Recently, DNA methylation was proposed to regulate fleshy fruit ripening. Fleshy fruits can be distinguished by their ripening process as climacteric fruits, such as tomatoes, or non-climacteric ...fruits, such as strawberries. Tomatoes undergo a global decrease in DNA methylation during ripening, due to increased expression of a DNA demethylase gene. The dynamics and biological relevance of DNA methylation during the ripening of non-climacteric fruits are unknown.
Here, we generate single-base resolution maps of the DNA methylome in immature and ripe strawberry. We observe an overall loss of DNA methylation during strawberry fruit ripening. Thus, ripening-induced DNA hypomethylation occurs not only in climacteric fruit, but also in non-climacteric fruit. Application of a DNA methylation inhibitor causes an early ripening phenotype, suggesting that DNA hypomethylation is important for strawberry fruit ripening. The mechanisms underlying DNA hypomethylation during the ripening of tomato and strawberry are distinct. Unlike in tomatoes, DNA demethylase genes are not upregulated during the ripening of strawberries. Instead, genes involved in RNA-directed DNA methylation are downregulated during strawberry ripening. Further, ripening-induced DNA hypomethylation is associated with decreased siRNA levels, consistent with reduced RdDM activity. Therefore, we propose that a downregulation of RdDM contributes to DNA hypomethylation during strawberry ripening.
Our findings provide new insight into the DNA methylation dynamics during the ripening of non-climacteric fruit and suggest a novel function of RdDM in regulating an important process in plant development.
This work characterized the role of the R2R3-MYB10 transcription factor (TF) in strawberry fruit ripening. The expression of this TF takes place mainly in the fruit receptacle and is repressed by ...auxins and activated by abscisic acid (ABA), in parallel to the ripening process. Anthocyanin was not produced when FaMYB10 expression was transiently silenced in fruit receptacles. An increase in FaMYB10 expression was observed in water-stressed fruits, which was accompanied by an increase in both ABA and anthocyanin content. High-throughput transcriptomic analyses performed in fruits with downregulated FaMYB10 expression indicated that this TF regulates the expression of most of the Early-regulated Biosynthesis Genes (EBGs) and the Late-regulated Biosynthesis Genes (LBGs) genes involved in anthocyanin production in ripened fruit receptacles. Besides, the expression of FaMYB10 was not regulated by FaMYB1 and vice versa. Taken together, all these data clearly indicate that the Fragaria × ananassa MYB10 TF plays a general regulatory role in the flavonoid/phenylpropanoid pathway during the ripening of strawberry
•The LBL electrostatic deposition maintained strawberry firmness and volatile aroma.•The LBL coating inhibited some primary metabolism in strawberry.•Special secondary metabolites in LBL coated ...strawberry were reduced after storage.
Postharvest strawberries (Fragaria × ananassa Duch.) were coated either by the layer-by-layer (LBL) electrostatic deposition, based on chitosan and carboxymethyl cellulose (CMC), or coated by 1% chitosan. Results suggested that LBL edible coating was significantly effective at inhibiting the loss of fruit firmness and aroma volatiles of strawberry, with little effect on the total soluble solids and total acidity contents. Through an untargeted metabolomic analysis, we found that the LBL application significantly reduced the primary metabolite contents involved in carbohydrate, fatty acids and amino acids metabolism, as well as the secondary metabolite contents involved in terpenoid, carotenoid, phenylpropanoid and flavonoid metabolism after storage. Our results indicated that the LBL edible coating could be potential to maintain strawberry quality with lower metabolites contents after eight days of storage.
Strawberry, raspberry, blueberry, and blackberry by-products were analyzed for proximate composition, bioactive compounds, antimicrobial activity, and fermentability by 13 potential probiotic ...strains. Proximate composition was assessed using AOAC methods and gas chromatography, individual phenolic compounds were quantified through UHPLC-PDA, and antimicrobial activity was determined using the broth microdilution technique. Berry bagasses were then added as carbon source in growth media, being alternatively washed to remove simple sugars, to evaluate the effect of the bagasse on microbial growth and enzymatic production through the API ZYM kit. Glucose and fructose levels ranged from 8.9 to 24.3 g/100 g dry weight, with minor amounts of sucrose and myo-inositol. Eighteen phenolics were quantified, with high amounts of ferulic acid, 4-hydroxybenzoic acid, cyanidin 3-glucoside, and petunidin 3-glucoside. Blackberry bagasse showed the highest pathogen inhibition (71.6–96.5%). Lacticaseibacillus rhamnosus GG and Lentilactobacillus kefiri BIOTEC014 succeeded on media with strawberry or blueberry bagasse as carbon source. The washing of strawberry and blueberry bagasses reduced growth (47–78%) but enhanced enzymatic activity, particularly β-glucosidase in BIOTEC014. These findings suggest that berry bagasses can serve as valuable functional ingredients for food and pharmaceutical applications.
•Berry bagasses have diverse profile of phenolic acids, flavonoids and anthocyanins.•Blackberry and blueberry bagasse extracts show the highest antimicrobial activity.•L. rhamnosus GG and L. kefiri BIOTEC014 thrived on strawberry/blueberry bagasses.•Washing berry bagasses reduces microbial growth but enhances enzymatic activity.•Enzymatic profiles of GG and BIOTEC014 show adaptability to berry substrates.
•Developed a strawberry harvesting robot with a cable-driven gripper.•The gripper is robust to the localisation errors introduced by the vision module.•The subsystems have been integrated into a ...complete system.•The system has been evaluated in the farm and the failure cases have been analysed.•The picking cycle time is 7.49 s with a success rate of 53.57% in the farm setting.
This paper presents the development and evaluation of a robot for harvesting strawberries (Fragaria × ananassa) grown on table-tops in polytunnels. The robot is comprised of a newly-designed gripper mounted on an industrial arm which in turn is mounted on a mobile base along with an RGB-D camera. The novel cable-driven gripper can open fingers to “swallow” a target. Since it is designed to target the fruit not the stem, it just requires the fruit location for picking. Moreover, equipped with internal sensors, the gripper can sense and correct for positional errors, and is robust to the localisation errors introduced by the vision module. Another important feature of the gripper is the internal container that is used to collect berries during picking. Since the manipulator does not need to go back and forth between each berry and a separate punnet, picking time is reduced significantly. The vision system uses colour thresholding combined with screening of the object area and the depth range to select ripe and reachable strawberries, which is fast for processing. These components are integrated into a complete system whose performance is analysed starting with the four main failure cases of the vision system: undetected, duplicate detections, inaccurate localisation and segmentation failure. The integration enables the robot to harvest continuously by moving the platform with a joystick. Field experiments show the average cycle time of continuous single strawberry picking is 7.5 s and 10.6 s when including all procedures. Furthermore, the robot is able to pick isolated strawberries with a close-to-perfect success rate (96.8%). However, in farm settings, the average picking success rate is 53.6%, and 59.0% when including “success with damage”, testing on the strawberry cultivar of “FAVORI”. The failure cases are analysed and most failures are found when picking strawberries in clusters, in which both the detection algorithm and the gripper struggles to separate the berries.
Edible coatings, formulated with sodium alginate and various strains of lactic acid bacteria, were evaluated for their effectiveness in extending the shelf life and mitigating microbial risks ...associated with strawberries. This study specifically employed strains of Lacticaseibacillus paracasei, Lacticaseibacillus rhamnosus, and Lacticaseibacillus plantarum as antimicrobial agents. Through physicochemical property analysis, the alginate-based antimicrobial coating proved most effective in reducing the strawberry weight loss rate, decay index, and ascorbic acid degradation. Over time, all treatments exhibited increased fungal growth. However, strawberries treated with alginate and lactic acid bacteria recorded lower final colony formation counts—6.82 log CFU/g for SA + LPC, 6.04 log CFU/g for SA + LGG, and 6.26 log CFU/g for SA + LP—compared to 8.73 log CFU/g in the control group. In terms of bacterial resistance under gastrointestinal conditions, L. paracasei demonstrated the highest survival rate post-simulated gastric fluid exposure, while L. plantarum showed the greatest resilience post-simulated intestinal fluid exposure. These findings underscore the efficacy of alginate-based antimicrobial coatings in not only enhancing the storage quality of strawberries but also ensuring microbial safety and potential benefits for gut health.
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•Different lactic acid bacteria were introduced into alginate-based edible coatings.•The coating significantly optimized the physicochemical properties of strawberries.•The bacteriostasis against molds and yeasts caused by strawberry rot was verified.•The coating showed effective decontamination of external pathogens.•Coating probiotics behaved promising tolerability of gastrointestinal conditions.
Understanding how strawberry (Fragaria x ananassa) nutritional and quality traits are genetically regulated and correlated is an essential step towards improving marker-assisted breeding programmes ...in this crop. A first step to achieve this goal was to construct a single nucleotide polymorphism (SNP)-based genetic map of 140 F
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individuals of a cross between the 2 octoploid parents 'Redgauntlet' and 'Hapil'. The map consisted of 3933 SNPs distributed over 28 linkage groups, representing the 7 homoeologous groups expected in Fragaria (2n = 8x = 56), and covered a total length of 2624.7 cM with an average resolution of 0.7 cM/SNP. Two overlapping subsets of F
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individuals were evaluated in the field and glasshouse at East Malling Research and the University of Reading, respectively. Negative correlation was observed between Pelargonidin and the three traits L*, a*, and b*, whereas positive correlations were observed within L*, a*, and b*, and between Ellagic acid, Pelargonidin, and Cyanidin at both trial locations. Quantitative trait loci (QTL) mapping revealed 29 significant QTL associated with the measured traits and mapped over 16 linkage groups. Two QTL for fruit fresh weight were co-located between day 1 and day 4 of shelf life, accounting for over 62% of the variation. These data will enhance our understanding of the genetic basis and correlation of strawberry quality traits and provide the basis for refining QTL that underpin the genetic regulation of these quality traits.
This study describes the synthesis of Chitosan - corn protein (CSZ-TG) composites using TG enzyme (TG) as a cross-linking agent and the preparation of chitosan-based composite membrane material ...(CSZEO-TG) by blending citrus essential oil (EO) with the synthesized CSZ-TG. The prepared composite membrane material was used for fresh strawberry preservation and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-spectral diffraction, tensile properties, and water vapor and CO2 permeability. Scanning electron microscopy results showed a smooth surface of the composite membrane material after the addition of TG enzyme, while Fourier transforms infrared spectroscopy results showed a structural change of the composite membrane material after the addition of corn protein (Z). The tensile results showed an increase in the tensile strength of the composite membrane material after the addition of TG enzyme, while the flexibility of the composite membrane material was enhanced after the addition of EO. Compared with the pure chitosan membrane (CS), the water vapor and CO2 barrier properties of the composite membrane material after the addition of Z, TG, and EO did not change much, and they all showed better water vapor barrier properties. The results of the antioxidant analysis of the solution of the CSZEO-TG composite membrane material showed that the composite membrane material had efficient antioxidant properties. The effects of the composite film material on the storage period and quality of strawberries were evaluated by the indicators of weight loss, hardness, decay rate, soluble solids, titratable acid content, MDA content, and the content of four enzymes, SOD, POD, PPO and CAT. Comprehensive freshness data analysis showed that CSZEO-TG had the best freshness preservation performance and effectively extended the shelf life of strawberries.
•CaCl2 combined nano-chitosan (CaCl2-NCTS) film positively affected the postharvest quality of strawberries.•Preservation effect of CaCl2-NCTS film was better than NCTS film.•CaCl2-NCTS film coating ...suppressed Malondialdehyde production.•A smooth surface of strawberries coated with 3 % CaCl2 + 0.2 % nano-chitoan was observed.
This study aimed to investigate influences of calcium chloride (CaCl2) concentrations combined with nano-chitosan coating on the quality of strawberry during postharvest storage. The fruit were dipped in different concentrations of calcium chloride (1 %, 2 %, 3 %, 4 %) before being coated with 0.2 % nano-chitosan. Physico-chemical analysis including the overall quality index, weight loss, firmness, titratable acidity, total soluble solid, l-ascorbic acid content, antioxidant capacity, total phenolic content, total anthocyanin content, and malondialdehyde content were performed in 3 d intervals until fruit became unmarketable. Among six examined treatments, a combination of 3 % CaCl2 and nano-chitosan (NCTS) was the most effective one as maintaining the highest score of overall quality index of strawberry stored at 4 °C up to 15 d. The treatment also significantly reduced weight loss, preserved l-ascorbic acid, total anthocyanin contents, antioxidant capacity, and retarded malondialdehyde production. The scanning electron microscope image showed a smooth surface of strawberries coated with 3 % CaCl2 combined 0.2 % nano-chitosan. There has no bitterness detected in the treated strawberries after being stored 15 d at 4 °C. The major volatile compounds determined in the initial day were remained until the 15th d of storage.
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