Search

In this work, we present biocompatible nanocarriers based on modified polysaccharides capable of transporting insulin macromolecules through human skin without any auxiliary techniques.

This paper reports one-step synthesis of polysaccharide-based nanovehicles, capable of transporting ionic zinc via plant cuticle without auxiliary stimulation. Delivery of highly hydrophilic nutritive microelements via the hydrophobic cuticle of plant foliage is one of the major challenges in modern agriculture. In traditional nutrition via roots, up to 80% of microelements permeate to soil and get wasted; therefore, foliar treatment is an environmentally and economically preferable alternative. Carboxymethyl cellulose (CMC) was modified to amphiphilic N-octylamide-derivative (CMC-8), which spontaneously self-assemble to nanovehicles. It was found that hydrophobic substituents endow a biopolymer with unexpected affinity toward a hydrophilic payload. CMC-8 nanovehicles effectively encapsulated ionic zinc (ZnSO4) and delivered it upon foliar application to pepper (Capsicum annuum) and tomato (Solanum lycopersicum) plants. Zinc uptake and translocation in plants were monitored by SEM-EDS and fluorescence microscopic methods. In planta monitoring of the carrier was done by labeling nanovehicles with fluorescent carbon dots. Three-dimensional (3-D) structural modeling and conformational dynamics explained the CMC-8 self-assembly mechanism and zinc coordination phenomenon upon introduction of hydrophobic substituents.

This study presents antibiofilm coating formulations based on Pickering emulsion templating. The coating contains no bioactive material because its antibiofilm properties stem from passive mechanisms that derive solely from the superhydrophobic nature of the coating. Moreover, unlike most of the superhydrophobic formulations, our system is fluorine-free, thus making the method eminently suitable for food and medical applications. The coating formulation is based on water in toluene or xylene emulsions that are stabilized using commercial hydrophobic silica, with polydimethylsiloxane (PDMS) dissolved in toluene or xylene. The structure of the emulsions and their stability was characterized by confocal microscopy and cryogenic-scanning electron microscopy (cryo-SEM). The most stable emulsions are applied on polypropylene (PP) surfaces and dried in an oven to form PDMS/silica coatings in a process called emulsion templating. The structure of the resulting coatings was investigated by atomic force microscopy (AFM) and SEM. The surface of the coatings shows a honeycomb-like structure that exhibits a combination of micron-scale and nanoscale roughness, which endows it with its superhydrophobic properties. After tuning, the superhydrophobic properties of the coatings demonstrated highly efficient passive antibiofilm activity. In vitro antibiofilm trials with E. coli indicate that the coatings reduced the biofilm accumulation by 83% in the xylene-water-based surfaces and by 59% in the case of toluene-water-based surfaces.

Cannabis sativa L. is used to treat a wide variety of medical conditions, in light of its beneficial pharmacological properties of its cannabinoids and terpenes. At present, the quantitative chemical analysis of these active compounds is achieved through the use of laborious, expensive, and time-consuming technologies, such as high-pressure liquid-chromatography- photodiode arrays, mass spectrometer detectors (HPLC-PDA or MS), or gas chromatography-mass spectroscopy (GC-MS). Hence, we aimed to develop a simple, accurate, fast, and cheap technique for the quantification of major cannabinoids and terpenes using Fourier transform near infra-red spectroscopy (FT-NIRS). FT-NIRS was coupled with multivariate classification and regression models, namely partial least square-discriminant analysis (PLS-DA) and partial least squares regression (PLS-R) models. The PLS-DA model yielded an absolute major class separation (high-THC, high-CBD, hybrid, and high-CBG) and perfect class prediction. Using only three latent variables (LVs), the cross-validation and prediction model errors indicated a low probability of over-fitting the data. In addition, the PLS-DA model enabled the classification of chemovars with genetic-chemical similarities. The classification of high-THCA chemovars was more sensitive and more specific than the classifications of the remaining chemovars. The prediction of cannabinoid and terpene concentrations by PLS-R yielded 11 robust models with high predictive capabilities (R

The pericarp is the predominant tissue determining the structural characteristics of most fruits. However, the molecular and genetic mechanisms controlling pericarp development remain only partially understood. Previous studies have identified that CLASS-II KNOX genes regulate fruit size, shape, and maturation inArabidopsis thalianaandSolanum lycopersicum. Here we characterized the roles of theSolanum lycopersicumCLASS-II KNOX (TKN-II) genes in pericarp development via a detailed histological, anatomical, and karyotype analysis of theTKN-IIknockdown (35S:amiR-TKN-II) fruits. We identify that35S:amiR-TKN-IIpericarps contain more cells around their equatorial perimeter and fewer cell layers than the control. In addition, the cell sizes but not the ploidy levels of these pericarps were dramatically reduced.Further, we demonstrate that fruit shape and pericarp layer number phenotypes of the35S:amiR-TKN-IIfruits can be overridden by theproceramutant, known to induce a constitutive response to the plant hormone gibberellin. However, neither theproceramutation nor exogenous gibberellin application can fully rescue the reduced pericarp width and cell size phenotype of35S:amiR-TKN-IIpericarps. Our findings establish that TKN-II genes regulate tomato fruit anatomy, acting via gibberellin to control fruit shape but utilizing a gibberellin-independent pathway to control the size of pericarp cells.HighlightTomatoCLASS-II KNOXgenes regulate fruit and pericarp anatomy via GA-dependent and independent pathways.

The pericarp is the predominant tissue determining the structural characteristics of most fruits. However, the molecular and genetic mechanisms controlling pericarp development remain only partially understood. Previous studies have identified that CLASS-II KNOX genes regulate fruit size, shape, and maturation in Arabidopsis thaliana and Solanum lycopersicum. Here we characterized the roles of the S. lycopersicum CLASS-II KNOX (TKN-II) genes in pericarp development via a detailed histological, anatomical, and karyotypical analysis of TKN-II gene clade mRNA-knockdown (35S:amiR-TKN-II) fruits. We identify that 35S:amiR-TKN-II pericarps contain more cells around their equatorial perimeter and fewer cell layers than the control. In addition, the cell sizes but not the ploidy levels of these pericarps were dramatically reduced. Further, we demonstrate that fruit shape and pericarp layer number phenotypes of the 35S:amiR-TKN-II fruits can be overridden by the procera mutant, known to induce a constitutive response to the plant hormone gibberellin. However, neither the procera mutation nor exogenous gibberellin application can fully rescue the reduced pericarp width and cell size phenotype of 35S:amiR-TKN-II pericarps. Our findings establish that TKN-II genes regulate tomato fruit anatomy, acting via gibberellin to control fruit shape but utilizing a gibberellin-independent pathway to control the size of pericarp cells.

Fruits can be divided into dry and fleshy types. Dry fruits mature through senescence and fleshy fruits through ripening. Previous studies have indicated that partially common molecular networks could govern fruit maturation in these different fruit types. However, the nature of such networks remains obscure. CLASS-II KNOX genes were shown to regulate the senescence of the Arabidopsis (Arabidopsis thaliana) dry fruits, the siliques, but their roles in fleshy-fruit development are unknown. Here, we investigated the roles of the tomato (Solanum lycopersicum) CLASS-II KNOX (TKN-II) genes in fleshy fruit ripening using knockout alleles of individual genes and an artificial microRNA line (35S:amiR-TKN-II) simultaneously targeting all genes. 35S:amiR-TKN-II plants, as well as a subset of tkn-II single and double mutants, have smaller fruits. Strikingly, the 35S:amiR-TKN-II and tknII3 tknII7/+ fruits showed early ripening of the locular domain while their pericarp ripening was stalled. Further examination of the ripening marker-gene RIPENING INHIBITOR (RIN) expression and 35S:amiR-TKN-II rin-1 mutant fruits suggested that TKN-II genes arrest RIN activity at the locular domain and promote it in the pericarp. These findings imply that CLASS-II KNOX genes redundantly coordinate maturation in both dry and fleshy fruits. In tomato, these genes also control spatial patterns of fruit ripening, utilizing differential regulation of RIN activity at different fruit domains.

This paper reports one-step synthesis of polysaccharide-based nanovehicles, capable of transporting ionic zinc

Ripening is a complex developmental change of a mature organ, the fruit. In plants like a tomato, it involves softening, pigmentation, and biosynthesis of metabolites beneficial for the human diet. Examination of the transcriptional changes towards ripening suggests that redundant uncharacterized factors may be involved in the coordination of the ripening switch. Previous studies have demonstrated that Arabidopsis CLASS-II KNOX genes play a significant role in controlling the maturation of siliques and their transition to senescence. Here we examined the combined role of all four tomato CLASS-II KNOX genes in the maturation and ripening of fleshy fruits using an artificial microRNA targeting them simultaneously. As expected, the knockdown plants (35S::amiR-TKN-CL-II) exhibited leaves with increased complexity, reminiscent of the leaf phenotype of plants overexpressing CLASS-I KNOX, which antagonize CLASS-II KNOX gene functions. The fruits of 35S::amiR-TKN-CL-II plants were notably smaller than the control. While their internal gel/placenta tissue softened and accumulated the typical pigmentation, the pericarp color break took place ten days later than control, and eventually, it turned yellow instead of red.Additionally, the pericarp of 35S::amiR-TKN-CL-II fruits remained significantly firmer than control even after three weeks of shelf storage. Strikingly, the 35S::amiR-TKN-CL-II fruits showed early ethylene release and respiration peak, but these were correlated only with liquefaction and pigmentation of the internal tissues. Our findings suggest that CLASS-II KNOX genes are required to coordinate the spatial and temporal patterns of tomato fruit ripening.One sentence summaryTomato CLASS-II KNOX genes play antagonistic roles in the regulation of ripening at the internal fruit domains and pericarp.

Quercetin-chitosan (QCS) polysaccharide was synthesized via non-radical reaction using L-valine-quercetin as the precursor. QCS was systematically characterized and demonstrated amphiphilic properties with self-assembling ability. In-vitro activity studies confirmed that quercetin grafting does not diminish but rather increases antimicrobial activity of the original chitosan (CS) and provided the modified polysaccharide with antioxidative properties. QCS applied as a coating on fresh-cut fruit reduced microbial spoilage and oxidative browning of coated melon and apple, respectively. Notably, QCS-based coatings prevented moisture loss, a major problem with fresh produce (2%, 12% and 18% moisture loss for the QCS-coated, CS-coated and uncoated fruit, respectively). The prepared QCS polysaccharide provides advanced bioactivity and does not involve radical reactions during its synthesis, therefore, it has good potential for use as a nature-sourced biocompatible active material for foods and other safety-sensitive applications.

This work evaluated the efficacies of different coatings: chitosan, gelatin and chitosan-gelatin applied layer-by-layer (LbL), for maintaining the quality of sweet peppers that were stored for 3 weeks at a sub-optimal temperature (1.5 °C) and at an optimal storage temperature (7 °C). After the cold-storage period, fruits were kept under marketing conditions (21 °C) for 3 more days. An edible chitosan coating (2%) effectively alleviated chilling injury and the incidence of decay, and also preserved the nutritional quality of sweet peppers that were kept for 3 weeks at 1.5 °C plus 3 more days at 21 °C. The chitosan coating was more effective than the two other coatings. All three coating treatments significantly reduced external CO2 production, as compared to uncoated control fruit. Storage temperatures did not significantly affect external CO2 production, although CO2 production was slightly higher at 1.5 °C. The chitosan coating exhibited good CO2 gas permeability properties and the peppers coated with that material had lower respiration rates than those in the other two experimental treatments or the control. From a practical point of view, chitosan coating could replace the plastic bags previously found to alleviate chilling injury in peppers that are stored at 1.5 °C as a quarantine treatment.

Improved postharvest storage is a major target for pepper-crop production. The three main components of postharvest improvement of pepper fruit are reducing water-loss rate, reducing chilling susceptibility, and increasing resistance to pathogens. To date, a small number of Quantitative Trait Locus (QTL) studies have been reported for reduced water loss and enhanced tolerance to chilling and anthracnose. More effort is needed to screen germplasm collections for accessions with improved postharvest traits. Molecular studies have enabled the identification of candidate genes conferring reduced susceptibility to chilling injury and pathogen infection in pepper fruit, and in related crops such as tomato - which may be implemented in pepper. Manipulation of the activity of these genes by genome editing can improve postharvest pepper quality.

A series of quaternary dimethyl-(alkyl)-ammonium chitosan derivatives (QACs) was synthesized and studied for physicochemical properties and bioactivity. The QACs tended to spontaneously self-assembly into nanoaggregates. Antimicrobial activity was examined in vitro on Gram-negative Escherichia coli (E. coli) and Gram-positive Listeria innocua (L. innocua) bacteria as well as phytopathogenic fungus Botrytis cinerea. The hexyl chain-substituted QAC-6 demonstrated the highest potency causing 3.0- and 4.5-log CFU mL-1 reduction of E. coli and L. innocua, respectively. QAC-6 was tested for antimicrobial activity on stainless steel coupons and fresh spinach leaves. A traditional 'wet' application (spray) and dry Engineered Water Nanostructure (EWNS) approach were used for spinach decontamination. With both approaches, significant reduction of microbial load on the treated produce was achieved. The wet application showed a greater reduction of microbial load, while the advantages of EWNS were reaching the antimicrobial effect with miniscule dose of active agent leaving treated surface visibly dry.

This study examined the effects of stem-pruning and fruit-thinning on the yield of marketable watermelon fruit (&gt, 5 kg) and watermelon quality after four days of postharvest storage at 22 &deg, C (marketing simulation). We examined the fruits from non-grafted and grafted plants (TZ and Nurit rootstocks) for two consecutive years. Grafting increased the number of marketable fruit per m2. The weight of the average marketable fruit was increased by pruning, but was not affected by thinning or by the choice of rootstock. The level of total soluble solids was higher among fruits from Nurit rootstock. Flesh texture was improved by grafting, but was not affected by thinning or pruning. Thinning improved the taste of the fruit significantly better than stem-pruning did. Grafting (both rootstocks) was associated with crispier fruits. The fruits from Nurit-grafted plants tasted best. The combination of grafting + fruit-thinning increased the fruit lycopene content. The highest levels of vitamin C were found among the fruit from Nurit-grafted plants and the pruned + Nurit-grafted plants, in particular. Overall, fruit quality was affected mainly by grafting onto Nurit rootstock in combination with fruit-thinning and less by stem-pruning. However, not all internal and nutritional quality parameters were significantly affected by the grafting + fruit-thinning treatment.

Yellow sweet peppers (Capsicum annuum L. cv. Dinamo) are generally more susceptible than red sweet peppers to physiological and pathological deterioration after harvest. Yellow peppers also fetch higher prices at market. In this study, we examined the external and nutritional quality attributes of yellow pepper fruits stored at suboptimal temperatures of 1.5 and 4 &deg, C for 3 weeks, followed by a 3-day shelf-life simulation. Notably, yellow peppers kept in plastic (Xtend&reg, Stepac, Tefen, Israel) bags at 4 &deg, C maintained their external quality just as well as peppers stored at the optimum temperature of 7 &deg, C. In addition, nutrient content (namely ascorbic acid) and total phenolic and hydrophilic antioxidant contents were not reduced when the peppers were kept at suboptimal storage temperatures of 4 or 1.5 &deg, C in Xtend&reg, plastic packaging. Thus, the external and nutritional qualities of yellow pepper fruits can be preserved at suboptimal temperatures of 4 &deg, C with Xtend&reg, plastic packaging. This is particularly significant in light of the fact that storage at such temperatures is sometimes used as a quarantine method to eliminate pests on produce imported into Israel.

Interaction of grafting and shading on tomato physical properties and chemical composition after 15 days of storage at 10 &deg, C and 90% relative humidity was investigated in ungrafted and grafted tomato cultivars &lsquo, Optima F1&rsquo, and &lsquo, Big beef F1&rsquo, grown under shading nets (red and pearl net) and nonshaded conditions. For grafted plants &lsquo, Maxifort&rsquo, rootstock was used. The effects of two weeks of storage was statistically significant when taking into account the effects of grafting, shading and variety for all tomato fruit composition parameters, except total phenols. A principal component analysis demonstrated that the changes in tomato fruit traits during the studied storage period were the main source of differentiation in tomato fruit quality. Beside a slight loss of firmness, tomato fruits were generally expected to have lower lycopene, sugar, malic and citric acid contents, higher succinic acid content, more elastic fruit skin and higher ascorbic acid content. Additionally, after storage, fruits from grafted plants had lower total phenol, higher ascorbic acid and higher succinic acid contents compared to fruits from ungrafted plants. Storage diminishes the differences in quality achieved through convenient grafting and shading combinations.

Cabbage production is problematic in hot climates, since it grows best in a temperature range of 16–18 °C. In Israel the best production time is fall and winter, but to allow for year round supply cultivation and storage is necessary in the spring and summer months. Three cabbage cultivars, Cheers, Fresco and Pruktor, were examined for their ability to be grown in the spring and stored over the summer. Experiments were conducted over four seasons. Storage was in both regular air and controlled atmosphere at 1 °C, for up to 120 d. Controlled atmosphere was applied by two methods; an experimental system of containers of 400 L, and in a small commercial room of 5 MT. Regular air storage for an extended period was not suitable because all the cultivars developed unacceptable weight loss, yellowing, decay and physiological disorders (black spot and grey rib) when stored for more than one month. CA enabled storage of Cheers and Pruktor for up to three months. Fresco developed high levels of black spot under both regular and controlled atmosphere storage. Cheers had higher levels of isothiocyanates and less physiological disorders than Pruktor. Cheers was found to be the best cabbage cultivar for spring production and storage over the summer. The CA conditions of 2% O2 and 5% CO2 were better than 3% O2, 6% CO2.

Summary Quality of produce cannot be improved after harvest, only maintained. Postharvest handling depends on the specific conditions of production, season, method of handling, and distance to market. Under organic production, growers harvest and market their produce at or near the peak ripeness more commonly than in many conventional systems. Organic production often includes more specialty varieties whose shelf life and shipping traits are reduced or even inherently poor. Harvesting and handling techniques that minimize injury to the commodity, as well as increased care with field and packinghouse sanitation, (chlorine, ozone, calcium hypochlorite, sodium hypochlorite and chlorine dioxide, acetic acid, peroxyacetic acid, vinegar, ethyl alcohol, hydrogen peroxide, etc.) during postharvest processes are vital components of a postharvest management plan for organic products. Sodium carbonate, sodium bicarbonate, and physical treatments such as heat treatments (as hot water treatment or dips, short hot water rinsing and brushing or hot air) can significantly lower the disease pressure on the harvested commodities. These sanitation practices are very easy to implement in the organic food production chain. They start in the field and continue during harvesting, sorting, packing, and transportation and continue even in the consumer’s home. All those treatments reduce rot development, provide quarantine security, and preserve fruit quality during cold storage and shelf life. In addition, the use chitosan, propolis, methyl jasmonate, essential oils, carnuba wax, biocontrol agents and modified atmosphere packaging can also reduce decay development during prolonged storage. All these treatments can be applied alone or in combination with each other in order to improve decay control after harvest and provide a healthy and safe product to the consumer. The aim of this chapter is to shed more light on the latest information on permitted treatments for organic products and on the possible mode-of-action of these treatments. This chapter summarizes technologies developed over the past five years that explore special physical treatments applied either directly, or in combination with other means to control rot development and insect infestation on fresh produce.

Modification of spectral quality via coloured shade nets can act as a physiological tool to modify the crop microenvironment and advance plant growth and yield. This literature review presents data on the physiological responses in vegetables linked to light quality under different coloured shade nets. The physiological parameters discussed in the review include: vegetable growth parameters (leaf area, leaf chlorophyll), tissue structure, fruit ripening, physiological disorders, pest and disease incidence, fruit quality parameters (soluble solids content and titratable acidity), phytochemicals (antioxidant activity, ascorbic acid, carotenoid and flavonoid contents) and aroma volatile compounds at harvest. Also, it is evident in the reviewed literature that light quality influences the biosynthesis, accumulation and retention of vegetable phytochemicals, as well as the decay development during storage. These new strategies to modulate light quality should be conveyed to vegetable producing farmers, thus allowing them to preserve the freshness and post-harvest quality of vegetables for an extended period of time, and to meet the consumers demand for vegetables with high nutritional value all year round. Research on light manipulation in horticultural systems is necessary for a sustainable and market-oriented open field and greenhouse vegetable production in the future.

High resolution QTL mapping of genetic factors affecting fruit quality traits in melon (Cucumis melo) was achieved in two projects. Next-generation sequencing (NGS), coupled with unique genetic materials, was used to attain high resolution mapping, in both studies. The first project was based on the RNA-seq of mature fruits of a Recombinant Inbred Lines (RIL) population derived from a cross between PI 414723 and 'Dulce'. The second project was based on genotyping-by-sequencing (GBS) analyses of F3 plants derived from a cross between 'Noy Amid' and 'Dulce'. In each project, QTL analysis was conducted using approximately 60,000 SNP markers that were detected by either GBS or RNA-seq. In the first project, phenotyping and metabolic profiling included fruit quality traits associated with taste, aroma and color while the second project focused on flesh and rind color, ethylene and the formation of the fruit abscission zone. Evidence of the high resolution of the analysis was provided in cases where QTLs for selected fruit traits were mapped to an interval of 1- 20 genes that included the known underlying causative genes. These cases included genes associated with the accumulation of specific aroma volatiles and fruit fleshcolor.

Grafting of vegetable seedlings is a unique horticultural technology, practiced for more than five decades, aiming to overcome problems associated with intensive cultivation on limited arable land. Grafting can protect vegetables against soil-borne diseases and nematodes; against abiotic stresses such as high or low temperatures, salinity, drought or excessive soil-water content; and against elevated soil concentrations of heavy metals and organic pollutants. Watermelon is one of the most popular vegetables to be grafted, and more than 90% of the plants worldwide are commercially grafted. This mini review aims to summarize the latest available information about the effects of rootstock/scion combinations with respect to enhancing or impairing watermelon fruit-quality. A better understand of the influence of rootstock/scion compatibility or incompatibility on fruit-quality parameters will facilitate decision-making by growers and direct breeding programs to produce high-quality grafted fruits in a cost-effective manner. © 2020 Society of Chemical Industry.