. RESULTS: This study investigated the potential function of PavHIPP16 up-regulated in sweet cherry under cold stress by heterologous overexpression in tobacco. The results showed that the overexpression (OE) lines' growth state was better than wild type (WT), and the germination rate, root length, and fresh weight of OE lines were significantly higher than those of WT. In addition, the relative conductivity and malondialdehyde (MDA) content of the OE of tobacco under low-temperature treatment were substantially lower than those of WT. In contrast, peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) activities, hydrogen peroxide (H2O2), proline, soluble protein, and soluble sugar contents were significantly higher than those of WT. Yeast two-hybrid assay (Y2H) and luciferase complementation assay verified the interactions between PavbHLH106 and PavHIPP16, suggesting that these two proteins co-regulated the cold tolerance mechanism in plants. The research results indicated that the transgenic lines could perform better under low-temperature stress by increasing the antioxidant enzyme activity and osmoregulatory substance content of the transgenic plants. CONCLUSIONS: This study provides genetic resources for analyzing the biological functions of PavHIPPs, which is important for elucidating the mechanisms of cold resistance in sweet cherry.

Unveiling the effect of gibberellin-induced iron oxide nanoparticles on bud dormancy release in sweet cherry (Prunus avium L.).

Hydrogen cyanide has been extensively used worldwide for bud dormancy break in fruit trees, consequently enhancing fruit production via expedited cultivation, especially in areas with controlled environments or warmer regions. A novel and safety nanotechnology was developed since the hazard of hydrogen cyanide for the operators and environments, there is an urgent need for the development of novel and safety approaches to replace it to break bud dormancy for fruit trees. In current study, we have systematically explored the potential of iron oxide nanoparticles, specifically α-Fe2O3, to modulate bud dormancy in sweet cherry (Prunus avium). The synthesized iron oxide nanoparticles underwent meticulous characterization and assessment using various techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and ultraviolet-visible infrared (UV-Vis) spectroscopy. Remarkably, when applied at a concentration of 10 mg L-1 alongside gibberellin (GA4+7), these iron oxide nanoparticles exhibited a substantial 57% enhancement in bud dormancy release compared to control groups, all achieved within a remarkably short time span of 4 days. Our RNA-seq analyses further unveiled that 2757 genes within the sweet cherry buds were significantly up-regulated when treated with 10 mg L-1 α-Fe2O3 nanoparticles in combination with GA, while 4748 genes related to dormancy regulation were downregulated in comparison to the control. Moreover, we discovered an array of 58 transcription factor families among the crucial differentially expressed genes (DEGs). Through hormonal quantification, we established that the increased bud burst was accompanied by a reduced concentration of abscisic acid (ABA) at 761.3 ng/g fresh weight in the iron oxide treatment group, coupled with higher levels of gibberellins (GAs) in comparison to the control. Comprehensive transcriptomic and metabolomic analyses unveiled significant alterations in hormone contents and gene expression during the bud dormancy-breaking process when α-Fe2O3 nanoparticles were combined with GA. In conclusion, our findings provide valuable insights into the intricate molecular mechanisms underlying the impact of iron oxide nanoparticles on achieving uniform bud dormancy break in sweet cherry trees.

Functional analysis of sweet cherry PavbHLH106 in the regulation of cold stress.

KEY MESSAGE: Sweet cherry PavbHLH106 was up-regulated under cold induction and overexpressed to enhance the cold resistance in tobacco by mediating the scavenging of ROS through increasing of antioxidant enzyme activity. Sweet cherry (Prunus avium L.) is an economically important fruit. Chilling requirements are critical during dormancy, but abnormally low temperatures unfavorably affect fruit growth and development. Differences were found in the transcript level of PavbHLH106 under salt, dehydration, and low-temperature treatments, especially in response to cold stress, suggesting that this gene is involved in the regulation of different abiotic stresses. PavbHLH106 is homologous to Arabidopsis thaliana AtbHLH106 with a conserved bHLH domain, and transient expression in tobacco suggests that the protein is localized in the nucleus and has transcriptional activity in yeast. The PavbHLH106 overexpression in tobacco resulted in weaker electrolyte leakages, lower malondialdehyde, and higher proline content than the wild type at low-temperature treatment. Reactive oxygen species accumulation was significantly reduced in the overexpressed lines, negatively correlated with the antioxidant enzyme activity. In addition, overexpression of PavbHLH106 delayed the germination of tobacco seeds and promoted plant growth. Resistance-related genes were expressed more in the overexpressed plants compared to the wild type. PavbHLH106 bound to the PavACO promoter in yeast and potentially interacted with a bHLH162-like transcription factor. These results indicate that PavbHLH106 has various functions and is particularly active in controlling low-temperature stress.

Comparative analysis of the difference in flavonoid metabolic pathway during coloring between red-yellow and red sweet cherry (Prunus avium L.).

The color of a fruit is an important contributor to the perception of its nutritional value. It is widely acknowledged that the color of sweet cherry changes obviously during ripening. Variations in anthocyanins and flavonoids account for the heterogeneous color of sweet cherries. In this study, we showed that anthocyanins but not carotenoids determine the color of sweet cherry fruits. The difference between red-yellow and red sweet cherry may be attributed to seven anthocyanins, including Cyanidin-3-O-arabinoside, Cyanidin-3,5-O-diglucoside, Cyanidin 3-xyloside, Peonidin-3-O-glucoside, Peonidin-3-O-rutinoside, Cyanidin-3-O-galactoside, Cyanidin-3-O-glucoside (Kuromanin), Peonidin-3-O-rutinoside-5-O-glucoside, Pelargonidin-3-O-glucoside and Pelargonidin-3-O-rutinoside. The content of 85 flavonols differed between red and red-yellow sweet cherries. The transcriptional analysis identified 15 key structural genes involved in the flavonoid metabolic pathway and four R2R3-MYB transcription factors. The expression level of Pac4CL, PacPAL, PacCHS1, PacCHS2, PacCHI, PacF3H1, PacF3H2, PacF3'H, PacDFR, PacANS1, PacANS2, PacBZ1 and four R2R3-MYB were positively correlated with anthocyanin content (ps < 0.05). PacFLS1, PacFLS2 and PacFLS3 expression was negatively correlated with anthocyanin content but positively correlated with flavonols content (ps < 0.05). Overall, our findings suggests that the heterogeneous expression of structural genes in the flavonoid metabolic pathway accounts for the variation in levels of final metabolites, leading to differences between red 'Red-Light' and red-yellow 'Bright Pearl'.

Copper Amine Oxidase (CuAO)-Mediated Polyamine Catabolism Plays Potential Roles in Sweet Cherry (Prunus avium L.) Fruit Development and Ripening.

Copper amine oxidases (CuAOs) play important roles in PA catabolism, plant growth and development, and abiotic stress response. In order to better understand how PA affects cherry fruit, four potential PavCuAO genes (PavCuAO1-PavCuAO4) that are dispersed over two chromosomes were identified in the sweet cherry genome. Based on phylogenetic analysis, they were classified into three subclasses. RNA-seq analysis showed that the PavCuAO genes were tissue-specific and mostly highly expressed in flowers and young leaves. Many cis-elements associated with phytohormones and stress responses were predicted in the 2 kb upstream region of the promoter. The PavCuAOs transcript levels were increased in response to abscisic acid (ABA) and gibberellin 3 (GA3) treatments, as well as abiotic stresses (NaCl, PEG, and cold). Quantitative fluorescence analysis and high-performance liquid chromatography confirmed that the Put content fell, and the PavCuAO4 mRNA level rose as the sweet cherry fruit ripened. After genetically transforming Arabidopsis with PavCuAO4, the Put content in transgenic plants decreased significantly, and the expression of the ABA synthesis gene NCED was also significantly increased. At the same time, excessive H2O2 was produced in PavCuAO4 transiently expressed tobacco leaves. The above results strongly proved that PavCuAO4 can decompose Put and may promote fruit ripening by increasing the content of ABA and H2O2 while suppressing total free PA levels in the fruit.

The beneficial effect of tart cherry on plasma levels of inflammatory mediators (not recovery after exercise): A systematic review and meta-analysis on randomized clinical trials.

BACKGROUND: Chronic inflammation has been classified as one of the most important threats to health. Scientists suggested that tart cherry (TC) can reduce plasma levels of inflammatory mediators. Therefore, the aim of this study was to summarize the effect of TC on circulating C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among adult participants in non-exercise randomized clinical trials (RCTs). METHODS AND MATERIALS: The eligible English-language RCTs were found by searching databases including PubMed, Web of Science, Cochrane Library, Scopus, and clinical Trials.gov up to May 2022, with no time limit. We used the mean change from baseline and its standard deviation for both intervention and comparison groups to calculate the effect size. The random-effects model proposed by DerSimonian and Laird was used to estimate the overall summary effect and the heterogeneity. We used PRISMA 2020 guidelines to report this study. RESULTS: Ten RCTs were included in this study. The results demonstrated that TC had a significant decreasing effect on plasma CRP level compared with the comparison group (weighted mean differences (WMD) = -0.55 mg/L; 95% confidence interval (CI): - 1.03, - 0.06; p = 0.029), but had no significant effect on plasma IL-6 compared with comparison group (WMD = 0.08 pg/mL; 95% CI: -0.02, 0.17; p = 0.10). The effect of TC consumption on plasma TNF-α level was evaluated in only three studies that showed no significant effects (p>0.05). CONCLUSION: Our results confirmed a significant decreasing effect of TC on CRP. Regarding IL-6 and TNF-α, our study did not present any significant effect of TC.

Comparative Assessment of Phytochemical Compounds and Antioxidant Properties of Kernel Oil from Eight Sour Cherry (Prunus cerasus L.) Cultivars.

New plant oils as a potential natural source of nutraceutical compounds are still being sought. The main components of eight cultivars ('Koral', 'Lucyna', 'Montmorency', 'Naumburger', 'Wanda', 'Wigor', 'Wolynska', and 'Wróble') of sour cherry (Prunus cerasus L.) grown in Poland, including crude fat, protein, and oil content, were evaluated. The extracted oils were analysed for chemical and biological activity. The oils had an average peroxide value of 1.49 mEq O2/kg, acid value of 1.20 mg KOH/g, a saponification value of 184 mg of KOH/g, and iodine value of 120 g I2/100 g of oil. The sour cherry oil contained linoleic (39.1-46.2%) and oleic (25.4-41.0%) acids as the major components with smaller concentrations of α-eleostearic acid (8.00-15.62%), palmitic acid (5.45-7.41%), and stearic acid (2.49-3.17%). The content of sterols and squalene varied significantly in all the studied cultivars and ranged between 336-973 mg/100 g and 66-102 mg/100 g of oil. The contents of total tocochromanols, polyphenols, and carotenoids were 119-164, 19.6-29.5, and 0.56-1.61 mg/100 g oil, respectively. The cultivar providing the highest amounts of oil and characterised by the highest content of PUFA (including linoleic acid), plant sterols, α-and ß-tocopherol, as well as the highest total polyphenol and total carotenoids content was been found to be 'Naumburger'. The antioxidant capacity of sour cherry kernel oils, measured using the DPPH• and ABTS•+ methods, ranged from 57.7 to 63.5 and from 38.2 to 43.2 mg trolox/100 g oil, respectively. The results of the present study provide important information about potential possibilities of application of Prunus cerasus kernel oils in cosmetic products and pharmaceuticals offering health benefits.

Tart Cherry Supplement Enhances Skeletal Muscle Glutathione Peroxidase Expression and Functional Recovery after Muscle Damage.

INTRODUCTION: Montmorency cherry concentrate (MCC) supplementation enhances functional recovery from exercise, potentially due to antioxidant and anti-inflammatory effects. However, to date, supporting empirical evidence for these mechanistic hypotheses is reliant on indirect blood biomarkers. This study is the first to investigate functional recovery from exercise alongside molecular changes within the exercised muscle after MCC supplementation. METHODS: Ten participants completed two maximal unilateral eccentric knee extension trials after MCC or placebo (PLA) supplementation for 7 d before and 48 h after exercise. Knee extension maximum voluntary contractions, maximal isokinetic contractions, single leg jumps, and soreness measures were assessed before, immediately, 24 h, and 48 h after exercise. Venous blood and vastus lateralis muscle samples were collected at each time point. Plasma concentrations of interleukin-6, tumor necrosis factor alpha, C-reactive protein, creatine kinase, and phenolic acids were quantified. Intramuscular mRNA expressions of superoxide dismutase 1 (SOD1), SOD3, glutathione peroxidase 1 (GPX1), GPX3, GPX4, GPX7, catalase, and nuclear factor erythroid 2-related factor 2 and relative intramuscular protein expressions of SOD1, catalase, and GPX3 were quantified. RESULTS: MCC supplementation enhanced the recovery of normalized maximum voluntary contraction 1-s average compared with PLA (postexercise PLA, 59.5% ± 18.0%, vs MCC, 76.5% ± 13.9%; 24 h PLA, 69.8% ± 15.9%, vs MCC, 80.5% ± 15.3%; supplementation effect P = 0.024). MCC supplementation increased plasma hydroxybenzoic, hippuric, and vanillic acid concentrations (supplementation effect P = 0.028, P = 0.002, P = 0.003); SOD3, GPX3, GPX4, GPX7 (supplement effect P < 0.05), and GPX1 (interaction effect P = 0.017) gene expression; and GPX3 protein expression (supplementation effect P = 0.004) versus PLA. There were no significant differences between conditions for other outcome measures. CONCLUSIONS: MCC supplementation conserved isometric muscle strength and upregulated antioxidant gene and protein expression in parallel with increased phenolic acid concentrations.

Comparative chemical analysis of six ancient italian sweet cherry (Prunus avium L.) varieties showing antiangiogenic activity.

In this study, cherry fruits and petioles from six ancient Italian Prunus avium L. varieties (Ferrovia, Capellina, Morellina, Ciambellana, Napoletana, and Bianca), were compared by chemical and bioinformatic analyses and evaluated for their antiangiogenic activity. The highest levels of total phenols and flavonoids were found in Napoletana petioles, and Morellina and Capellina fruits. HPLC-PDA-MS analyses showed similar phenolic profiles for all fruit extracts, with cyanidin-3-O-rutinoside, flavonols glycosides, and quinic acid derivatives as major components. Flavonoid glycosides were found in all petiole extracts, while proanthocyanidins B type were predominant in Capellina, Napoletana and Bianca. Accordingly to their higher polyphenolic content, petiole extracts exhibited stronger radical scavenging activity compared to the fruits. The best antiangiogenic response was exhibited by Morellina, Ferrovia, and Ciambellana petiole extracts, and by Ferrovia, Morellina, and Capellina fruit extracts; by bioinformatic studies rutin and cyanidin 3-O-rutinoside were recognised as the best candidate bioactive compounds. In conclusion, sweet cherry varietes were confirmed as valuable sources of phenols, showing also potential angiomodulator properties.

Fruit quality trait discovery and metabolic profiling in sweet cherry genebank collection in Greece.

The current study characterizes the physicochemical, sensory and bioactive compound traits of twenty-two sweet cherry accessions, namely breeding lines, landraces and modern cultivars, embodying the majority of Greek germplasm. The evaluated accessions differ in several quality traits including colour parameters and textural properties as well as sensory attributes, such as taste intensity and overall acceptance. Significant differences in primary metabolites, including fructose, glucose, sorbitol, malic acid were recorded among tested accessions. All genotypes were rich in polyphenols, primarily in quercetin-3,4-O-diglucoside, esculetin, rutin and neochlorogenic acid. An anthocyanins-related discrimination among accessions was also obtained based on cyanidin-3-O-rutinoside and peonidin glycosides content. Overall, the cultivars 'Tsolakeika' and 'Bakirtzeika' exhibited the higher consumer acceptance while the cultivars 'Vasiliadi' and 'Tragana Edessis-Naousis' and especially the breeding line 'TxAg33' contained high polyphenol levels. These results represent a valuable resource for future breeding efforts for sweet cherry cultivars with improved nutritional quality traits.

Dark Sweet Cherry (Prunus avium) Phenolics Enriched in Anthocyanins Induced Apoptosis in MDA-MB-453 Breast Cancer Cells through MAPK-Dependent Signaling and Reduced Invasion via Akt and PLCγ-1 Downregulation.

Dark sweet cherries (DSCs) are rich source of phenolics known to exert anticancer and anti-invasive activities. This study elucidated the molecular mechanisms underlying the activity of DSC phenolics against MDA-MB-453 breast cancer cells In Vitro. Cells were treated with DSC phenolics in whole extract (WE), and fractions enriched in anthocyanins (ACN) and proanthocyanidins (PCN) at concentrations that inhibited cell growth by 50%. Results showed that DSC phenolics suppressed Akt and PLCγ-1 activation, and inhibited cell motility and invasion, but only ACN reached significance. The extrinsic and intrinsic apoptotic pathways were also activated by DSC phenolics via caspase-8 cleavage and increased Bax/Bcl-2 ratio, with ACN exhibiting significant activation and stronger PARP-1 cleavage. Furthermore, sustained activation of mitogen-activated protein kinases (MAPKs) ERK1/2 and p38 was observed wherein ERK1/2 (U0126) and p38 (SB203580) inhibitors confirmed crosstalk ERK1/2-Akt and MAPK intrinsic mitochondrial pathways. In conclusion, DSC phenolics inhibited MDA-MB-453 breast cancer cells by targeting cell signaling pathways that induce apoptosis and suppress cell invasion, with ACN showing enhanced chemopreventive activities.

Novel insights into the calcium action in cherry fruit development revealed by high-throughput mapping.

KEY MESSAGE: This work provides the first system-wide datasets concerning metabolic changes in calcium-treated fruits, which reveal that exogenously applied calcium may specifically reprogram sweet cherry development and ripening physiognomy. Calcium modulates a wide range of plant developmental processes; however, the regulation of fruit ripening by calcium remains largely uncharacterized. In this study, transcriptome, proteome and metabolome profiling was used to document the responses of sweet cherry fruit to external calcium application (0.5% CaCl2) at 15, 27 and 37 days after full blossom. Endogenous calcium loading in fruit across development following external calcium feeding was accompanied by a reduction in respiration rate. Calcium treatment strongly impaired water-induced fruit cracking tested by two different assays, and this effect depended on the fruit size, water temperature and light/dark conditions. Substantial changes in the levels of numerous polar/non-polar primary and secondary metabolites, including malic acid, glucose, cysteine, epicatechin and neochlorogenic acid were noticed in fruits exposed to calcium. At the onset of ripening, we identified various calcium-affected genes, including those involved in ubiquitin and cysteine signaling, that had not been associated previously with calcium function in fruit biology. Calcium specifically increased the abundance of a significant number of proteins that classified as oxidoreductases, transferases, hydrolases, lyases, and ligases. The overview of temporal changes in gene expression and corresponding protein abundance provided by interlinked analysis revealed that oxidative phosphorylation, hypersensitive response, DNA repair, stomata closure, biosynthesis of secondary metabolites, and proton-pump activity were mainly affected by calcium. This report provides the fullest characterization of expression patterns in calcium-responsive genes, proteins and metabolites currently available in fruit ripening and will serve as a blueprint for future biological endeavors.

Melatonin Accumulation in Sweet Cherry and Its Influence on Fruit Quality and Antioxidant Properties.

Although the effects of melatonin on plant abiotic and biotic stress resistance have been explored in recent decades, the accumulation of endogenous melatonin in plants and its influence on fruit quality remains unclear. In the present study, melatonin accumulation levels and the expression profiles of five synthesis genes were investigated during fruit and leaf development in sweet cherry (Prunus avium L.). Melatonin was strongly accumulated in young fruits and leaves, then decreased steadily with maturation. Transcript levels of PacTDC and PacSNAT were highly correlated with melatonin content in both fruit and leaves, indicating their importance in melatonin accumulation. Furthermore, application of 50 and 100 µmol·L-1 of melatonin to leaves had a greater influence on fruit quality than treatments applied to fruits, by significantly improving fruit weight, soluble solids content, and phenolic content including total phenols, flavanols, total anthocyanins, and ascorbic acid. Meanwhile, melatonin application promoted the antioxidant capacity of fruit assayed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis (3-ethylben zothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP). These results provide insights into the physiological and molecular mechanisms underlying melatonin metabolism of sweet cherry.

Proteomic and metabolic analysis reveals novel sweet cherry fruit development regulatory points influenced by girdling.

Despite the application of girdling technique for several centuries, its impact on the metabolic shifts that underly fruit biology remains fragmentary. To characterize the influence of girdling on sweet cherry (Prunus avium L.) fruit development and ripening, second-year-old shoots of the cultivars 'Lapins' and 'Skeena' were girdled before full blossom. Fruit characteristics were evaluated across six developmental stages (S), from green-small fruit (stage S1) to full ripe stage (stage S6). In both cultivars, girdling significantly altered the fruit ripening physiognomy. Time course fruit metabolomic along with proteomic approaches unraveled common and cultivar-specific responses to girdling. Notably, several primary and secondary metabolites, such as soluble sugars (glucose, trehalose), alcohol (mannitol), phenolic compounds (rutin, naringenin-7-O-glucoside), including anthocyanins (cyanidin-3-O-rutinoside, cyanidin-3-O-galactoside, cyanidin-3.5-O-diglucoside) were accumulated by girdling, while various amino acids (glycine, threonine, asparagine) were decreased in both cultivars. Proteins predominantly associated with ribosome, DNA repair and recombination, chromosome, membrane trafficking, RNA transport, oxidative phosphorylation, and redox homeostasis were depressed in fruits of both girdled cultivars. This study provides the first system-wide datasets concerning metabolomic and proteomic changes in girdled fruits, which reveal that shoot girdling may induce long-term changes in sweet cherry metabolism.

Sour cherry (Prunus cerasus L.) vinegars produced from fresh fruit or juice concentrate: Bioactive compounds, volatile aroma compounds and antioxidant capacities.

In this study, it was aimed to determine the bioactive compounds and volatile aroma compounds of the sour cherry vinegar, and to investigate the usability of concentrated juice instead of the fresh fruit juice in vinegar production. And, two sour cherry vinegars were produced using juices prepareted fresh fruit (FSCJ) and concentrate juice (CSCJ), analyzed for functional and organoleptic aspects. The finding shown that both vinegars produced have rich functional compounds (gallic and chlorogenic acids) and volatile aroma compounds, and sour cherry is ideal for vinegar production. However, the vinegar produced using the CSCJ was more prominent, according to aromatic aspect. These aroma compounds were 3-methyl-1-butanol and eugenol, phenethyl alcohol, 2-phenethyl acetate, acetic, isobutyric, isovaleric, hexanoic and octanoic acids. Within this study, a new way for sour cherry usage, independently of the season were proposed. And, aromatic and functional aspects of sour cherry vinegar were revealed for the first time.

Human mitochondrial carnitine acylcarnitine carrier: Molecular target of dietary bioactive polyphenols from sweet cherry (Prunus avium L.).

The effect of polyphenols, recognized as the principal antioxidant and beneficial molecules introduced with the diet, extracted from sweet cherry (Prunus avium L.) on the recombinant human mitochondrial carnitine/acylcarnitine transporter (CACT) has been studied in proteoliposomes. CACT transport activity, which was strongly impaired after oxidation by atmospheric O2 or H2O2, due to the formation of a disulfide bridge between cysteines 136 and 155, was restored by externally added polyphenols. CACT reduction by polyphenols was time dependent. Spectroscopic analysis of polyphenolic extracts revealed eight most represented compounds in four cultivars. Molecular docking of CACT structural omology model with the most either abundant and arguably bio-available phenolic compound (trans 3-O-feruloyl-quinic acid) of the mix, is in agreement with the experimental data since it results located in the active site close to cysteine 136 at the bottom of the translocation aqueous cavity.

Enhancement of storability and antioxidant systems of sweet cherry fruit by nitric oxide-releasing chitosan nanoparticles (GSNO-CS NPs).

Sweet cherries rapidly depreciate in market value owing to decay and the quick loss of fruit quality after harvest. Therefore, optimum postharvest treatment is crucial for maintaining the qualities of cherries during storage. Here, we tested a new method of postharvest treatment by immersing sweet cherries in nitric oxide-releasing chitosan nanoparticles (GSNO-CS NPs), storing them at 0 °C and evaluating fruit quality over time. The results indicated that GSNO-CS NPs more effectively preserved the quality of cherries during cold storage compared to other methods. Specifically, GSNO-CS NPs reduced fruit weight loss, respiration rate and ethylene production and increased soluble solids content. Additionally, GSNO-CS NPs reduced reactive oxygen species, increased the antioxidant enzyme activity in direct and indirect antioxidant systems, and increased the levels of ascorbic acid and reduced glutathione. Overall, results suggest that treatment with GSNO-CS NPs can effectively preserve the quality of cherries and enhance antioxidant capacity during cold storage.

The uniaxial and coaxial encapsulations of sour cherry (Prunus cerasus L.) concentrate by electrospinning and their in vitro bioaccessibility.

Sour cherry (Prunus cerasus L.) is rich in polyphenols which are known to be protective agents against several diseases. Polyphenols are highly sensitive against temperature, pH, oxygen, and light conditions, leading to low bioaccessibility. In this study, polyphenols of sour cherry concentrate (SCC) were encapsulated by uniaxial or coaxial electrospinning with gelatin or gelatin-lactalbumin. Results showed that phenolic acids had higher encapsulation efficiencies than anthocyanins. Encapsulation efficiencies were found as 89.7 and 91.3% in terms of phenolic acids and 70.3 and 77.8% in terms of flavonoids for the uniaxially electrospun samples with gelatin and gelatin-lactalbumin, respectively. The content of polyphenols in SCC decreased after intestinal tract whereas all electrospun samples showed improved bioaccessibility. According to in vitro digestion results, electrospinning encapsulation provided 8 times better protection of cyanidin-3-glucoside compared to the non-encapsulated SCC. Results showed that especially coaxial electrospinning encapsulation is an effective method for sour cherry polyphenols.

Multi-approach metabolomics analysis and artificial simplified phytocomplexes reveal cultivar-dependent synergy between polyphenols and ascorbic acid in fruits of the sweet cherry (Prunus avium L.).

Fruits of the sweet cherry (Prunus avium L.) accumulate a range of antioxidants that can help to prevent cardiovascular disease, inflammation and cancer. We tested the in vitro antioxidant activity of 18 sweet cherry cultivars collected from 12 farms in the protected geographical indication region of Marostica (Vicenza, Italy) during two growing seasons. Multiple targeted and untargeted metabolomics approaches (NMR, LC-MS, HPLC-DAD, HPLC-UV) as well as artificial simplified phytocomplexes representing the cultivars Sandra Tardiva, Sandra and Grace Star were then used to determine whether the total antioxidant activity reflected the additive effects of each compound or resulted from synergistic interactions. We found that the composition of each cultivar depended more on genetic variability than environmental factors. Furthermore, phenolic compounds were the principal source of antioxidant activity and experiments with artificial simplified phytocomplexes indicated strong synergy between the anthocyanins and quercetins/ascorbic acid specifically in the cultivar Sandra Tardiva. Our data therefore indicate that the total antioxidant activity of sweet cherry fruits may originate from cultivar-dependent interactions among different classes of metabolite.

Expression and Anthocyanin Biosynthesis-Modulating Potential of Sweet Cherry (Prunus avium L.) MYB10 and bHLH Genes.

Anthocyanins are essential contributors to fruit coloration, an important quality feature and a breed determining trait of a sweet cherry fruit. It is well established that the biosynthesis of anthocyanins is regulated by an interplay of specific transcription factors belonging to MYB and bHLH families accompanied by a WD40 protein. In this study, we isolated and analyzed PaWD40, PabHLH3, PabHLH33, and several closely related MYB10 gene variants from different cultivars of sweet cherry, analyzed their expression in fruits with different anthocyanin levels at several developmental stages, and determined their capabilities to modulate anthocyanin synthesis in leaves of two Nicotiana species. Our results indicate that transcription level of variant PaMYB10.1-1 correlates with fruit coloration, but anthocyanin synthesis in Nicotiana was induced by another variant, PaMYB10.1-3, which is moderately expressed in fruits. The analysis of two fruit-expressed bHLH genes revealed that PabHLH3 enhances MYB-induced anthocyanin synthesis, whereas PabHLH33 has strong inhibitory properties.