Temperature and solar irradiation effects on secondary metabolism during ripening of field-grown everbearing strawberries.

The garden strawberry (Fragaria x ananassa Duch.) is cultivated and consumed worldwide because of the pleasant flavor and health-promoting phytochemicals of its false fruits. Monocrop cultivars produce fully ripe strawberries in about one month post-anthesis throughout the spring, while everbearing cultivars undergo additional strawberry production in autumn. In this work, we evaluated the impact of different season-dependent environmental conditions on the ripening program of an everbearing field-gown strawberry variety from autumn 2015 to spring 2016. We combined ad hoc sampling and environmental data collection with LC-MS-based untargeted metabolomics to dissect the effects of cumulative temperature and solar irradiation on fruit quality parameters and secondary metabolism during ripening. Different dynamics in specific sub-groups of metabolites were observed in strawberries experiencing distinct amounts of cumulative temperature and solar irradiation during spring and autumn. The integration of statistical analyses on collected data revealed that solar irradiation mainly affected fruit fresh weight and organic acid levels, whereas temperature had a more selective effect on the accumulation of specific flavonols, anthocyanins, and soluble sugar. These findings are of suitable interest to design further approaches for the study of the complex interactions among environmental conditions and ripening in strawberries grown in a real-world scenario.

Genome-wide gene network uncover temporal and spatial changes of genes in auxin homeostasis during fruit development in strawberry (F. × ananassa).

BACKGROUND: The plant hormone auxin plays a crucial role in regulating important functions in strawberry fruit development. Although a few studies have described the complex auxin biosynthetic and signaling pathway in wild diploid strawberry (Fragaria vesca), the molecular mechanisms underlying auxin biosynthesis and crosstalk in octoploid strawberry fruit development are not fully characterized. To address this knowledge gap, comprehensive transcriptomic analyses were conducted at different stages of fruit development and compared between the achene and receptacle to identify developmentally regulated auxin biosynthetic genes and transcription factors during the fruit ripening process. Similar to wild diploid strawberry, octoploid strawberry accumulates high levels of auxin in achene compared to receptacle. RESULTS: Genes involved in auxin biosynthesis and conjugation, such as Tryptophan Aminotransferase of Arabidopsis (TAAs), YUCCA (YUCs), and Gretchen Hagen 3 (GH3s), were found to be primarily expressed in the achene, with low expression in the receptacle. Interestingly, several genes involved in auxin transport and signaling like Pin-Formed (PINs), Auxin/Indole-3-Acetic Acid Proteins (Aux/IAAs), Transport Inhibitor Response 1 / Auxin-Signaling F-Box (TIR/AFBs) and Auxin Response Factor (ARFs) were more abundantly expressed in the receptacle. Moreover, by examining DEGs and their transcriptional profiles across all six developmental stages, we identified key auxin-related genes co-clustered with transcription factors from the NAM-ATAF1,2-CUC2/ WRKYGQK motif (NAC/WYKY), Heat Shock Transcription Factor and Heat Shock Proteins (HSF/HSP), APETALA2/Ethylene Responsive Factor (AP2/ERF) and MYB transcription factor groups. CONCLUSIONS: These results elucidate the complex regulatory network of auxin biosynthesis and its intricate crosstalk within the achene and receptacle, enriching our understanding of fruit development in octoploid strawberries.

The Genome-Wide Identification of the Dihydroflavonol 4-Reductase (DFR) Gene Family and Its Expression Analysis in Different Fruit Coloring Stages of Strawberry.

Dihydroflavonol 4-reductase (DFR) significantly influences the modification of flower color. To explore the role of DFR in the synthesis of strawberry anthocyanins, in this study, we downloaded the CDS sequences of the DFR gene family from the Arabidopsis genome database TAIR; the DFR family of forest strawberry was compared; then, a functional domain screen was performed using NCBI; the selected strawberry DFR genes were analyzed; and the expression characteristics of the family members were studied by qRT-PCR. The results showed that there are 57 members of the DFR gene family in strawberry, which are mainly expressed in the cytoplasm and chloroplast; most of them are hydrophilic proteins; and the secondary structure of the protein is mainly composed of α-helices and random coils. The analysis revealed that FvDFR genes mostly contain light, hormone, abiotic stress, and meristem response elements. From the results of the qRT-PCR analysis, the relative expression of each member of the FvDFR gene was significantly different, which was expressed throughout the process of fruit coloring. Most genes had the highest expression levels in the full coloring stage (S4). The expression of FvDFR30, FvDFR54, and FvDFR56 during the S4 period was 8, 2.4, and 2.4 times higher than during the S1 period, indicating that the DFR gene plays a key role in regulating the fruit coloration of strawberry. In the strawberry genome, 57 members of the strawberry DFR gene family were identified. The higher the DFR gene expression, the higher the anthocyanin content, and the DFR gene may be the key gene in anthocyanin synthesis. Collectively, the DFR gene is closely related to fruit coloring, which lays a foundation for further exploring the function of the DFR gene family.

FaTEDT1L of Octoploid Cultivated Strawberry Functions as a Transcriptional Activator and Enhances Abiotic Stress Tolerance in Transgenic Arabidopsis.

Plants may encounter abiotic stresses, such as drought, flooding, salinity, and extreme temperatures, thereby negatively affecting their growth, development, and reproduction. In order to enhance their tolerance to such stresses, plants have developed intricate signaling networks that regulate stress-responsive gene expression. For example, Arabidopsis Enhanced Drought Tolerance1/HOMEODOMAIN GLABROUS 11 (AtEDT1/HDG11), one of the transcription factor genes from the group IV of homeodomain-leucine zipper (HD-ZIP) gene family, has been shown to increase drought tolerance in various transgenic plants. However, the underlying molecular mechanisms of enhanced stress tolerance remain unclear. In this study, we identified a homologous gene related to AtEDT1/HDG11, named FaTEDT1L, from the transcriptome sequencing database of cultivated strawberry. Phylogenetic analysis revealed the close relationship of FaTEDT1L with AtEDT1/HDG11, which is one of the group IV members of the HD-ZIP gene family. Yeast one-hybrid analysis showed that FaTEDT1L functions as a transcriptional activator. Transgenic Arabidopsis plants overexpressing FaTEDT1L under the control of the cauliflower mosaic virus (CaMV) 35S promoter exhibited significantly enhanced tolerance to osmotic stress (both drought and salinity) when compared to the wild-type (WT) plants. Under osmotic stress, the average root length was 3.63 ± 0.83 cm, 4.20 ± 1.03 cm, and 4.60 ± 1.14 cm for WT, 35S::FaTEDT1L T2 #3, and 35S:: FaTEDT1L T2 #5, respectively. Substantially increased root length in 35S::FaTEDT1L T2 #3 and 35S::FaTEDT1L T2 #5 was noted when compared to the WT. In addition, the average water loss rates were 64%, 57.1%, and 55.6% for WT, 35S::FaTEDT1L T2 #3, and 35S::FaTEDT1L T2 #5, respectively, after drought treatment, indicating a significant decrease in water loss rate of 35S:: FaTEDT1L T2 #3 and 35S::FaTEDT1L T2 #5 is a critical factor in enhancing plant drought resistance. These findings thus highlight the crucial role of FaTEDT1L in mitigating drought and salt stresses and regulating plant osmotic stress tolerance. Altogether, FaTEDT1L shows its potential usage as a candidate gene for strawberry breeding in improving crop resilience and increasing agricultural productivity under adverse environmental conditions.

Chlamydomonas sp. extract meliorates the growth and physiological responses of 'Camarosa' strawberry (Fragaria × ananassa Duch) under salinity stress.

Microalgae like Chlamydomonas are beneficial organisms employed as biological stimulants to improve plants' growth, fruit quality, and stress tolerance. In the current study, the effects of Chlamydomonas sp. foliar spraying (0, 20, and 40 ml L-1) were assayed on Camarosa strawberry plants under salinity stress (0, 40, and 80 mM NaCl). The results showed that the foliar application of Chlamydomonas extract influenced strawberry's morphological, physiological, and biochemical characteristics under salinity stress. Foliar treatment of Chlamydomonas extract with and without salinity stress increased the leaf number and leaf area, the leaf relative water content, and photosynthetic pigments content. Moreover, the foliar application of Chlamydomonas extract decreased lipid peroxidation and hydrogen peroxide content and, on the other hand, enhanced the antioxidant enzymes activity (superoxide dismutase, guaiacol peroxidase, and peroxidase), phenolics, flavonoids, and anthocyanins content under salinity stress. For instance, the highest total antioxidant capacity was found in the plants foliar treated with 40 ml L-1 of Chlamydomonas algae extract under 80 mM salinity stress, which increased by 102.4% compared to the controls, as well as the highest total phenolic compounds and anthocyanin's content were 30.22, and 7.2% more than the control plants, respectively. Overall, the foliar application of Chlamydomonas algae extracts, especially at a concentration of 20 ml L-1 enhanced the strawberry's growth, yield, and physiological traits under saline conditions. The results with more detailed evaluations will be advisable for the pioneer farmers and extension section.

Phenotyping 172 strawberry genotypes for water soaking reveals a close relationship with skin water permeance.

Water soaking is a commercially important disorder of field-grown strawberries that is exacerbated by surface wetness and high humidity. The objective was to establish the effect of genotype on susceptibility to water soaking. Three greenhouse-grown model 'collections' were used comprising a total of 172 different genotypes: (1) a segregating F2 population, (2) a collection of strawberry cultivars and breeding clones, and (3) a collection of wild Fragaria species. A standardized immersion assay was used to induce water soaking. Potential relationships between water soaking and water uptake characteristics, depth of the achene depressions, fruit firmness, cuticle mass and strain relaxation and microcracking were investigated. Further, the effect of downregulating the polygalacturonase genes (FaPG1 and FaPG2) on the susceptibility to water soaking was investigated. The collection of wild species was most susceptible to water soaking. This was followed by the collection of cultivars and breeding clones, and by the F2 population. Susceptibility to water soaking was strongly correlated with water uptake rate (mass of water, per fruit, per time). For the pooled dataset of 172 genotypes, 46% of the variability in water soaking was accounted for by the permeance of the skin to osmotic water uptake. Susceptibility to water soaking was not, or was only poorly correlated with measurements of fruit surface area or of the osmotic potential of the expressed fruit juice. The only exceptions were the wild Fragaria species which were highly variable in fruit size and also in fruit osmotic potential. For genotypes from the F2 and the wild species collections, firmer fruit were less susceptible to water soaking than softer fruit. There were no relationships between fruit firmness and susceptibility to water soaking in transgenic plants in which FaPG1 and FaPG2 were down-regulated. Susceptibility to water soaking was not related to cuticle mass per unit fruit surface area, nor to strain relaxation of the cuticle upon isolation, nor to achene position. In summary, strawberry's susceptibility to water soaking has a significant genetic component and is closely and consistently related to the skin's permeance to osmotic water uptake.

Animal pollination shapes fruits market features, seeds functional traits and modulates their chemistry.

In this study, we experimentally addressed the impact of different pollination treatments on the morphological, reproductive and chemical traits of fruits and seeds of two crop species, the wild strawberry (Fragaria vesca L.) and cowpea (Vigna unguiculata (L.) Walp.). Multiple flowers from each plant were exposed to different pollination treatments: (1) self pollination, (2) hand cross pollination and (3) open pollination. Both crops were positively affected by open pollination in terms of morpho-chemical parameters concerning the marketability (e.g., 35% decrease in sugar/acid ratio in open pollinated strawberries compared to the autogamous ones) and the seed germination rate as a proxy of reproduction efficiency (e.g., the almost complete absence of seed abortion in the open pollination treatment). Remarkably, the pollination treatment also strongly influenced the phytochemical composition. Open-pollinated strawberries exhibited a higher relative concentration of compounds endowed with nutraceutical properties such as anthocyanins, ellagic acid derivatives and flavonoids. At the same time, cowpea seeds displayed higher concentrations of anti-nutrients in the self pollination treatments, such as saponins, compared to the open and hand cross pollinated seeds. This study suggests the presence of a link between the pollination mechanism, market quality, plant reproduction and chemical properties of fruits and seeds, supporting the intricate interplay between pollinators, plants and human nutrition, highlighting the crucial importance of animal pollination in the ecological and dietary contexts.

Combining transcriptomics and HPLC to uncover variations in quality formation between 'Benihoppe' and 'Fenyu No.1' strawberries.

'Benihoppe' and 'Fenyu No.1' are representative varieties of red and pink strawberries in China, possess distinct hue and flavor profiles. This study analyzed the underlying biochemical and molecular differences of two varieties utilizing transcriptomics and high-performance liquid chromatography (HPLC). Ripening 'Benihoppe' fruits accumulated more sucrose and pelargonin-3-glucoside (P3G) with a little cyanidin and higher firmness. Whereas ripening 'Fenyu No.1' fruits contained more fructose, glucose, malic acid and ascorbic acid (AsA), but less P3G and citric acid. Moreover, genotype significantly influenced phenolic compounds contents in strawberries. Transcriptome analysis revealed that pectin degradation (PL, PG, PE), sucrose synthesis (CWINV, SUS, TPS) and citric acid metabolism (α-OGDH, ICDH, GAD, GS, GDH, PEPCK, AST) were weakened in 'Benihoppe' fruit. In contrast, the synthesis of sucrose (CWINH, SPS), citric acid (CS, PEPC), anthocyanin (F3H, F3'H, F3'5'H, DFR, UFGT and ANS), and citric acid transport (V-ATPase) was enhanced. In 'Fenyu No.1' fruit, the degradation of sucrose, citric acid, and pectin was enhanced, along with the synthesis of malic acid (ME) and ascorbic acid (PMM, MDHAR and GaLUR). However, anthocyanins synthesis, glucose metabolism (HK, G6PI, PFK, G6PDH, PGK, PGM, ENO, PK), fructose metabolism (FK), citric acid synthesis and transport, and AsA degradation (AO, APX) were relatively weak. RT-qPCR results corroborated the transcriptome data. In conclusion, this study revealed the distinctions and characteristics of strawberries with different fruit colors regarding texture, flavor and color formation processes. These findings offer valuable insights for regulating metabolic pathways and identifying key candidate genes to improve strawberry quality.

Effect of coatings containing 1-methylcyclopropane or mandarin peel extract on the freshness and metabolic profiles of cold stored strawberry.

The application of coatings is a strategy for maintaining the freshness of highly perishable fruits. This research aimed to evaluate the quality indices of strawberries (Amaou) coated with new coatings based on the sodium carboxymethyl cellulose (CMC) and cellulose nanofibres (CNF) with incorporated mandarin peel extract (ME) or 1-methylcyclopropene (1-MCP) during storage at 20days at 5 °C and 85% relative humidity (RH). Dissolving the coating solution containing ME in 1-MCP maintained its colour for up to 50 days. Coatings enhanced with ME and/or 1-MCP maintained fresh strawberries more effectively than the control, reducing weight loss and maintaining firmness, total soluble solids (TSS), citric acid, colour, and total phenolic content. The CCM2-2 coating solution showed superior effects on the weight loss and relative percentages of strawberry metabolites compared to the other coatings, as confirmed by the different components.

Chitosan-based sustainable packaging and coating technologies for strawberry preservation: A review.

Strawberry fruits are popular all over the world due to their rich organoleptic properties and enormous health benefits. However, it is highly susceptible to postharvest spoilage due to various factors, including moisture loss, nutrient oxidation, and microbial spoilage. Recently, various researchers have studied the effect of chitosan-based flexible films and surface coatings on the shelf life of strawberries. Despite various reviews providing general information on the effects of chitosan-based films and coatings on various food products, no review has focused solely on their effects on postharvest preservation and the shelf life of strawberries. The purpose of this review is to summarize the current research on chitosan-based formulations for extending the shelf life of strawberries. Chitosan, a cationic carbohydrate polymer, possesses excellent properties such as film formation, mechanical strength, non-toxicity, biodegradability, edibility, UV-blocking ability, antioxidant activity, and antibacterial functionality, justifying its potential as packaging/coating material for fresh agricultural products, including strawberries. This review covers the various factors responsible for strawberry spoilage and the properties of chitosan that help counteract these factors. Additionally, the advantages of chitosan-based preservation technology compared to existing strawberry preservation methods were explained, efficiency was evaluated, and future research directions were suggested.

Flexible and wearable sensor for in situ monitoring of gallic acid in plant leaves.

Gallic acid (GA) is one of the main phenolic components naturally occurring in many plants and foods and has been a subject of increasing interest owing to its antioxidant and anti-mutagenic properties. This study introduces a novel flexible sensor designed for in situ detecting GA in plant leaves. The sensor employs a laser-induced graphene (LIG) flexible electrode, enhanced with MXene and molybdenum disulfide (MoS2) nanosheets. The MXene/MoS2/LIG flexible sensor not only demonstrates exceptional mechanical properties, covering a wide detection range of 1-1000 µM for GA, but also exhibits remarkable selectivity and stability. The as-prepared sensor was successfully applied to in situ determination of GA content in strawberry leaves under salt stress. This innovative sensor opens an attractive avenue for in situ measurement of metabolites in plant bodies with flexible electronics.

Development of a multifunctional active food packaging membrane based on electrospun polyvinyl alcohol/chitosan for preservation of fruits.

To mitigate environmental impacts in food preservation, the development of a multifunctional membrane for packaging is of importance. In this study, we have successfully fabricated a nanofibrous membrane using an eco-friendly electrospinning technique, comprising polyvinyl alcohol (PVA), chitosan (CS), and tannic acid (TA). The resulting nanofibrous membranes were crosslinked with glutaraldehyde (GA) and surface modified with ZnO. Our findings demonstrate that the crosslinking process enhances water resistance, reduces water vapor permeability, improves tensile strength (from 3 to 18 MPa), and enhances thermal stability (increasing decomposition temperature from 225 °C to 310 °C). Furthermore, the incorporation of TA and ZnO provides antioxidant properties to the membrane, effectively preventing food decomposition caused by UV-induced oxidation. Additionally, CS, TA, and ZnO synergistically exhibit a remarkable antibacterial effect with a bacteriostasis rate exceeding 99.9 %. The strawberry fresh-keeping experiment further confirms that our developed membrane significantly extends shelf life by up to 6 days. Moreover, cytotoxicity assays confirm the non-toxic nature of these membranes. The innovative significance of this study lies in proposing a robust GA-PVA/CS/TA@ZnO nanofibrous membrane with excellent mechanical properties, biocompatibility, and multiple functionalities including antibacterial, anti-ultraviolet, and anti-oxidation capabilities. It has tremendous potential for applications in active food packaging materials.

In-situ electrospinning PVB/Camellia oil/ZnO-TiO2 nanofibrous membranes with synergistic antibacterial and degradation of ethylene applied in fruit preservation.

This work utilizes a handheld electrospinning device to prepare a novel nanofibrous composite membrane in situ for packaging freshness. It can realize pick-and-pack and is easy to operate. The nanofibrous membrane is based on PVB as the matrix material, adding Camellia oil (CO) and ZnO-TiO2 composite nanoparticles (ZT) as the active material. The antimicrobial property of the CO and the photocatalytic activity of the nanoparticles give the material good antimicrobial and ethylene degradation functions. Meanwhile, this nanofibrous membrane has good mechanical properties, suitable moisture permeability and good optical properties. The nanofibrous membrane are suitable for both climacteric and non- climacteric fruits. Its use as a cling film extends the shelf life of strawberries by 4 days and significantly slows the ripening of small tomatoes. Therefore, this nanofibrous membrane has great potential for application in the field of fruit preservation.

Antagonistic Strain Bacillus velezensis JZ Mediates the Biocontrol of Bacillus altitudinis m-1, a Cause of Leaf Spot Disease in Strawberry.

Biofertilizers are environmentally friendly compounds that can enhance plant growth and substitute for chemically synthesized products. In this research, a new strain of the bacterium Bacillus velezensis, designated JZ, was isolated from the roots of strawberry plants and exhibited potent antagonistic properties against Bacillus altitudinis m-1, a pathogen responsible for leaf spot disease in strawberry. The fermentation broth of JZ exerted an inhibition rate of 47.43% against this pathogen. Using an optimized acid precipitation method, crude extracts of lipopeptides from the JZ fermentation broth were obtained. The crude extract of B. velezensis JZ fermentation broth did not significantly disrupt the cell permeability of B. altitudinis m-1, whereas it notably reduced the Ca2+-ATPase activity on the cell membrane and markedly elevated the intracellular reactive oxygen species (ROS) concentration. To identify the active compounds within the crude extract, QTOF-MS/MS was employed, revealing four antimicrobial compounds: fengycin, iturin, surfactin, and a polyene antibiotic known as bacillaene. The strain JZ also produced various plant-growth-promoting substances, such as protease, IAA, and siderophore, which assists plants to survive under pathogen infection. These findings suggest that the JZ strain holds significant potential as a biological control agent against B. altitudinis, providing a promising avenue for the management of plant bacterial disease.

Internal quality prediction technology for 'Sulhyang' strawberry fruit using organic analysis and hyperspectral imaging.

In recent years, hyperspectral imaging combined with machine learning techniques has garnered significant attention for its potential in assessing fruit maturity. This study proposes a method for predicting strawberry fruit maturity based on the harvest time. The main features of this study are as follows. 1) Selection of wavelength band associated with strawberry growth season; 2) Extraction of efficient parameters to predict strawberry maturity 3) Prediction of internal quality attributes of strawberries using extracted parameters. In this study, experts cultivated strawberries in a controlled environment and performed hyperspectral measurements and organic analyses on the fruit with minimal time delay to facilitate accurate modeling. Data augmentation techniques through cross-validation and interpolation were effective in improving model performance. The four parameters included in the model and the cumulative value of the model were available for quality prediction as additional parameters. Among these five parameter candidates, two parameters with linearity were finally identified. The predictive outcomes for firmness, soluble solids content, acidity, and anthocyanin levels in strawberry fruit, based on the two identified parameters, are as follows: The first parameter, ps, demonstrated RMSE performances of 1.0 N, 2.3 %, 0.1 %, and 2.0 mg per 100 g fresh fruit for firmness, soluble solids content, acidity, and anthocyanin, respectively. The second parameter, p3, showed RMSE performances of 0.6 N, 1.2 %, 0.1 %, and 1.8 mg per 100 g fresh fruit, respectively. The proposed non-destructive analysis method shows the potential to overcome the challenges associated with destructive testing methods for assessing certain internal qualities of strawberry fruit.

Microcystin-degrading bacteria reduce bioaccumulation in Fragaria vulgaris and enhance fruit yield and quality.

In Morocco, red fruit production has thrived, primarily utilizing hydroponic methods to control crops, increase fruit yield and quality, and avoid soil-related problems. However, the irrigation of these expansive hydroponic farms relies heavily on water sourced from dams, many of which are contaminated with Microcystins (MCs). To address this contamination issue, ongoing research is focused on discovering effective and cost-efficient biological solutions for eliminating MCs. In this study, we isolate and identify bacterial strains capable of degrading MCs, evaluate the rate of degradation, and investigate how soil inoculated with these bacteria affects the accumulation of MCs in plant tissue. The partial 16S rRNA analyses of three bacterial sequences were conducted, identifying them through NCBI as follows: Ensifer sp. (B1) isolated from soil, Shinella sp. (B2) from a cyanobacterial bloom, and Stutzerimonas sp. (B3) from water. These bacteria exhibited the ability to degrade MCs, with approximately 34.75%, 73.75%, and 30.1% of the initial concentration (20 µg/L) being removed after a 6-day period for B1, B2, and B3, respectively. Moreover, strawberry plants were cultivated hydroponically in a greenhouse for a duration of 90 days. These plants were subjected to extracts of cyanobacteria containing 10 and 20 µg/L of Microcystins (MC), as well as water from an artificial lake contaminated with MC, both with and without the presence of isolated bacterial strains. Among these strains, Shinella sp. exhibited the highest efficacy in mitigating MC accumulation. Specifically, it resulted in a reduction of approximately 1.159 µg of MC per kilogram of root dry weight, leading to complete elimination in the leaves and fruits. The findings also indicated that the inoculation of perlite with the three MC-degrading bacterial strains significantly enhanced growth, photosynthetic pigments, yield, biochemical constituents, and quality attributes of strawberries (p ≤ 0.05). These promising outcomes suggest the potential of this approach for addressing the adverse impacts of crops irrigated with MC-contaminated water in future agricultural practices.

Chemical and Thermal Characteristics of PEF-Pretreated Strawberries Dried by Various Methods.

By increasing the permeability of the cell membrane of the treated material, pulsed electric fields (PEF) enhance the internal transport of various chemical substances. Changing the distribution of these components can modify the chemical and thermal properties of the given material. This study aimed to analyze the impact of PEF (1 kV/cm; 1 and 4 kJ/kg) applied to strawberries prior to drying by various methods (convective, infrared-convective, microwave-convective, and vacuum) on the chemical and thermal properties of the obtained dried materials (sugars content, total phenolic content, and antioxidant capacity (ABTS and DPPH assays); thermal properties (TGA and DSC); and molecular composition (FTIR)). PEF could have induced and/or enhanced sucrose inversion because, compared to untreated samples, PEF-pretreated samples were characterized by a lower share of sucrose in the total sugar content but a higher share of glucose and fructose. Reduced exposure to oxygen and decreased drying temperature during vacuum drying led to obtaining dried strawberries with the highest content of antioxidant compounds, which are sensitive to these factors. All PEF-pretreated dried strawberries exhibited a lower glass transition temperature (Tg) than the untreated samples, which confirms the increased mobility of the system after the application of an electric field.

Metabolomic and transcriptomic integration reveals the mechanism of aroma formation as strawberries naturally turn colors while ripening.

Aroma is an important indicator of fruit flavor, but mechanisms of aroma formation in strawberries (Fragaria spp.) during natural ripening are still not clear. In this study, aroma compounds in strawberry cultivars were analyzed using gas chromatography-mass spectrometry (GC-MS). Richly creamy strawberry cultivars in particular expressed high levels of vanillin acetate and coumarin (up-regulated by 12.6- and 9.8-fold, respectively), while the aroma-free cultivars were dominated by differential changes in terpenes and alcohols. Further research using liquid chromatography-mass spectrometry (LC-MS) and RNA-Seq indicated that the activation of the phenylpropanoid biosynthesis and alpha-linolenic acid metabolic pathways constituted the key to formation of aroma compounds in creamy strawberry cultivars. The results of this study not only provide a well-defined database to detect aroma compounds in different strawberry cultivars but also explore the underlying mechanisms of creamy aroma formation in strawberries.

Utilizing High-Resolution Imaging and Artificial Intelligence for Accurate Leaf Wetness Detection for the Strawberry Advisory System (SAS).

In strawberry cultivation, precise disease management is crucial for maximizing yields and reducing unnecessary fungicide use. Traditional methods for measuring leaf wetness duration (LWD), a critical factor in assessing the risk of fungal diseases such as botrytis fruit rot and anthracnose, have been reliant on sensors with known limitations in accuracy and reliability and difficulties with calibrating. To overcome these limitations, this study introduced an innovative algorithm for leaf wetness detection systems employing high-resolution imaging and deep learning technologies, including convolutional neural networks (CNNs). Implemented at the University of Florida's Plant Science Research and Education Unit (PSREU) in Citra, FL, USA, and expanded to three additional locations across Florida, USA, the system captured and analyzed images of a reference plate to accurately determine the wetness and, consequently, the LWD. The comparison of system outputs with manual observations across diverse environmental conditions demonstrated the enhanced accuracy and reliability of the artificial intelligence-driven approach. By integrating this system into the Strawberry Advisory System (SAS), this study provided an efficient solution to improve disease risk assessment and fungicide application strategies, promising significant economic benefits and sustainability advances in strawberry production.

Sorbitol metabolism plays a key role in the differential accumulation of sugar in two plum cultivars.

Sugar is vital for plant growth and determines fruit quality via its content and composition. This study explores the differential sugar accumulation in two plum varieties, 'Fengtangli (FTL)' and 'Siyueli (SYL)'. The result showed that 'FTL' fruit displayed higher soluble solids and sugar content at various development stages. Metabolomic analysis indicated increased sorbitol in 'FTL', linked to elevated sorbitol-6-phosphate-dehydrogenase (S6PDH) activity. Transcriptome analysis identified a key gene for sorbitol synthesis, PsS6PDH4, which was significantly higher expressed in 'FTL' than in 'SYL'. The function of the PsS6PDH4 gene was verified in strawberry, apple, and plum fruits using transient overexpression and virus-induced gene silencing techniques. The results showed that overexpression of the PsS6PDH4 gene in strawberry, apple, and plum fruits promoted the accumulation of soluble solids content and sorbitol, while inhibition of the gene reduced soluble solids content and sorbitol content. Meanwhile, analysis of the relationship between PsS6PDH4 gene expression, sorbitol, and soluble solids content in four different plum varieties revealed a significant correlation between PsS6PDH4 gene expression and soluble solids content as well as sorbitol content. This research discovered PsS6PDH4 as a crucial regulator of sugar metabolism in plum, with potential applications in improving fruit sweetness and nutritional value in various fruit species. Understanding these molecular pathways can lead to innovative approaches for enhancing fruit quality, benefiting sustainable agriculture and consumer preferences in the global fruit industry.