Sweet Cherry Plants Prioritize Their Response to Cope with Summer Drought, Overshadowing the Defense Response to Pseudomonas syringae pv. syringae.

Disease severity and drought due to climate change present significant challenges to orchard productivity. This study examines the effects of spring inoculation with Pseudomonas syringae pv. syringae (Pss) on sweet cherry plants, cvs. Bing and Santina with varying defense responses, assessing plant growth, physiological variables (water potential, gas exchange, and plant hydraulic conductance), and the levels of abscisic acid (ABA) and salicylic acid (SA) under two summer irrigation levels. Pss inoculation elicited a more pronounced response in 'Santina' compared to 'Bing' at 14 days post-inoculation (dpi), and those plants inoculated with Pss exhibited a slower leaf growth and reduced transpiration compared to control plants during 60 dpi. During differential irrigations, leaf area was reduced 14% and 44% in Pss inoculated plants of 'Bing' and 'Santina' respectively, under well-watered (WW) conditions, without changes in plant water status or gas exchange. Conversely, water-deficit (WD) conditions led to gas exchange limitations and a 43% decrease in plant biomass compared to that under WW conditions, with no differences between inoculation treatments. ABA levels were lower under WW than under WD at 90 dpi, while SA levels were significantly higher in Pss-inoculated plants under WW conditions. These findings underscore the influence on plant growth during summer in sweet cherry cultivars that showed a differential response to Pss inoculations and how the relationship between ABA and SA changes in plant drought level responses.

Effect of preharvest melatonin applications at dusk on quality and bioactive compounds content of early sweet cherries.

BACKGROUND: Early sweet cherries have a high economic impact on cherry growers but have poorer quality characteristics and shorter shelf-life than late cherries. Melatonin has been proposed as a biostimulant that regulates plant and fruit growth and increases fruit quality and shelf-life but, in general in fruit and vegetables, there is controversy about its effects. Therefore, this work aimed to evaluate the impact of exogenous preharvest melatonin applications at dusk on the quality and bioactive compounds of two early sweet cherry cultivars. RESULTS: The M3 and M5 (3 × 10-4 and 5 × 10-4 mol L-1 melatonin, respectively) treatments effectively enhanced the endogenous melatonin and hydroxycinnamic acid concentration, enhancing the functional properties of the fruit. Additionally, the M5 treatment enhanced skin colour and consumer acceptance of 'Samba' cherries, while the M3 treatment improved cherry size in 'Sandon Rose'. CONCLUSION: Preharvest melatonin applications at dusk could be included in the scheduled preharvest treatments for early cherry cultivars in order to improve the quality and to stimulate the functionality of the fruit. However, further studies are needed to adjust the concentration depending on the cultivar and the objective pursued. © 2023 Society of Chemical Industry.

Valorization of Defatted Cherry Seed Residues from Liquor Processing by Matrix Solid-Phase Dispersion Extraction: A Sustainable Strategy for Production of Phenolic-Rich Extracts with Antioxidant Potential.

The integrated valorization of food chain waste is one of the most promising alternatives in the transition to a sustainable bioeconomy. Thus, an efficient solid-phase matrix dispersion extraction method, using experimental factorial design and response surface methodology, has been developed and optimized for the recovery of polyphenols from defatted cherry seeds obtained after cherry liquor manufacture and subsequent fatty acid extraction, evaluating the effect of each processing step on the composition and phenolic content of sweet cherry residues. The phenolic extracts before fermentation showed the highest content of total polyphenols (TPC) and flavonoids (TFC) (3 ± 1 mg QE·g-1 and 1.37 ± 0.08 mg GAE·g-1, respectively), while the highest antioxidant capacity was obtained in the defatted seed extracts after both fermentation and distillation. In addition, high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS) was used to determine the phenolic profile. Dihydroxybenzoic acid, neochlorogenic acid, caffeic acid, and quercetin were the main phenolics found, showing differences in concentration between the stages of liquor production. The results underline the prospective of cherry by-products for obtaining phenol-rich bioactive extracts for possible use in different industrial sectors, offering a feasible solution for the cascade valorization of cherry agri-food waste.

Impact of Pre-Storage Melatonin Application on the Standard, Sensory, and Bioactive Quality of Early Sweet Cherry.

Melatonin (N-acetyl-5-methoxytryptamine) is involved in multiple functions in plants. However, its role in some metabolic pathways and exogenous application's effect on fruits is still unclear. Furthermore, the effects of pre-storage melatonin treatment on sensory traits and consumer acceptance of cherries have yet to be studied. For this reason, the early sweet cherry cultivar 'Samba' harvested at the commercial ripening stage was treated with different melatonin concentrations (0.1, 0.3, and 0.5 mmol L-1) and stored for 21 days under controlled cold temperature and humidity. The standard quality, respiration rate, postharvest aptitude, sensory quality, phenols, and antioxidant systems (non-enzymatic and enzymatic) were analysed at 14 and 21 days of storage. Postharvest treatment with melatonin 0.5 mmol L-1 improved firmness and reduced weight loss and non-commercial fruit percentage while increasing respiration rate, lipophilic antioxidant activity, and ascorbate peroxidase enzyme activity. Furthermore, the treated cherries showed better sensory qualities, such as uniformity of colour and skin colour, as well as being sourer and showing better consumer acceptance and liking after 14 days of storage. Therefore, we conclude that the 0.5 mmol L-1 concentration is effective on the standard, sensory, and bioactive quality of early sweet cherries and can be considered an eco-friendly tool for maintaining the postharvest quality of early cherries.

Orchard Net Covers Improve Resistance to Cherry Cracking Disorder.

Orchard net cover improves plant physiology, yield and fruit quality, pest and disease control, and anticipates fruit ripening. Moreover, this crop technology has been used to reduce natural cherry cracking (NCC). This is a serious physiological disorder that cracks the epidermis, the hypodermis, and the storage parenchyma layers of the fruit due to rainfall events near the harvest and it is related to low fruit osmotic potential and/or high fruit water permeability. This work aims to study the effect of orchard net cover on sweet cherry trees, cv. Early Bigi, in two harvesting years (2019 and 2021). The NCC, the induced cracking index (CI), and the cracking type incidence were determined. In addition, epicuticular and intra-cuticular wax content, biometric and physicochemical parameters were also evaluated. Net cover reduced the natural cracking index by 40%. High fruit weight values were observed in covered trees comparing to the control ones, with increases of 45% and 13%, in 2019 and 2021, respectively. A positive correlation was observed between CI and total soluble solids and a negative correlation between CI and wax content. Therefore, with forecasts of worsening heavy precipitation events near harvest, protecting cherry trees with nets will increase resistance to fruit cracking.

Application of proteomics to determine the mechanism of ozone on sweet cherries (Prunus avium L.) by time-series analysis.

This research investigated the mechanism of ozone treatment on sweet cherry (Prunus avium L.) by Lable-free quantification proteomics and physiological traits. The results showed that 4557 master proteins were identified in all the samples, and 3149 proteins were common to all groups. Mfuzz analyses revealed 3149 candidate proteins. KEGG annotation and enrichment analysis showed proteins related to carbohydrate and energy metabolism, protein, amino acids, and nucleotide sugar biosynthesis and degradation, and fruit parameters were characterized and quantified. The conclusions were supported by the fact that the qRT-PCR results agreed with the proteomics results. For the first time, this study reveals the mechanism of cherry in response to ozone treatment at a proteome level.

Metabolites That Confirm Induction and Release of Dormancy Phases in Sweet Cherry Buds.

Here we report on metabolites found in a targeted profiling of 'Summit' flower buds for nine years, which could be indicators for the timing of endodormancy release (t1) and beginning of ontogenetic development (t1*). Investigated metabolites included chrysin, arabonic acid, pentose acid, sucrose, abscisic acid (ABA), and abscisic acid glucose ester (ABA-GE). Chrysin and water content showed an almost parallel course between leaf fall and t1*. After 'swollen bud', water content raised from ~60 to ~80% at open cluster, while chrysin content decreased and lost its function as an acetylcholinesterase inhibitor. Both parameters can be suitable indicators for t1*. Arabonic acid showed a clear increase after t1*. Pentose acid would be a suitable metabolite to identify t1 and t1*, but would not allow describing the ecodormancy phase, because of its continuously low value during this time. Sucrose reached a maximum during ecodormancy and showed a significant correlation with air temperature, which confirms its cryoprotective role in this phase. The ABA content showed maximum values during endodormancy and decreased during ecodormancy, reaching 50% of its content t1 at t1*. It appears to be the key metabolite to define the ecodormancy phase. The ABA-GE was present at all stages and phases and was much higher than the ABA content and is a readily available storage pool in cherry buds.

Wild sweet cherry, strawberry and bilberry as underestimated sources of natural colorants and bioactive compounds with functional properties.

Wild edible fruits, neglected by the development of commercial agriculture, have recently aroused as a good source of natural colorants and bioactive compounds. These novel uses could cover the recent demand for healthier foods with functional properties. Prunus avium, Fragaria vesca and Vaccinium myrtillus wild fruits were characterized by individual anthocyanin profile and color CIELAB parameters, as well as phenolic fraction. In addition, some bioactivities were evaluated. In P. avium cyanidin-O-deoxyhexosyl-pentoside was the representative anthocyanin, in F. vesca pelargonidin-3-O-glucoside and in V. myrtillus delphinidin-O-hexoside. The three wild edible fruits showed interesting antioxidant activity especially in OxHLIA assays. V. myrtillus was the fruit with the best results for the bacterial growth inhibition, while F. vesca with better fungal growth inhibition. These results evidenced the richness of these wild fruits in bioactive compounds and pigments with antioxidant capacity, therefore, their potential use as natural colorants for healthier food products design.

Genetic and Pomological Determination of the Trueness-to-Type of Sweet Cherry Cultivars in the German National Fruit Genebank.

Genebank collections preserve many old cultivars with ancient breeding history. However, often, cultivars with synonymous or incorrect names are maintained in multiple collections. Therefore, pomological and genetic characterization is an essential prerequisite for confirming trueness-to-type of cultivars in gene bank collections. In our study, 1442 single sweet cherry (Prunus avium L.) trees of the German Fruit Genebank were evaluated according to their trueness-to-type. For this purpose, pomological analysis was performed, in which the accessions were assigned totheir historical cultivar names. The pomological identifications were based on several historical reference sources, such as fruit references from historical cherry cultivar and fruit-stone collections, as well as historical pomological literature sources. In addition, the cherry trees were genetically analyzed for cultivar identity using 16 SSR markers. Based on pomological characterization and genetic analysis for the majority of the trees (86%), cultivar authenticity could be confirmed. Most markers were highly discriminating and powerful for cultivar identification. The cherry collection showed a high degree of genetic diversity, with an expected heterozygosity He = 0.67. Generally, high genetic admixture between cultivars of different geographic origin and year of origin was obtained after STRUCTURE analysis, demonstrating the extensive exchange of genetic information between cherry cultivars in the collection over time. However, the phylogenetic tree calculated by DARwin reflected the geographic origin of selected cherry cultivars. After parentage analysis with CERVUS, paternity could not be confirmed for three cultivars, indicating the necessity of further pedigree analysis for these cultivars. The results of our study underlined the general importance of evaluating the authenticity of cultivars in genebank collections based on genetic and pomological characterization.

The Effect of Pre- and Postharvest Calcium Gluconate Treatments on Physicochemical Characteristics and Bioactive Compounds of Sweet Cherry during Cold Storage.

The effects of pre- and postharvest calcium gluconate (Ca-Glu) treatments on some physicochemical characteristics and bioactive compounds of sweet cherry cv. Sweetheart during cold storage were investigated. For preharvest treatments, the Ca-Glu (1%) solution was applied to the cherry trees two times at 21 and 35 days after full bloom stage. Control trees were sprayed with distilled water at the same days. Sweet cherries, sprayed with and without Ca-Glu, were dipped into cold water (4 °C) containing calcium gluconate (1%) for 30 s and only in cold water (4 °C) as control, after harvest Following each treatment, cherries were placed in plastic boxes and stored at 1 ± 0.5 °C and 90 ± 5% relative humidity for 3 weeks. The weight losses of cherries increased over time but calcium (Ca) treatments, especially pre-and postharvest combination, limited these increases compared to control groups. The best result for suppressing the respiration rate of cherries was also obtained from combined treatment. Moreover, combined treatment delayed the losses of titratable acidity, fruit firmness, decay rate and sensory quality in sweet cherries during storage comparison with the pre or postharvest application of Ca-Glu alone. The effect of Ca-Clu treatments on stem chlorophyll content and antioxidant activity was not significant. Preharvest and combined treatments retarded the loss of ascorbic acid content of cherries compared to postharvest and control treatments. The total phenolic and anthocyanin content increased regularly throughout storage, regardless of treatment; however, Ca treatments delayed the accumulation of these compounds. As a result, the combined Ca-Glu treatment could be a promising method for maintaining some physicochemical characteristics and bioactive compounds in sweet cherries during cold storage.

Antioxidant Systems and Quality in Sweet Cherries Are Improved by Preharvest GABA Treatments Leading to Delay Postharvest Senescence.

γ-Aminobutyric acid (GABA) plays important roles in plant development, including the maintenance of fruit quality when applied as postharvest treatment. However, little information is available about the effects of preharvest GABA treatments. Thus, GABA (10, 50 and 100 mM) was applied as foliar spray at key points of fruit development in three sweet cherry cultivars and over two years. The results show that quality parameters, such as total soluble solid content, titratable acidity and firmness were higher in the fruit from GABA-treated trees than in the controls, either at harvest or during four weeks of cold storage. In addition, the total phenolic and total and individual anthocyanin concentrations were also enhanced by GABA treatments and the fruit color was improved. The activities of the antioxidant enzymes catalase, ascorbate peroxidase and peroxidase were also enhanced by the GABA treatments. The most effective concentration was 50 mM, which led to extending the storage period of sweet cherries with high quality traits to up to four weeks, while for the controls this was two weeks. Thus, GABA treatment had a clear effect on delaying the postharvest ripening and senescence processes in sweet cherries, with an additional effect on enhancing the content of bioactive compounds, such as phenolics and anthocyanins, with antioxidant properties and health benefits.

Transport capacity is uncoupled with endodormancy breaking in sweet cherry buds: physiological and molecular insights.

Introduction: To avoid the negative impacts of winter unfavorable conditions for plant development, temperate trees enter a rest period called dormancy. Winter dormancy is a complex process that involves multiple signaling pathways and previous studies have suggested that transport capacity between cells and between the buds and the twig may regulate the progression throughout dormancy stages. However, the dynamics and molecular actors involved in this regulation are still poorly described in fruit trees. Methods: Here, in order to validate the hypothesis that transport capacity regulates dormancy progression in fruit trees, we combined physiological, imaging and transcriptomic approaches to characterize molecular pathways and transport capacity during dormancy in sweet cherry (Prunus avium L.) flower buds. Results: Our results show that transport capacity is reduced during dormancy and could be regulated by environmental signals. Moreover, we demonstrate that dormancy release is not synchronized with the transport capacity resumption but occurs when the bud is capable of growth under the influence of warmer temperatures. We highlight key genes involved in transport capacity during dormancy. Discussion: Based on long-term observations conducted during six winter seasons, we propose hypotheses on the environmental and molecular regulation of transport capacity, in relation to dormancy and growth resumption in sweet cherry.

Anti-Inflammatory and Antimicrobial Activities of Portuguese Prunus avium L. (Sweet Cherry) By-Products Extracts.

The bioactivity of natural by-products in food and pharmaceutical applications is the subject of numerous studies. Cherry production and processing generates large amounts of biowaste, most of which is not used. The recovery of these by-products is essential for promoting the circular economy and to improving sustainability in the food industry. In this work, we explored the anti-inflammatory and antimicrobial potential of two different extracts from stems, leaves, and flowers of Portuguese cherries. The anti-inflammatory potential was studied on lipopolysaccharide (LPS)-stimulated mouse macrophages (RAW 264.7) by evaluating the effect of by-products on cellular viability and nitric oxide (NO) production. Disc diffusion and minimum inhibitory concentration (MIC) were used to determine antimicrobial activity. The cherry by-products had no cytotoxic effect on RAW 264.7 cells, and were able to inhibit nitrite production in a dose-dependent manner. Moreover, all aqueous infusions showed good antioxidant activity against NO radicals. Moreover, leaf extracts showed the best activity against most of the strains studied. The results revealed, for the first time, interesting anti-inflammatory and antimicrobial properties of cherry by-products. This could potentially be of interest for their therapeutic use in the treatment of inflammation-related diseases or in controlling the growth of microorganisms.

ABA and Not Chilling Reduces Heat Requirement to Force Cherry Blossom after Endodormancy Release.

Models used to predict the onset of fruit tree blossom under changed climate conditions should be physiologically based as much as possible. Pure optimized phenology models carry the risk of unrealistic predictions due to a misinterpretation of metabolic processes. This was the motivation determining the relevant phases for chill and heat accumulation, which induces cherry blossom (cv. Summit). Investigations are based on 8 years of observational and analytical data, as well as on controlled experiments. For 'Summit' buds, to be released from endodormancy, 43 chill portions from 1 September are necessary. After endodormancy release (t1), on average on 30 November, no further chilling is required, because no correlation between chill accumulation during ecodormancy and the subsequent heat accumulation until 'Summit' blossom exist. The declining amount of heat, which induces cherry blossom after t1-shown in several forcing experiments-seems to be the result of the declining bud's abscisic acid (ABA) content, up to ~50% until the beginning of ontogenetic development. Shortly after t1, when the bud's ABA content is high, a huge amount of heat is necessary to induce cherry blossom under controlled conditions. Heat requirement reduces during ecodormancy along with the reduction in the ABA content. According to these findings, plant development during ecodormancy is suppressed by low temperatures in the orchard and a slowly declining bud's ABA content. These results should lead to a better consideration of the ecodormancy phase in phenology models.

Detection of Breeding-Relevant Fruit Cracking and Fruit Firmness Quantitative Trait Loci in Sweet Cherry via Pedigree-Based and Genome-Wide Association Approaches.

Breeding for decreased fruit cracking incidence and increased fruit firmness in sweet cherry creates an attractive alternative to variable results from cultural management practices. DNA-informed breeding increases its efficiency, yet upstream research is needed to identify the genomic regions associated with the trait variation of a breeding-relevant magnitude, as well as to identify the parental sources of favorable alleles. The objectives of this research were to identify the quantitative trait loci (QTLs) associated with fruit cracking incidence and firmness, estimate the effects of single nucleotide polymorphism (SNP) haplotypes at the detected QTLs, and identify the ancestral source(s) of functional haplotypes. Fruit cracking incidence and firmness were evaluated for multiple years on 259 unselected seedlings representing 22 important breeding parents. Phenotypic data, in conjunction with genome-wide genotypic data from the RosBREED cherry 6K SNP array, were used in the QTL analysis performed via Pedigree-Based Analysis using the FlexQTL™ software, supplemented by a Genome-Wide Association Study using the BLINK software. Haplotype analysis was conducted on the QTLs to identify the functional SNP haplotypes and estimate their phenotypic effects, and the haplotypes were tracked through the pedigree. Four QTLs (two per trait) were consistent across the years and/or both analysis methods and validated the previously reported QTLs. qCrack-LG1.1m (the label given to a consistent QTL for cracking incidence on chromosome 1) explained 2-15.1% of the phenotypic variance, while qCrack-LG5.1m, qFirm-LG1.2m, and qFirm-LG3.2m explained 7.6-13.8, 8.8-21.8, and 1.7-10.1% of the phenotypic variance, respectively. At each QTL, at least two SNP haplotypes had significant effects and were considered putative functional SNP haplotypes. Putative low-cracking SNP haplotypes were tracked to an unnamed parent of 'Emperor Francis' and 'Schmidt' and unnamed parents of 'Napoleon' and 'Hedelfingen,' among others, and putative high-firmness haplotypes were tracked to an unnamed parent of 'Emperor Francis' and 'Schmidt,' an unnamed grandparent of 'Black Republican,' 'Rube,' and an unknown parent of 'Napoleon.' These four stable QTLs can now be targeted for DNA test development, with the goal of translating information discovered here into usable tools to aid in breeding decisions.

Metabolites in Cherry Buds to Detect Winter Dormancy.

Winter dormancy is still a "black box" in phenological models, because it evades simple observation. This study presents the first step in the identification of suitable metabolites which could indicate the timing and length of dormancy phases for the sweet cherry cultivar 'Summit'. Global metabolite profiling detected 445 named metabolites in flower buds, which can be assigned to different substance groups such as amino acids, carbohydrates, phytohormones, lipids, nucleotides, peptides and some secondary metabolites. During the phases of endo- and ecodormancy, the energy metabolism in the form of glycolysis and the tricarboxylic acid (TCA) cycle was shut down to a minimum. However, the beginning of ontogenetic development was closely related to the up-regulation of the carbohydrate metabolism and thus to the generation of energy for the growth and development of the sweet cherry buds. From the 445 metabolites found in cherry buds, seven were selected which could be suitable markers for the ecodormancy phase, whose duration is limited by the date of endodormancy release (t1) and the beginning of ontogenetic development (t1*). With the exception of abscisic acid (ABA), which has been proven to control bud dormancy, all of these metabolites show nearly constant intensity during this phase.

Mineral Content and Volatile Profiling of Prunus avium L. (Sweet Cherry) By-Products from Fundão Region (Portugal).

Large amounts of Prunus avium L. by-products result from sweet cherry production and processing. This work aimed to evaluate the mineral content and volatile profiling of the cherry stems, leaves, and flowers of the Saco cultivar collected from the Fundão region (Portugal). A total of 18 minerals were determined by ICP-MS, namely 8 essential and 10 non-essential elements. Phosphorus (P) was the most abundant mineral, while lithium (Li) was detected in trace amounts. Three different preparations were used in this work to determine volatiles: hydroethanolic extracts, crude extracts, and aqueous infusions. A total of 117 volatile compounds were identified using HS-SPME/GC-MS, distributed among different chemical classes: 31 aldehydes, 14 alcohols, 16 ketones, 30 esters, 4 acids, 4 monoterpenes, 3 norisoprenoids, 4 hydrocarbons, 7 heterocyclics, 1 lactone, 1 phenol, and 2 phenylpropenes. Benzaldehyde, 4-methyl-benzaldehyde, hexanal, lilac aldehyde, and 6-methyl-5-hepten-2-one were the major volatile compounds. Differences in the types of volatiles and their respective amounts in the different extracts were found. This is the first study that describes the mineral and volatile composition of Portuguese sweet cherry by-products, demonstrating that they could have great potential as nutraceutical ingredients and natural flavoring agents to be used in the pharmaceutical, cosmetic, and food industries.

Comparative evaluation of phenolic profile and antioxidant activity of new sweet cherry (Prunus avium L.) genotypes in Turkey.

INTRODUCTION: Sweet cherry (Prunus avium L.), one of the most consumed fruits in the world, is rich in phenolic and especially anthocyanin content. OBJECTIVE: The aim of this study was to evaluate the phenolic properties of 11 different sweet cherry genotypes collected from Giresun, Turkey. METHODS: Total phenol, flavonoid, anthocyanin and antioxidant properties were observed spectrophotometrically in three different extraction (conventional, microwave-assisted and ultrasound-assisted) processes. Major phenolic, anthocyanin and antioxidant structures were visually assessed by high-performance thin layer chromatography (HPTLC). Various phenolics in its structure were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: T2 and E5 genotypes had the highest content in terms of total phenol, flavonoid, anthocyanin and antioxidant activity. In HPTLC, cherry samples contained high levels of chlorogenic acid, neochlorogenic acid, p-coumaroylquinic acid, rutin and cyanidin-3 rutinoside. Among the phenolics examined in the LC-MS/MS method, the major compounds in the structure of cherry were found to be chlorogenic acid, rutin and catechin. The T2 genotype had higher phenolics than the other cherry samples (chlorogenic acid 19.3 mg/100 g; catechin; 3.8 mg/100 g; rutin 33.1 mg/100 g). CONCLUSION: As a result, T2 and E5 genotypes had higher phenolic and antioxidant activity compared to other genotypes and commercial cultivars. It can be said that the antioxidant contents of these genotypes are due to the high anthocyanin amount in their structures. In addition, T2 genotype contained more major phenolics than other cherries. In the next stage, it is recommended to carry out studies on the cultivation of these two varieties.

Disclosing the Antioxidant and Neuroprotective Activity of an Anthocyanin-Rich Extract from Sweet Cherry (Prunus avium L.) Using In Vitro and In Vivo Models.

In this study, an autochthonous variety of sweet cherry (Prunus avium L.), namely "Moretta di Vignola", was processed to prepare extracts rich in polyphenols, which were characterized by high-performance liquid chromatography (HPLC) separation coupled to UV/DAD and ESI-MSn analysis. Then, a sweet cherry anthocyanin-rich extract (ACE) was prepared, fully characterized and tested for its activity against Parkinson's disease (PD) in cellular (BV2 microglia and SH-SY5Y neuroblastoma) and in Drosophila melanogaster rotenone (ROT)-induced model. The extract was also evaluated for its antioxidant activity on Caenorhabditis elegans by assessing nematode resistance to thermal stress. In both cell lines, ACE reduced ROT-induced cell death and it decreased, alone, cellular reactive oxygen species (ROS) content while reinstating control-like ROS values after ROT-induced ROS rise, albeit at different concentrations of both compounds. Moreover, ACE mitigated SH-SY5Y cell cytotoxicity in a non-contact co-culture assay with cell-free supernatants from ROT-treated BV-2 cells. ACE, at 50 µg/mL, ameliorated ROT (250 µM)-provoked spontaneous (24 h duration) and induced (after 3 and 7 days) locomotor activity impairment in D. melanogaster and it also increased survival and counteracted the decrease in fly lifespan registered after exposure to the ROT. Moreover, heads from flies treated with ACE showed a non-significant decrease in ROS levels, while those exposed to ROT markedly increased ROS levels if compared to controls. ACE + ROT significantly placed the ROS content to intermediate values between those of controls and ROT alone. Finally, ACE at 25 µg/mL produced a significant increase in the survival rate of nematodes submitted to thermal stress (35 °C, 6-8 h), at the 2nd and 9th day of adulthood. All in all, ACE from Moretta cherries can be an attractive candidate to formulate a nutraceutical product to be used for the prevention of oxidative stress-induced disorders and related neurodegenerative diseases.

Differential thermal analysis reveals the sensitivity of sweet cherry flower organs to low temperatures.

The frequency and severity of spring frosts increase during the budburst in many regions of the world as global warming increases. Variability in the freezing resistance of sweet cherry flower organs during the active growing period has been rarely documented, especially in regard to the sepal, pedicel, receptacle, petal, stamen, and pistil organs of flower at the deacclimation stage. The freezing resistance of flower organs of six sweet cherry cultivars was investigated at regular intervals from the first white stage through the full bloom stage using differential thermal analysis (DTA) for 2019-2020. For most of the cultivars, petal and stamen organs of flower exhibited higher freezing resistance than other flower organs. There were significant differences in frost tolerance among cultivars, and 'Van' and 'Wild Genotype' had a lower level of low temperature exotherms or critical temperatures (LT50 values) in both stages, whereas 'Merton Late' was more sensitive to frost than other cultivars. Additionally, an increase in LT50 values in all cultivars was observed with the progression of the budburst. The results in the present study can increase the certainty of decision-making regarding the timing and methods to increase the air temperature in orchards during spring frost events to prevent frost damage. Larger data sets are required to further validate our results, and future efforts should thus be focused on determining the critical temperatures of flower organs using different measurement techniques.