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The storage of zucchini fruit at low temperatures during postharvest induces a physiological disorder called chilling injury that drastically reduces fruit quality and shelf life. The phytohormone abscisic acid (ABA) is involved in the acquisition of cold tolerance in zucchini fruit, being the riboflavin pathway one of the most differentially induced with ABA treatment. Thus, the aim of this work was to elucidate the involvement of riboflavin in quality maintenance of zucchini fruit during postharvest cold storage. After testing different concentrations of exogenous riboflavin, 0.5 mM showed the best results. Riboflavin treatment reduced H 2 O 2 content, but the enzymatic antioxidant defense did not change significantly. This response is due to a rise of non-enzymatic antioxidant defense, by accumulating metabolites like ascorbate and carotenoids, as well as inducing phenolic metabolism. The application of this vitamin enhanced the phenolic and flavonoid content in fruit, concomitant with an induction of PAL and C4H activities and an inhibition of PPO activity. This enhancement of the phenylpropanoid pathway resulted in high vanillic acid and quercetin levels at first day of cold storage. The induction of numerous antioxidant compounds and abscisic acid by riboflavin treatment at short-term postharvest period could be responsible for the lack of chilling injuries in zucchini fruit. Therefore, riboflavin could be successfully implemented in the food industry as an alternative to physical or chemical treatments, due to it is an innocuous additive with good water solubility and low cost, as it prolongs the shelf-life of zucchini fruit and increases its nutraceutical properties. [Display omitted] • Exogenous riboflavin improves cold tolerance in zucchini fruit. • 0.5 mM is the most appropriate dose for increasing shelf-life of commodities. • Riboflavin enhances non-enzymatic antioxidant diminishing chilling injury. • Phenolic metabolism is induced by riboflavin treatment at short-term storage. • Riboflavin treatment maintains ABA content during postharvest period. [ABSTRACT FROM AUTHOR]

Melon grafting represent an increasingly important strategy against biotic and abiotic stresses. Cucurbita hybrid rootstocks have been extensively developed for this purpose, but it is necessary to find new alternatives. In this work, several experimental rootstocks of cultivated and wild resources from the Cucurbita and Cucumis genera have been evaluated using Piel de Sapo melon as scion. Cucurbita rootstocks tended to increase fruit size and seed cavity and offered more rounded shapes at the early stages of ripening, but this effect was later minimised. Cucumis rootstocks tended to show less vigour than those of Cucurbita. C. metuliferus hybrid rootstock caused plant collapse at specific environmental conditions, probably due to differences in the growth of rootstock and scion. One of the Cucurbita maxima x C. moschata and the Cucurbita pepo experimental hybrids were also less vigorous, delaying flowering and fruit set, and compromising yield. The effects of Cucurbita and Cucumis rootstocks on sugar and acid accumulation of Piel de Sapo were almost negligible, but they altered the volatile profile. This last impact depended on the specific scion x rootstock interaction and the environmental conditions. Cucumis rootstocks tended to minimise it, especially the hybrid Cucumis melo subsp. melo x C. melo subsp. agrestis Pat 81, which offered a volatile profile highly resembling the non-grafted control. Among Cucurbita alternatives, the commercial hybrid Cucurbita maxima x C moschata had the lowest impact, while other experimental hybrids C. moschata x C. moschata and C. maxima x C. moschata increased levels of alcohols. Among Cucumis rootstocks, the hybrids of wild species Cucumis ficifolius x C. anguria and C. ficifolius x C. myriocarpus , and C. metuliferus had a higher impact on the volatile profile. [Display omitted] • Cucumis rootstocks represent a good alternative to classic Cucurbita hybrids. • Vigorous varieties as Piel de Sapo may collapse when grafted on C. metuliferus. • C. melo melo x C. melo agrestis Pat 81 minimises impact on flavour related metabolites. [ABSTRACT FROM AUTHOR]

Different meta-heuristic optimization algorithms have been used in a variety of fields due to their intelligent behavior and fast convergence. However, use of these algorithms in the engine behavior optimization is very-limited. The development of so-called hybrid optimization technique when these algorithms are combined with experimental design technique is an upcoming method in the field of renewable energy. Hence in this research, meta-heuristic optimization algorithms and experimental design methods were combined to optimize the engine behavior. Additionally, artificial neural networks (ANN) were employed to forecast the performance and emission behaviors of a CI engine running on a novel hybrid biodiesel blend of Cucurbita pepo. L (pumpkin) and Prosopis juliflora , mixed with a novel Elaeocarpus ganitrus (Rudraksha) additive. To assess the success of the ANN, four statistical benchmarks (R2, and MSE) were used. Experiments were designed according to Design of Experiments (DOE) rules with performance and emission parameters as outputs. Response surface methodology (RSM) was employed to find the effect of interaction factors. Single objective and multi-objective optimization using highly efficient hybrid RSM-particle swarm optimization (RPSO) and dragon fly algorithm (RMODA) were employed to optimize the response of the obtained RSM equations. The outcomes demonstrated that RSM and ANN were excellent modelling techniques for these kinds of situations, with good accuracy. In addition, ANN's prediction performance (R2 = 0.978 for BTE) was somewhat better than RSM's (R2 = 0.960 for BTE). On the other hand, the PJB20 blend with 5 mL additive increased BTE by 52.8% and reduced BSFC by 34.9% at maximum load. The smoke opacity was lowered by 7.1% when compared to pure diesel, without any engine modifications. CO 2 emission was seen to be shortened by 19.14%. Finally, it can be concluded that this novel biodiesel can be possibly utilized in CI engines with no modification and the engine characteristics can be controlled by optimization and prediction models. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • UPLC-QqQ-MS and GC–MS was employed for comprehensive metabolomics of pumpkin fruit. • Diverse chemical classes identified including phenolic acids, flavonoids, cucurbitacins. • Pumpkin flesh fraction displayed potent α-glucosidase inhibition. • Strong α-amylase inhibition in pumpkin defatted seed fraction observed. • Key bioactive metabolites vaccenic acid, sinapic acid, and kuguacin G, unveiled. This comprehensive study explores the phytoconstituents of different parts of pumpkin (Cucurbita pepo) including flesh, peel, seeds, pumpkin juice, and pumpkin seed oil. Utilizing advanced analytical techniques including UPLC-QqQ-MS and GC-TSQ-MS combined with multivariate statistical analysis, 94 distinct chromatographic peaks from various chemical classes were annotated. Predominant classes included phenolic acids, flavonoids, cucurbitacins, amino acids, triterpenoids, fatty acids, sterols, carotenoids, and other compounds. For more comprehensive chemical profiling of the tested samples, fractionation of the different parts of the fruit was attempted through successive solvent extraction. The unsaponifiable part of the oils, analyzed by GC, showed that the phytosterols, namely ß-sitosterol, and stigmasterol are in the majority. All pumpkin extracts showed significant inhibition of carbohydrase enzymes and glucose uptake promotion by cells. Pumpkin flesh butanol fraction exhibited potent α-glucosidase inhibition, while pumpkin defatted seed methylene chloride fraction showed strong α-amylase inhibition. Additionally, pumpkin seed oil and defatted seed petroleum ether fraction demonstrated high glucose uptake activity. Bioactive metabolites including vaccenic acid, sinapic acid, kuguacin G, luteolin hexoside, delta-7-avenasterol, cucurbitosides and others were unveiled through OPLS multivariate models elucidating the anti-diabetic potential of pumpkin. These findings support the use of pumpkin as a functional food, offering insights into its mechanisms of action in diabetes management. [ABSTRACT FROM AUTHOR]

The paper studies the lubricant properties of blends of Thevetia peruviana oil (TPO) and Cucurbita pepo L. oil (CPO) prepared at different proportions. The physicochemical properties were determined as per ASTM standard and the anti-wear and extreme pressure tests were performed using four-ball tribotester as per ASTM D4172–94 and ASTM D2783, respectively. The blend of 40% TPO and 60% CPO was found the best blend as per the Entropy-TOPSIS method and further at optimal concentration of 1 wt% of titanium oxide nanoparticles it exhibited the coefficient of friction of 0.0329 ± 0.002 and wear scar diameter of 0.291 ± 0.005 mm. The present study indicates that TPO-CPO blends with optimal additivation can be an alternative biodegradable solution to commercial mineral oils. • The compatibility of Thevetia peruviana oil, Cucurbita pepo L. oil and their blends with commercial oil was studied. • The physicochemical, rheological, and tribological properties of the blends with or without TiO 2 were examined. • Blend B40 was found suitable as per entropy-based TOPSIS method. • Nano-biolubricants exhibited better lubricant properties. • Lubricant mechanism of oil samples was discussed. [ABSTRACT FROM AUTHOR]

Cucurbit leaf crumple virus (CuLCrV) is among the prominent viruses infecting cucurbits in the USA. Attainable procedures of virus inoculation to crops are prerequisite for screening of resistance against the virus. Because mechanical (non-vector-mediated) infection by cucurbit leaf crumple virus (CuLCrV) is inefficient in economically important crops, screening for CuLCrV resistance is currently laborious and time-consuming using transmission by viruliferous whiteflies. We constructed an infectious partial tandem repeat construct of an isolate of CuLCrV from Georgia, USA, in the plant expression binary vector pCambia2300 and transformed it into Agrobacterium tumifaciens strain EHA105. Agroinfiltration of this construct into the abaxial surface of the leaves of common bean (Phaseolus vulgaris L.) produced a systemic infection characteristic of CuLCrV, although this approach was not successful for yellow squash. However, we report a very efficient and reproducible inoculation procedure established in squash when the leaves were injured with a microneedle and rubbed it with cell suspension harbouring the infectious viral construct. [ABSTRACT FROM AUTHOR]

In this study, unconventional technologies were used to enhance the phenolic and antioxidant content of zucchini pieces by enriching them with blueberry juice. Our results indicated that ohmic heating (OH) increased the extraction rates of compounds with antioxidant potential in blueberry juice, mainly at 70 °C for 15 min and 7.8 V cm1. Furthermore, OH applied after vacuum impregnation led to higher retention rates of phenolic compounds and antioxidant capacity in zucchini pieces impregnated with blueberry juice, especially at 70 °C for 30 min and 7.8 V cm‐−1. The impregnation process also promoted the darkening of zucchini pieces (due to anthocyanin retention) and increased soluble solids. After drying by hot air and vacuum microwave, the phenolic content, antioxidant capacity, physicochemical and color characteristics of the impregnated and non-impregnated zucchinis were distinctly altered. However, vacuum microwave drying at 120 and 460 W can be suggested as the most suitable conditions for both zucchini products, as it resulted in high concentrations of individual phenolic compounds (e.g. up to 44.25, 8.15, and 2.56 mg 100 g‐−1 dry weight (DW) for catechin, gallic acid, and cyanidin, respectively), as well as total phenolic content of up to 484.37 mg gallic acid equivalent 100 g1 DW, total flavonoid content of up to 197.69 mg catechin equivalent 100 g‐−1 DW, and total monomeric anthocyanins of up to 9.48 mg cyanidin 3-glucosideo equivalent 100 g‐−1 DW. • Vacuum impregnation (VI) with ohmic heating (OH) favor compounds impregnation. • Hot air and vacuum microwave drying (VMD) affect attributes of non- and enriched zucchini. • Cyanidin and epicatechin from blueberry juice were added to the enriched zucchini. • VMD at 120 and 460 W resulted in lower losses of individual phenolic compounds. [ABSTRACT FROM AUTHOR]

Chilling injury is a physiological disorder that appears when zucchini fruit is stored at low temperatures, causing a severe diminution of the quality and nutraceutical value. Abscisic acid (ABA) has been proven to be a key natural agent preventing low-temperature damage. This work aimed to elucidate the changes in exocarp metabolites of zucchini fruit during cold storage and the mechanisms underlying the protective effects of ABA through an untargeted metabolomics approach. A time-dependent metabolic modulation could be observed in response to cold storage, where exogenously applied ABA elicited distinct metabolomic signatures. Supervised statistics were then used to identify methyl jasmonate, heliespirone C, and (indol-3-yl)acetyl-L-phenylalanine as the key compounds in the fruit exocarp having the highest discriminant ability. Noteworthy, the untargeted phenolic profile of zucchini exocarps was also distinctively modulated amid the different treatments. Overall, the implication of ABA in accumulating specialized metabolites, having a dual role in chilling injury mitigation during cold stress and increasing the nutraceutical properties of zucchini fruits, was observed. • Exogenous abscisic acid (ABA) was applied to zucchini fruits prior to cold storage. • Untargeted metabolomics approach showed the metabolic changes on zucchini exocarps. • Time-dependent modulation of specialized metabolites and polyphenols was reported. • Methyl jasmonate led the ABA-mediated response facing chilling injury mitigation. [ABSTRACT FROM AUTHOR]

Cold storage is widely used to preserve the physical and chemical qualities of fresh fruit and vegetables. However, some tropical and subtropical fruit are very sensitive to cold, exhibiting external and internal chilling injury (CI) symptoms when stored at low temperatures. In this study, we analyze the effect of UV-B irradiation on chilling injury and oxidative stress of zucchini fruit (Cucurbita pepo) from three hybrid cultivars that differ in their sensitivity to CI. Fruit with an average length of 20 cm was irradiated with 1.1 W m−2 of UV-B for 4 hours before storage for 7 days at 4 °C. The fruit of the three cultivars responded positively to UV-B, significantly reducing the CI index, weight and firmness loss, H 2 O 2 content, and membrane damage during cold storage. The fruit exposed to UV-B also exhibited higher levels of flavonoid content and antioxidant capacity, which correlated with a significant reduction in cold damage between cultivars and treatments. The expression of CpNCED1 , a key gene in the ABA biosynthesis pathway, increased in response to cold stress and UV-B treatment, suggesting that ABA could mediate the response to UV-B. Taken together, the results indicate that postharvest UV-B irradiation of zucchini fruit enhances chilling tolerance by triggering an increase in flavonoid accumulation and antioxidant capacity, and therefore reducing the oxidative stress generated during fruit storage at low temperature. • UV-B alleviated CI in zucchini cultivars contrasting for postharvest cold tolerance. • UV-B reduced H 2 O 2 and ion leakage, and increased fruit antioxidant capacity. • Both cold and UV-B upregulated the transcription of the ABA biosynthesis gene Cp NCED1. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate the effects of foliar sprays containing boron (B) nano-fertilizer (NF) on the growth and physiology of lettuce (Lactuca sativa) and zucchini (Cucurbita pepo). Plants were grown under greenhouse conditions for 60 days on a modified Hoagland solution with the presence and absence of boron (+B or –B). A synthesized B–NF foliar spray and a commercial B foliar fertilizer (Bortrac™ 150, BT) was applied at a concentration of 30 mg B L−1 at 10-d intervals throughout the experiment. The B–NF treatment increased the growth of lettuce 2.7- and 1.9-fold for shoots and roots, respectively, with an average production of lettuce biomass by ~58%. Similarly, the NF increased the growth of zucchini by 18 and 66% compared with Control–B (the absence of B), and 13 and 36% compared with BT, both for shoots and roots, respectively. Nevertheless, NF + B mostly decreased lettuce growth with symptoms of B toxicity in leaves. In lettuce, addition of B did not affect concentrations of phenols; however, in zucchini, Control–B induced a higher production of phenolic compounds possibly related to B deficiency. The B addition in lettuce reduced the DPPH activity by 32 and 21% in NF and BT, respectively, compared to Control-B. These responses were similar in zucchini; however, the effect of B was product of its presence in mineral solution rather than due the foliar product applied. This suggests that a NF-based delivery system for B may be highly effective at boosting plant productivity on B-limited soils. • A Boron (B)-based nanoparticle fertilizer (NF) was synthesized. • The synthesized B-based NF increased lettuce and zucchini root and shoot biomass. • The absence of B induced greater production of phenolic compounds. • The synthesized B-based NF was effective at overcoming B limitation. [ABSTRACT FROM AUTHOR]

Pollen and nectar can be contaminated with a range of pesticides, including insecticides, fungicides, and herbicides. Since these matrices are important food sources for pollinators and other beneficial insects, their contamination can represent a key route of exposure. However, limited knowledge exists with respect to pesticide residue levels and their dynamics in these matrices for many crops and active ingredients (AIs). We used controlled glasshouse studies to investigate the residue dynamics of a systemic (cyprodinil) and a contact (fludioxonil) fungicide in the floral matrices and other plant parts of courgette/zucchini (Cucurbita pepo L.). We aimed to better understand the processes behind residue accumulation and decline in pollen and nectar. Each AI was applied to plants, either by spraying whole plants or by targeted spraying onto leaves only. Samples of pollen, nectar, anthers, flowers, and leaves were taken on the day of application and each subsequent morning for up to 13 days and analysed for residues using LC-MS/MS. Significant differences in residue levels and dynamics were found between AIs and floral matrices. The present study allowed for the identification of potential routes by which residues translocate between tissues and to link those to the physicochemical properties of each AI, which may facilitate the prediction of residue levels in pollen and nectar. Residues of the contact AI declined more quickly than those of the systemic AI in pollen and nectar. Our results further suggest that the risk of oral exposure for pollinators may be considerably reduced by using contact AIs during the green bud stage of plants, but application of systemic compounds could still result in a low, but continuous long-term exposure for pollinators with limited decline. [Display omitted] • Pesticide residue dynamics in pollen and nectar varied between contact and systemic pesticides. • Limited decline of the systemic pesticide in pollen was observed when sprayed prior to flowering. • Relationships between residues in different floral matrices varied depending on the pesticide used. • The temporal variations of residues in pollen and nectar were investigated. [ABSTRACT FROM AUTHOR]

• Low temperature induces CpMYB106-like in the cold-tolerant 'Natura' fruit. • 'Natura' promoter, proMYB106A, shows higher basal expression. • Acclimation after cold stress increases GUS expression driven by proMYB106A. • Salt and MeJA upregulate both promoters, but most prominently proMYB106A. • CREs occurrence and distribution in 'Natura' promoter could lead to higher expression. Zucchini fruit (Cucurbita pepo L.) is susceptible to chilling injury (CI) during its postharvest life, with this response being cultivar-dependent. A previous transcriptomic analysis comparing cold-tolerant fruit from the cultivar 'Natura' with cold-sensitive fruit from the cultivar 'Sinatra', revealed the transcription factor (TF) CpMYB106-like as a relevant candidate gene for the acquisition of postharvest low-temperature tolerance. C. pepo has two CpMYB106-like paralogs, which are differentially present in the 'Natura' (CpMYB106-likeA) and 'Sinatra' (CpMYB106-likeB) cultivars due to gene and promoter deletions. The aim of this study was to investigate the transcriptional regulation of the CpMYB106-like paralogs to unravel their role in the postharvest life of zucchini fruit. For this, gene expression was analyzed and promoter sequences and their activities were studied through reporter β-glucuronidase (GUS) gene analysis in heterologous systems. An expression analysis showed that CpMYB106-like mRNA levels were induced only in the cold-stored fruit of 'Natura'. The analysis of the promoter sequences showed numerous cis -regulatory elements (CREs), many of which have a differential distribution or frequency between the two paralogs. Promoter basal activity was determined by transient transformation of Nicotiana benthamiana leaves, which showed a higher expression driven by the promoter from the cold-tolerant cultivar 'Natura', which could be explained by the presence of three additional copies of the enhancer element EECCRCAH1 in proMYB106A. The tissue-specific expression pattern, and the response to abiotic stresses and phytohormones controlled by CpMYB106-like promoters was analyzed in transgenic Arabidopsis thaliana plants. GUS activity was mainly detected in the vascular system, leaves, and inflorescences, especially in siliques. With respect to abiotic stresses, low temperature decreased GUS expression in Arabidopsis, but increased it in plants carrying the 'Natura' promoter after a 24-h acclimation period at 22 °C. Salt treatment induced GUS activity driven by both promoters in Arabidopsis seedlings, but it was higher with the 'Natura' promoter. Furthermore, methyl jasmonate (MeJA) also induced a sharp increase of GUS controlled by proMYB106A. These results suggest that the regulation of CpMYB106-like TFs in zucchini is promoter-driven, and reveal the involvement of these genes in the acquisition of cold tolerance in fruit during postharvest stress conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

Among the numerous benefits of porous carbon materials, their economic viability, abundance of availability, and environmental sustainability have made them increasingly popular in the realm of energy transformation and storage. Herein, the rotted Cucurbita pepo L. precursor was served as the starting material for the production of nitrogen (N) and oxygen (O) co-doped porous activated carbon, which was involved in high-temperature carbonization and KOH activation processes. The rotted Cucurbita pepo -derived activated carbon (RCPAC) showcases a remarkably elevated specific surface area of 2434 m2 g−1, while its micropore volume is 0.73 cm3 g−1. These inherent attributes offer a significant quantity of electroactive sites that effectively enable the electrochemical process of adsorption as well as the desorption of electrolyte ions. The RCPAC electrode demonstrates a notable specific capacitance value of 208 F g−1 when subjected to the current density of 1 A g−1. Furthermore, it retains >99 % of its original capacitance even after undergoing 10,000 cycles at a current density of 10 A g−1. Moreover, a symmetric supercapacitor (SSC) consisting of RCPAC electrodes and 6 M potassium hydroxide (KOH) electrolyte results in a significant specific capacitance of 55 F g−1 at 0.25 A g−1. The SSC demonstrates an impressive retention of capacitance, amounting to 85.6 %, even subsequent to enduring a substantial number of 8000 charge/discharge cycles. Additionally, an SSC was assembled using two undifferentiated RCPAC-6 electrodes in [BMIM]BF 4 /AN electrolyte. The SSC exhibits an impressive energy density of 92.25 Wh kg−1, while simultaneously maintaining a power density of 374.9 Wh kg−1. Furthermore, it demonstrates a capacitance retention surpassing 72.6 % subsequent to enduring 5000 cycles at 2 A g−1. Our research elucidates a financially feasible methodology for the fabrication of porous carbon-based compounds, which exhibit immense potential for deployment in various energy conversion and storage. [Display omitted] • The low-cost and eco-friendly RCPAC is prepared using rotted Cucurbita pepo. • The morphology and structure of RCPAC are adjusted by the ratio of RCP to KOH. • RCPAC-6 consists of a honeycomb porous carbon structure. • RCPAC-6 achieves excellent specific capacitance and rate performance. • A symmetric supercapacitor exhibits an energy density of 92.25 Wh kg−1 at 374.9 W kg−1. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the possibility of using pumpkin (Cucurbita pepo) seed husks as a low-cost sorbent to remove dyes popular in the textile industry, that is, anionic dyes: Reactive Black 5 (RB5) and Reactive Yellow 84 (RY84), and cationic dyes: Basic Violet 10 (BV10) and Basic Red 46 (BR46). The sorbent was subjected to the Fourier-transform infrared spectroscopy (FTIR) analysis. The scope of the research included also the determination of pH (pH 2-11) influence on the efficiency of dye sorption, sorption kinetics (equilibrium time, pseudo-first-order model, pseudo-second-order model, intramolecular diffusion model), and sorption capacity (Langmuir 1 and 2 models, Freundlich model). The optimum pH range for RB5 and RY84 sorption on the tested sorbent was pH 2-3. In the case of BV10, sorption was most effective at pH 3 and in the case of BR46 at pH 6. In each case, the best fit to the experimental data was shown for the pseudo-second order model. The intramolecular diffusion model showed the sorption of each dye to proceed in the three main stages, varying in intensity and duration. Pumpkin seed husk sorption capacity of the anionic dyes was 0.96 mg g-1 for RB5 and 1.08 mg g-1 for RY84. In the case of cationic dyes, the sorption capacities of the tested sorbent were many time higher and reached 96.01 mg g-1 for BV10 and 163.39 mg g-1 for BR46. [ABSTRACT FROM AUTHOR]

In this study, size and shape controlled biogenic synthesis of gold nanoparticles and their antibacterial activity against food borne bacterial pathogens were investigated. Synthesis of gold nanoparticles was carried out using two medicinally important plants Cucurbita pepo and Malva crispa and the size and shape of the nanoparticles were controlled by altering various parameters in the reaction medium. Results obtained from UV–Vis, FE-SEM, EDS and HR-TEM analyses supported the nanoparticles formation. FT-IR analysis confirmed the presence of biomolecules in the plant leaves extracts responsible for reducing and capping agents. Interestingly, the plant extract synthesized gold nanoparticles showed effective inhibition zone against Gram-positive and Gram-negative pathogens. The minimum inhibitory concentration (MIC) of synthesized gold nanoparticles at 400 μg/ml concentration showed effective inhibitory activity against Escherichia coli and Listeria monocytogenes. Conductivity of the medium continuously increased during the nanoparticles treatment with food borne bacterial pathogens resulting in indirect indication of the disruption of bacterial cell membranes. In addition, mode of interactions of gold nanoparticles against food borne bacterial pathogens was demonstrated using Bio-TEM analysis which is clear evident for the disruption of bacterial cell membranes. [ABSTRACT FROM AUTHOR]

It is known that epibrassinolide (EBL) plays an important role in the variety of plant developmental processes and adaptation to various environmental stresses. Salt stress is one of the most important environmental problems which limit crop growth and productivity. Here, the effects of EBL pretreatment on amelioration of the adverse effects of salinity were investigated in pumpkin, especially at the establishment stage. For this purpose, uniform-sized seedlings were transplanted to plastic containers containing one-half-strength Hoagland's nutrient solution. EBL was added at 0.1 and 0.01 μM to the hydroponic medium for 5 days before stress. The plants were treated with 40 and 80 mM NaCl for inducing salinity stress. Salt stress reduced the plant growth, calcium and potassium content in leaves and roots, and these detrimental effects were alleviated when plants were pretreated with EBL. Salinity stress caused a significant increase in lipid peroxidation, sodium, and γ-amino butyric acid (GABA) content. EBL pretreatment ameliorated these effects by reducing lipid peroxidation, sodium content and increasing GABA content. The increase in activities of guaiacol peroxidase, catalase, ascorbate peroxidase, and superoxide dismutase was observed under salinity stress. Application of exogenous EBL pretreatment further increased antioxidant enzymes activities. The present work emphasizes the protective role of EBL in the regulation of antioxidant enzymes and GABA accumulation and its possible link in amelioration of stress in plants. This is the first report dealing with EBL effect on GABA content under salt stress. • In pumpkin seedlings, EBL pretreatment promotes growth, calcium and potassium content of leaves and roots under salinity. • EBL pretreatment reduces lipid peroxidation caused by salinity. • EBL pretreatment further increases GABA content and antioxidant enzymes activities in leaves and roots under salinity. [ABSTRACT FROM AUTHOR]

• Seed yield and fruit characteristics of pumpkin grown under field conditions were investigated. • The yield and quality components could be explained strongly by the Principal Component Analysis in irrigated as well as in drought conditions. • The inbred pumpkin line G9 was observed to be the most superior genotype in terms of yield and fruit number in both irrigation and drought conditions. Climate change-associated drought stress in plants is one of the major environmental factors that cause a reduction in plant growth, development, and productivity. Therefore, an improvement to obtain superior genotypes that are highly adaptable to arid and semi-arid conditions remains the main objective of the future breeding efforts. In this context, the present study was conducted to determine the genotypic differences among 16 inbred lines and 4 commercial cultivars of pumpkin associated with the parameters such as certain fruit characteristics, seed yield, and seed quality in irrigated and drought conditions. In the growing season of pumpkin, the amount of irrigation water applied was 402.6 mm in 2017 and 425.4 mm in 2018. In all the evaluated parameters, the examined genotypes exhibited a wide range of significant differences between the irrigated and drought conditions in both the years. Moreover, a significant positive correlation was observed between seed yield and fruit number, seed-thickness and plant height, and 1000-seed weight and seed size. In terms of seed quality, 1000-seed weight was determined to be a prominent parameter. The results of the present study demonstrated that these relationships imply a significant potential for the selection of genotypes with superior performance in both conditions. Furthermore, principal component analysis (PCA), performed considering the Eigenvalues, indicated that the yield and quality components could be explained strongly by the PCA analysis in irrigated as well as in drought conditions. Finally, the inbred line G9 was observed to be the most superior genotype in terms of yield and fruit number in both irrigation and drought conditions; therefore, this inbred line is envisaged to be evaluated in future breeding studies and to be included in future hybrid programs in order to develop drought-tolerant cultivars. [ABSTRACT FROM AUTHOR]

• Cucurbita pepo showed accumulation of polychlorinated biphenyls. • Two major latex-like proteins were detected in xylem sap from C. pepo. • Major latex-like proteins in xylem sap of C. pepo bound polychlorinated biphenyls. • Critical steps for the accumulation of hydrophobic pollutants were revealed. Hydrophobic pollutants, such as polychlorinated biphenyls (PCBs), are detected at high concentrations in plants of the Cucurbitaceae family, including cucumber and zucchini. Given that the uptake of these compounds by crops can lead to their accumulation in animals via the food chain and that they may have potentially adverse health effects, it is desirable to take appropriate preventative measures. However, the mechanisms underlying the uptake of these pollutants are still unclear. We found that the Magda (MG) cultivar of Cucurbita pepo showed high accumulation of PCBs, especially 2-chlorinated PCBs, in leaves, stems, and xylem sap compared with the Patty Green (PG) cultivar. In the MG cultivar, we identified two major latex-like proteins (MLPs) produced in roots that are translocated to xylem sap, wherein they bind to PCBs, and it is assumed that these MLPs are associated with the accumulation of PCBs in the aerial parts of plants. These results indicate that PCBs are transported by specific mechanisms via the xylem sap. Collectively, our findings indicate that the expression of MLP genes and production of MLPs in roots, the excretion of MLPs into xylem sap, and the binding of hydrophobic pollutants by MLPs are critical steps in the accumulation of hydrophobic pollutants in cucurbits. [ABSTRACT FROM AUTHOR]

Quantitative and precise measurement of plant growth is the foundation for the understanding of mechanisms that regulate the growth of plant. Plant growth is a highly dynamic process that could start/stop within seconds, but existing methods provide little information on the dynamic growth due to insufficient resolution. Here, we report on a simple manufacturing process and materials for wearable strain sensor, and a highly sensitive, automatic and real-time approach to assess the growth of plant in the range from nanometer level to centimeter level. By taking the synergistic reinforcement between graphite and carbon nanotube (CNT) membranes, a flexible, stretchable and wearable carbon nanotube/graphite sensor was obtained by simply depositing a graphite ink, a CNT ink and solidifying under ambient environment. An all-in-one device composed of the sensor and a home-made readout circuit was used to make the real-time measurement of plant growth. The monitoring of Solanum melongena L. and Cucurbita pepo captured the evidence of a rhythmic growth pattern for the fruits: the fruits grow rapidly for seconds and then rest for seconds. This approach simplified the procedure, reduced the cost, enhanced the speed, and provided nanoscale sensitivity for plant, presenting promising potentials in plant growth measurement. Image 1 [ABSTRACT FROM AUTHOR]

The present work showed the green, eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) using leaf extract of Cucurbita pepo. The prepared ZnO NPs were studied using different characterization techniques such as Fourier transform infrared (FTIR), X-ray diffraction (XRD), UV–Visible spectroscopy (UV–Vis) and Transmission electron microscopy (TEM). TEM images confirmed the formation of NPs with average size of 8 nm. XRD showed the crystalline nature of prepared ZnO NPs. This shows that the ZnO NPs induced cytotoxicity that affected the proliferation of MG63 osteoblast-like cells in a concentration dependent manner. Further, the ZnO NPs induced reduction in cell proliferation was confirmed by Fluorescein diacetate hydrolysis (FDA) staining. FDA staining results showed a reduction in fluorescence intensity with an increase in the concentration of ZnO NPs. The untreated control which was unaffected showed the highest fluorescence compared to ZnO NPs treated samples. A significantly diminished fluorescence was observed in samples incubated with 80 ppm ZnO NPs. In conclusion, these cell experimental results confirmed that the fabricated ZnO NPs are an important substitute for osteoporotic and bone tissue formation. Unlabelled Image • Biofabrication Zinc oxide nanoparticles (ZnO NPs) using Cucurbita pepo leaf extract. • proliferation of MG63 osteoblast-like cells by ZnO NPs. • Dose dependant effect of ZnO NPs on osteoblasts. • Important substitute for osteoporotic and bone tissue formation. [ABSTRACT FROM AUTHOR]

This study investigates the effect of SPIONs (superparamagnetic iron oxide nanoparticles, ∼12.5 nm in size) on summer squash plant (Cucurbita pepo) in the presence and absence of supplementary iron (Fe(II)-EDTA). The plants were grown in nutrient solution with different iron sources: (i) Fe(II)-EDTA, (ii) without Fe(II)-EDTA (iii) SPIONs only, and (iv) Fe(II)-EDTA with SPIONs. Plant growth and development were assessed after 20 days of soaking by measuring phenological parameters such as plant biomass, chlorophyll content, amount of carotenoids, and the catalase enzyme activity. Transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, X-ray diffraction, and vibrating sample magnetometer methods were used to detect uptake and translocation of SPIONs in plant tissues. Our results showed that SPIONs treatment (without Fe(II)-EDTA) caused growth retardation and decreased the plant biomass and chlorophyll content. Hence, they are not efficient sources to compensate for iron demand of squash plant. Electron microscopy observations, magnetization and elemental analyses revealed that SPIONs are taken-up by plant roots but not translocate to upper organs. In roots, SPIONs use a symplastic route for intercellular transfer. These findings suggest that as an iron source, SPIONs alone are not efficient for plant growth, but can contribute it together with Fe(II)-EDTA. • Superparamagnetic iron oxide nanoparticles (SPIONs, Fe 3 O 4 , ∼12.5 nm) and ionic iron (Fe(II)-EDTA) are subjected to squash. • SPIONs alone (without Fe(II)-EDTA) caused growth retardation and decreased plant biomass. • SPIONs are taken-up by plant roots but not translocate to aerial organs. • SPIONs alone are not efficient for plant growth, but can contribute it together with Fe(II)-EDTA. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Plastic pollution in agricultural soil is a growing environmental concern. • We tested different types of biodegradable plastic mulches (BDMs) in field experiments. • BDMs compared favorably against polyethylene mulch. • Effects of different BDMs on soil health were not consistent over time and site. • BDMs are a promising alternative to polyethylene, but longer-term testing is needed. Abstract Plastic pollution in agricultural soils, caused by the incomplete removal of polyethylene mulch after usage, is a growing environmental concern. There has therefore been increased interest in biodegradable plastic mulches as alternative to polyethylene mulch; however, little is known about their impact on soil health. We evaluated the effects of four biodegradable plastic mulches on soil health at two sites (Knoxville, TN and Mount Vernon, WA) under pie pumpkin (Cucurbita pepo) production. Cellulosic paper, polyethylene, and no-mulch served as controls. Soil health was first assessed in May 2015, and then every six months until May 2017, by measuring 19 soil properties (physical, chemical, and biological). Soil properties were converted to index scores and aggregated into six soil health indicators and five soil functions. The results showed poor correlations and high spatial variations for most of the soil properties. We performed repeated measure analyses using raw values and change scores to account for the initial variations. The soil properties, soil health indicators, and soil functions were affected more by site and time than by the mulch treatments. Nonetheless, we did observe significant effects of some of the mulch treatments on six soil properties (aggregate stability, infiltration, soil pH, electrical conductivity, nitrate-N, and exchangeable potassium), four soil health indicators (hydraulic, biological, fertility, and salinity & sodicity), and one soil function (nutrient cycling). However, these effects were not consistent among all the biodegradable plastic mulches, across the two sites, and the sampling times. Overall, biodegradable plastic mulches may be a viable alternative to polyethylene. However, evaluation under long-term studies is needed to better establish their effects on soil health. [ABSTRACT FROM AUTHOR]

In most cases, final agricultural products such as vegetables, fruits, and cereals are associated with the industrial generation of byproducts that are usually unexploited to express all their potential value or, in the worst but common case, directly disposed of as wastes. Even after industrial processing, plant biomasses still represent an invaluable source of unique and human-useful compounds. Within the circular economy, the valorization of industrial wasted biomasses is considered an opportunity to provide new higher-value products with a concomitant solution to waste accumulation issues. In this framework, pointing to circularity, the seed hulls industrial residuals discarded as waste deriving from Cucurbita pepo L. (pumpkin) are hereby investigated to be re-entered in a circular valorization chain. After a full characterization of the biomass residual, the focus was set on cucurbitin, a biologically active non-proteic amino acid found only in the Cucurbita species. The present research investigates different water-based strategies for cucurbitin extraction and enrichment. LCA comparative analysis has been performed to evaluate the environmental impacts of the extractions and assess the most sustainable strategy to yield cucurbitin. [Display omitted] • Pumpkin seed hulls are confirmed as added-value biomass source. • The amino acid cucurbitin is extractable in water and ethanol/water solvents. • It is possible to enrich extracts in cucurbitin up to 30%. • LCA highlights non-negligible differences in relation to energy consumption. [ABSTRACT FROM AUTHOR]

• Hydropriming had no advantage over the control in terms of increasing dry matter and gas exchange. • Priming methods that increased K +/Na+ and respiration were effective in reducing the effect of sodicity and salinity stress. • Nanopriming with titanium oxide was the only treatment that improved dry matter in sodic soil irrigated with saline-sodic water. • Chemopriming was one of the best treatments in all water and soil conditions, except for sodic soil irrigated with saline-sodic water. • In saline soil irrigated with non-saline non-sodic water, osmopriming with zinc sulfate was as beneficial as chemopriming and nanopriming. Salt stress is one of the most important environmental stresses affecting the growth, quantity, and quality of agronomic crops. This study was undertaken to investigate the effect of seed priming on the salt tolerance of pumpkin seedlings. Seeds were primed with eight different treatments including control (pre-soaking), Hydropriming with deionized water, Nanopriming with TiO 2 , Chemopriming with putrescine, Biopriming with Pantoea agglomerans and Pseudomonas putida bacterias, Hormone priming with salicylic acid, plant extract priming with Moringa (Moringa oleifera), and osmopriming with zinc sulfate. After germination, two groups of sampling were grown in two types of soil: saline (Ssa) and sodic (Sso) and they were investigated separately and irrigated with two types of water: saline-sodic (Wss) and non-saline-non-sodic (Wnss). Results showed that under Wnss/Ssa conditions, hydropriming did not affect the TAC and K +/Na+, as well as TDM and gas exchange parameters, while osmopriming increased all parameters. Likewise, in this soil-water condition, the osmopriming increased respiration and dry matter by 21.8%, while it increased photosynthesis in all four soil-water conditions. Hormone priming in Wss/Ssa conditions caused a 31% increase in dry matter, while it did not affect SOD, Proline, and TAC, moreover, respiration and K +/Na+ also increased. In Wss/Sso, nanopriming was the only superior treatment in terms of dry matter with a 10% increase compared to the control. In mentioned soil water condition, nanopriming was among the treatments with the highest values of SOD, TAC, Proline, and K +/Na+, respiration, and the lowest values of MDA and Na+. In all conditions except Wss/Sso, biopriming increased dry matter. In the mentioned condition, despite having higher SOD, and proline compared to the control, biopriming did not lead to an increase in respiration and K +/Na+. In Wss/Ssa conditions, biopriming led to the highest increase in the dry matter by 34.1%, while it had no effect on proline and TAC and increased K +/Na+ by 3.7 times compared to the control. Priming with plant extract also increased dry matter in all conditions except Wss/Sso. In the condition of Wss/Ssa, even though the priming of the plant extract did not affect TAC and proline, it caused an increase in K +/Na+ compared to the control, in addition, it was one of the superior treatments in terms of respiration. In conclusion, seed priming through ionic regulation was found to be effective in reducing the harmful effects of salinity and sodicity stress in pumpkin seedlings. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) plays an important role in the regulation of several stress responses such as drought, high salinity and low temperature being also proved as a key phytohormone for the acquisition of postharvest cold tolerance in zucchini fruit. Therefore, it would be of great interest to unravel the mechanisms implicated in the ABA response, using a metabolomic approach. The aim of this work has been to use a combination of metabolomic tools to identify the main metabolic pathways involved in ABA-mediated regulation of chilling tolerance in zucchini fruit. As a result of this study, it was found that ABA modulates the primary metabolism inducing the accumulation of some sugars, organic acids such as succinic acid and amino acids including histidine, serine, phenylalanine, glutamic acid and γ-aminobutyric acid, and that are involved in low-temperature tolerance. ABA treatment also activates the t-zeatin and riboflavin biosynthesis during the first days of cold storage which can be important signals in the ABA-mediated cold response to induce tolerance in zucchini fruit. [Display omitted] • Abscisic acid (ABA) improves postharvest quality of zucchini fruit. • Targeted metabolomics reveals an ABA modulation of the primary metabolism. • An accumulation of sugars, organic acids and amino acids induced chilling tolerance. • Secondary metabolism was also affected by ABA treatment. • ABA activates the t-zeatin and riboflavin biosynthesis at first day of cold stress. [ABSTRACT FROM AUTHOR]

Oil pumpkin is a major emerging alternative crop with several unresolved weed management questions in central-eastern Europe, one of the focal regions of oil pumpkin production worldwide. This study aims to assess the importance of three groups of factors: environment, non-chemical management (all management excluding herbicides), and chemical weed management, in determining the weed species composition of oil pumpkin crops in Hungary. We surveyed the weed flora of 180 oil pumpkin fields across the country, along with 32 background variables. Applying a minimal adequate model consisting of 18 terms with significant net effects, 30.8% of the total variation in weed species data could be explained. Most variation in species composition was determined by environmental factors, with climatic conditions (precipitation and temperature) being most influential. The net effects of seven non-chemical management variables (preceding crop, N and P fertilisers, seeding rate, crop cover, cultivating tillage, and manual weed control), and two herbicides (S-metolachlor and linuron) were also significant. Variation partitioning demonstrated the dominance of environmental factors, and it also showed that non-chemical management practices accounted for five times more variance than herbicides. Within non-chemical management, the relative impact of cultural variables was nearly five times larger than that of mechanical weed management. Among the abundant weeds, Chenopodium polyspermum and Ambrosia artemisiifolia were positively associated with precipitation, Datura stramonium and Hibiscus trionum correlated with higher temperature, and Chenopodium album favoured larger potassium content of the soil. High seeding rate and crop cover suppressed Amaranthus retroflexus , cultivating tillage reduced Ambrosia artemisiifolia and Setaria pumila , while conspicuous tall weeds like Abutilon theophrasti and Chenopodium album were most vulnerable to manual weed control. Although the short stature of pumpkin with its poor weed-suppressive ability could unfavourably influence the results of some cultural practices, our findings suggest that the weed vegetation of oil pumpkin fields can be efficiently managed also with environmentally benign methods. [ABSTRACT FROM AUTHOR]

Soilless zucchini ( Cucurbita pepo L.) crops were grown in two distinct cropping periods (spring-summer; SS and autumn-winter; AW) using irrigation water with different Ca 2+ concentrations (1.5, 3, 4.5 and 6 mM). The objectives of this study were to: (i) mathematically correlate the accumulation of Ca 2+ in the root environment with the respective Ca 2+ /water uptake ratio (namely uptake concentration; UC), and (ii) determine the UC of macronutrients (i.e., N, P, K, Ca and Mg) under these conditions. Equations of the literature, initially developed to predict NaCl accumulation in a closed hydroponic system, were further extended to fit experimental results. The evolution of Ca 2+ accumulation in the drainage exhibited a sigmoid pattern with time and the relationship between the concentration of Ca 2+ in the root zone and the corresponding uptake ratio Ca 2+ /water was better described by curvilinear functions. Validation of the model showed a very good agreement between simulated and measured values. Increasing Ca 2+ levels affected both tissue concentrations and UC of Ca and N, but this was not the case for P, K, and Mg. Photosynthesis, growth, yield and plant water uptake were restricted (avg. 15% decrease) at high external Ca 2+ levels, due to high total salt concentration (EC) in the recycled solution (4.2–5.5 dS m −1 ). Fruit quality attributes, however, remained unaffected by treatments with the exception of fruit nitrate content. The empirical model parameterized and tested in this work may serve as a tool to predict Ca 2+ ion concentrations in the root environment of zucchini crops as relationships of the water absorbed by the crop. Finally, the results showed that in soilless zucchini crops with zero discharge of fertigation effluents, there is no compelling reason not to use irrigation water resources with Ca 2+ concentration up to 3 mM. [ABSTRACT FROM AUTHOR]

Pumpkin seed ( Cucurbita pepo L.) is high in oil, protein and total unsaturated fatty acids (TUFA), and provides an important source of nutrition and income globally. Use of pumpkin seed in the snacking and vegetable oil industry in the U.S. is expected to rise as the market for healthy foods increases. Currently, most of the pumpkin seed consumed in the U.S. is imported, and there is need to breed high-yielding and nutritious cultivars that are locally adapted to various agro-ecological growing zones in the country. In the current study, phenotypic variation of key seed nutrition traits among 35 C . pepo accessions of different seed phenotypes (hulled, semi-hulled, thin layer and ‘naked’) was determined with the primary goal of identifying the best parental material for breeding as well as elucidating phenotypic relationships among the traits. Seed oil percentage ranged from 29.33% to 48.41% and was significantly (P < 0.05) negatively correlated (−0.51) with seed protein percentage, which ranged from 19.48% to 31.35%. Linoleic acid (x̅ = 51.19%) was the major fatty acid in the seed, followed by oleic (x̅ = 30.77%), palmitic (x̅ = 9.84%), and stearic (x̅ = 5.63%) acid. Significant negative correlations were found between linoleic and oleic acid (−0.96), linoleic and stearic acid (−0.37), and seed size and seed protein percentage (−0.39). Conversely, significant positive correlations were found between seed size and oil content (0.56–0.70), seed size and palmitic acid (0.49–0.65), seed size and stearic acid (0.38–0.46), palmitic acid and seed oil percentage (0.50), and stearic acid and seed oil percentage (0.31). Hulled seed accessions were significantly lower in seed oil percentage, palmitic acid and seed size than ‘naked’ seed accessions. On the other hand, ‘naked’ seed accessions had significantly lower seed protein percentage than semi-hulled seed accessions. Collectively, this data suggests a wide variation in seed nutrition within C. pepo and provides insight into the phenotypic relationships among important seed traits. Several accessions high in oil, protein and TUFA were identified and will be useful in breeding for enhanced pumpkin seed nutrition. [ABSTRACT FROM AUTHOR]

DNA typing has been long proposed as a component of food traceability especially for the ability to provide genetic information on processed and/or mixed commercial products. However, the use of DNA testing to deliver legal evidence has been very limited in the agro-food chain, also because in this field, a genetic concordance is rarely sustained with indications on the interpretation and statistics of a DNA profile. Zucchini is the most important and diverse horticultural group belonging to Cucurbita pepo , a plant species that yields a large variety of edible fruits such as squashes and pumpkins. Challenges in genetic discrimination of zucchini material exiting the agro-food chain typify the problems in DNA typing of horticultural food products, because of limited allelic diversity, presence of common alleles, highly processed food and genetic similarity with other edible species. The aims of this work were to identify zucchini varieties in commercial products by a means of Simple Sequence Repeat (SSR) analysis and to provide indications for the statistical interpretation of a match. We assessed the efficacy of SSRs analyzing some of the most diffused hybrids and open pollinated zucchini varieties. SSRs were also screened for transferability in DNA isolated from edible organs of different plant species that are frequently present in food products containing zucchini. Moreover, we demonstrate the possibility to identify the variety in food products of different origins. The statistical evaluation on the rarity of DNA profiles in zucchini indicated that the genetic match presented in this work cannot be attributed to chance alone. Based on this evidence, the advantages and pitfalls of food DNA typing for variety identification of a horticultural crop are discussed. [ABSTRACT FROM AUTHOR]

• Accurate plant classification is required in order to use genetic resources for the right purpose. • Molecular markers are effective for plant classification. • The development of SNP markers is key to managing plant genetic resources at the genebank. • Effective SNP markers were developed for Cucurbita species discrimination. There are five domesticated species in the genus Cucurbita. These are Cucurbita. pepo, Cucurbita maxima, Cucurbita moschata, Cucurbita ficifolia , and Cucurbita argyrosperma. Cucurbita has a large genetic diversity, with various growth forms, sizes, shapes, colors, compositions, tastes, and resistance to biotic and abiotic factors. Maintaining the biological diversity of genetic resources and managing the right historical information are important first steps in the development of new varieties with desirable traits. This study presents the classification of Cucurbita species using DNA barcodes and the development of powerful single nucleotide polymorphism (SNP) markers that can distinguish the five Cucurbita species. A total of 54 accessions from five Cucurbita species (C. pepo, C. maxima, C. moschata, C. ficifolia, and C. argyrosperma) were used for SNP marker development. The chloroplast DNA was extracted, and the three universal barcoding regions (matK, trnH-psbA , and rbcL) were sequenced. Neighbor-joining (NJ) trees were constructed using the nucleotide sequence of the cpDNA barcodes. The rbcL and trnH-psbA barcodes failed to differentiate between C. moschata and C. argyrosperma , whereas the matK region efficiently differentiated with 87% bootstrap support. Moreover, the matK region showed a species identification rate of 100%, making it an efficient marker for identifying the five domesticated Cucurbita species. Multiplex SNaPShot (mini sequencing) analysis of four SNPs in the matK region revealed four species-specific SNPs that effectively classify Cucurbita species into five groups. When all four markers are used together, they are effective. These four species specific SNP markers were validated using known Cucurbita germplasm (111 accessions) and applied for the species identification of unknown Cucurbita germplasm (370 accessions) available at the RDA gene bank in the Republic of Korea. These markers were 100% effective for identifying the five Cucurbita species. Therefore, these SNP markers can be used for effective management of Cucurbita genetic resources in genebanks around the world. [ABSTRACT FROM AUTHOR]

Xylem sap is a fluid that transfers water and nutrients from the rhizosphere. This sap contains relatively low concentrations of proteins that originate from the extracellular space among the root cells. One of the characteristic proteins in the xylem sap of the Cucurbitaceae family, which includes cucumber and zucchini, is a major latex-like protein (MLP). MLPs are responsible for crop contamination through the transport of hydrophobic pollutants from the roots. However, detailed information on the content of MLPs in the xylem sap is not available. Proteomic analysis of root and xylem sap proteins from the Cucurbita pepo cultivars Patty Green (PG) and Raven (RA) showed that the xylem sap of cv. RA, a high accumulator of hydrophobic pollutants, contained four MLPs that accounted for over 85% of the total xylem sap proteins in this cultivar. The xylem sap of PG, a low accumulator, mainly contained an uncharacterized protein. The amount of each root protein between the PG and RA cultivars was significantly and positively correlated in spite of being with and without a signal peptide (SP). However, the amount of xylem sap proteins without an SP was not correlated. These results suggest that cv. RA is characterized by MLPs in the xylem sap. • Proteomic analysis revealed characteristic proteins in the Cucurbita pepo. • Major latex-like proteins were detected in a high accumulator of pollutants. • An uncharacterized protein was contained in a low accumulator of pollutants. • There were many leaderless secreted proteins in the xylem sap of C. pepo. • Xylem sap proteins characterized a high accumulation of pollutants in C. pepo. [ABSTRACT FROM AUTHOR]

Cucurbitaceae species are used in traditional medicine around the world. Cucurbitacins are highly oxygenated triterpenoids found in Cucurbitaceae species and exhibit potent anticancer activity alone and in combination with other existing chemotherapeutic drugs. Therefore, increasing production of these specialized metabolites is of great relevance. We recently showed that hairy roots of Cucurbita pepo can be used as a platform for metabolic engineering of cucurbitacins to modify their structure and increase their production. To study the changes in cucurbitacin accumulation upon formation of hairy roots, an empty vector (EV) control and Cucurbitacin inducing bHLH transcription factor 1 (CpCUCbH1)-overexpressing hairy roots of C. pepo were compared to untransformed (WT) roots. Whilst CpCUCbH1 -overexpression increased production of cucurbitacins I and B by 5-fold, and cucurbitacin E by 3-fold when compared to EV lines, this increase was not significantly different when compared to WT roots. This indicated that Rhizobium rhizogenes transformation lowered the cucurbitacins levels in hairy roots, but that increasing expression of cucurbitacin biosynthetic genes by CpCUCbH1 -overexpression restored cucurbitacin production to WT levels. Subsequent metabolomic and RNA-seq analysis indicated that the metabolic profile and transcriptome of hairy roots was significantly changed when compared to WT roots. Interestingly, it was observed that 11% of the differentially expressed genes were transcription factors. It was noteworthy that the majority of transcripts showing highest Pearson correlation coefficients to the Rhizobium rhizogenes genes rolB , rolC and ORF13a , were predicted to be transcription factors. In summary, hairy roots are an excellent platform for metabolic engineering of plant specialized metabolites, but these extensive transcriptome and metabolic profile changes should be considered in subsequent studies. • Rhizobium -mediated transformation significantly changes the metabolic profile and transcriptome of infected plant tissues. • 11% of the 9905 differentially expressed genes between hairy roots and wild type roots were transcription factors. • Squash genes which expression profile correlate with rol genes/ORFs , encode transcription factors. [ABSTRACT FROM AUTHOR]

Natural plant growth biostimulants are intensively used nowadays for plant growing in normal and adverse conditions. Severely affected by salt and drought stresses, squash ( Cucurbita pepo L.) is an important vegetable crop that highly ranked in economic importance worldwide. The current study aimed to evaluate whether leaf extract of Moringa oleifera ( MLE), as a novel natural biostimulant for plant growth, could play a role in improving drought tolerance in squash plants under saline condition. In summer and fall seasons of 2016, MLE (3%) was foliar sprayed for plants under full (100% of ETc) or deficit irrigation (DI; 80 or 60% of ETc). The effect of MLE on the growth, yield characteristics and water use efficiency (WUE), physio-biochemical attributes, and leaf anatomy of squash plants exposed to DI stress was assessed. MLE-treated plants exposed to DI had higher growth and yield characteristics, harvest index (HI),WUE, chlorophyll fluorescence ( F v /F m and PI), photosynthetic pigments, soluble sugars and free proline, leaf anatomy, relative water content (RWC%) and membrane stability index (MSI%) and had lower electrolyte leakage (EL%) compared to MLE-untreated plants. Application of 3% MLE was effective in alleviating damages of drought stresses in squash plants by maintaining higher RWC, WUE, and osmoprotectants, and lower EL. [ABSTRACT FROM AUTHOR]

Fatty acids (FA) of pumpkin seed oil have a wide range of applications in treating prostate and skin cancers. The loading of these materials on magnetic nanoparticles (MNPs) constitutes a new approach to drug delivery systems. In this study, a safe and controllable process for adsorption of FAs from pumpkin seed oil on iron oxide nanoparticles has been presented. To extract and adsorb FAs from seed oil, the saponification reaction of oil was carried out along with the innovated hydrothermal method using the evaporation technique in the presence of MNPs. The impact of various parameters such as temperature, distilled water volume, ratio of FA to iron moles, the effect of adsorption process time on FA adsorption value and MNP size were investigated experimentally. Afterward, the optimum conditions to achieve high adsorption efficiency and low particle size were investigated using a novel hybrid SA-LOOCV-GRBF neural network modeling. This method estimated parameters of generalized radial basis function (GRBF) with simulated annealing (SA) optimization and leave one out cross validation (LOOCV) technique. Using LOOCV criteria and SA, the algorithm generated a structure distinct from other methods and achieved optimum parameters without gradient method. It provided a function that was useful for experimental optimization. The results of modeling showed that this new approach could successfully predict experimental results. Under optimum conditions, an estimated particle size of about 20 nm was achieved using TEM analysis with spherical morphology. The estimated FA thickness on the surface of nanoparticles was about 5 nm. Fourier transform infrared spectroscopy (FTIR) confirmed the successful formation of FA layers around nanoparticles. Moreover, zeta potential and vibrating sample magnetometer (VSM) showed that particles had super paramagnetic property with a net charge of −52 mv, which was suitable for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

The genetic basis of fruit size and shape was investigated for the first time in Cucurbita species and genetic loci associated with fruit morphology have been identified. Although extensive genomic resources are available at present for tomato ( Solanum lycopersicum ), cucumber ( Cucumis sativus ), melon ( Cucumis melo ) and watermelon ( Citrullus lanatus ), genomic databases for Cucurbita species are limited. Recently, our group reported the generation of pumpkin ( Cucurbita pepo ) transcriptome databases from two contrasting cultivars with extreme fruit sizes. In the current study we used these databases to perform comparative transcriptome analysis in order to identify genes with potential roles in fruit morphology and fruit size. Differential Gene Expression (DGE) analysis between cv. ‘Munchkin’ (small-fruit) and cv. ‘Big Moose’ (large-fruit) revealed a variety of candidate genes associated with fruit morphology with significant differences in gene expression between the two cultivars. In addition, we have set the framework for generating EST-SSR markers, which discriminate different C. pepo cultivars and show transferability to related Cucurbitaceae species. The results of the present study will contribute to both further understanding the molecular mechanisms regulating fruit morphology and furthermore identifying the factors that determine fruit size. Moreover, they may lead to the development of molecular marker tools for selecting genotypes with desired morphological traits. [ABSTRACT FROM AUTHOR]

Carbon coils have many significant technological applications; however, most of them were fabricated using either expensive apparatus or complicated procedures. Herein, a versatile and simple method was used for fabricating valuable single-helix carbon microcoils (SHCMs) by Fe(III)-osmotically induced shape transformation of zucchini ( Cucurbita pepo L.). This versatile strategy allowed to readily reach high surface area (365 m 2 g −1 ), large pore volume (0.24 cm 3 g −1 ) and a narrow average mesoporous size of 5.5 nm via a combined impregnation and hydrothermal carbonization process, and to achieve uniform SHCMs in a reasonable system. In addition, the SHCMs showed excellent performance in antibacterial property and the clearance of chloramphenicol, which should be a promising candidate for efficient adsorbent in water purification. The equilibrium data were well fitted to the Langmuir isotherm model with a maximal adsorption capacity of 124.32 mg g −1 at ambient temperature. The antibacterial mechanisms was also explored. The findings revealed that the Fe(III)-osmotically induced transformation is a potential route for large-scale preparation of SHCMs from appropriate biomass precursors. [ABSTRACT FROM AUTHOR]

The aetiology of squash silverleaf (SSL) induced by the infestation of Bemisia tabaci (Gennadius) ‘biotype’ B ( B. tabaci -B) is poorly understood. To help to find out how B. tabaci destroys Cucurbita pepo L. and induces SSL, changes induced by SSL and responses of C. pepo to B. tabaci -B infestation were studied by comparing chlorophyll fluorescence parameters and biochemical, morphological and anatomical aspects of grade 0–4 SSL leaves. The results showed that chlorophyll contents decreased and the chlorophyll a/b ratio increased with the increase of silvered leaf, which indicated that the decrease of chlorophyll contents led to silvered leaf. Anatomical observation showed that B. tabaci -B infestation changed the shape and arrangement of lower epidermis cells and spongy mesophyll cells. Moreover, air spaces appeared between upper epidermis and palisade tissue and in spongy tissue, which might be the cause of the increase in leaf thickness. Additionally, the altering of former spaces light reflection was another reason for leaf silvering. As response to B. tabaci -B infestation, the content of soluble proteins and soluble sugar decreased, and the content of Malondialdehyde (MDA) increased. Pearson correlation showed a significant correlation between fluorescence parameters (except α) and the other parameters measured in this study. The result also suggested that chlorophyll fluorescence can be widely used in field studies as an early diagnostic measure of stress in plant caused by adverse environmental conditions, especially by insect pests. [ABSTRACT FROM AUTHOR]

• Applying selenium (Se) as foliar nourishment attenuated salt stress in Cucurbita pepo. • Antioxidant capacity was maximized in salt-stressed Cucurbita pepo by Se application. • Oxidative stress and its consequences were minimized in salt-stressed Cucurbita pepo by Se application. • Gene expression induced enzyme activities were maximized in salt-stressed Cucurbita pepo by Se application. • The maximized antioxidant capacity and minimized oxidative stress reflected maximized productivity of salt-stressed Cucurbita pepo. Salinity dramatically decreases the yield of most agricultural plants by causing osmotic and ionic stress that negatively impacts plant growth and development. As previously documented, selenium (Se), as a serviceable trace element, alleviates abiotic stress impacts, particularly salinity, on several plant species. This work was done perfectly to evaluate the impact of leaf feeding with Se on indicators of salt tolerance in Cucurbita pepo. Salt stress (9.45 dS m−1) noticeably raised electrolyte leakage (EL) and malondialdehyde (MDA) owing to the rise in the examined markers of oxidative stress like hydrogen peroxide (H 2 O 2) and superoxide (O 2 •‒), and Na+ content. As a result, the contents of osmo-regulators and non-enzymatic antioxidants, activities of enzymatic antioxidants, and enzyme gene expressions were markedly increased. The salinity-induced oxidative stress noticeably diminished growth features, membrane stability index (MSI), relative water content (RWC), K +/Na+ ratio, pigment, nutrient, and Se contents. Fruit yield and fruit content of Se and vitamin C also diminished. However, the application of Se noticeably decreased LI and MDA owing to the minimization in the levels of O 2 •‒, H 2 O 2 , and Na+. This positive outcome was connected with a further rise in the levels and activities of osmo-regulators, the defensive system components, and enzymatic gene expressions, which were positively reflected in the growth features, RWC, MSI, K +/Na+ ratio, pigment, nutrient, and Se contents, as well as fruit yield and fruit quality. Our results indicate that 15 g Se applied per hectare attenuated the negative impacts of salt stress in C. pepo via various mechanisms such as minimization of reactive oxygen species (ROS; O 2 •‒ and H 2 O 2) and Na+ contents, and improvement of leaf integrity, nutrient homeostasis, photosynthetic capacity, osmoregulators and antioxidant enzyme activities, enzymatic gene expressions, and the regulation of Na+ homeostasis. Graphical Abstract shows the enhancing effect of exogenously applied selenium on the hazardous impact of salt stress in Cucurbita pepo. [Display omitted] [ABSTRACT FROM AUTHOR]

• Nano-K maximized salt-stressed squash plant productivity and yield quality. • Nano-K catalyzed more antioxidant activities, attenuating damage of oxidative stress markers. • Nano-K efficiently improved photosynthesis and plant integrity under salt stress. • Nano-K efficiently restored the nutrients of salt-stressed squash plants. • Nano-K efficiently improved antioxidant enzymes and their gene expression in salt - stressed squash plants. To explore the reinforcing effects of nano-potassium fertilizer (nano-K) on growth, yield and quality, physio-biochemical responses, antioxidant defense systems, antioxidant gene expressions, and nutrients of salt-stressed squash plants, field experiments were performed using normal (EC = 2.34 dS m−1) and saline (EC = 9.38 dS m−1) soils during the 2021 and 2022 seasons. The traditional recommended K at full dose (TRK 100) or half dose (TRK 50) was used in both soils. Salinity and/or TRK 50 significantly decreased photosynthetic pigment contents (by 8.7−22.5%), photosynthetic efficiency (by 6.0−10.9%), relative water content (RWC by 5.0−5.1%), membrane stability index (MSI by 7.2−7.4%), nutrient contents (by 28.4−48.2%), K+/Na+ ratio (by 66.4−67.1%), which contributed to the decrease in growth (by 12.2−25.8%) and yield traits (by 4.2−28.5%), and fruit quality (by 8.5−19.7%) due to an increment of oxidative stress biomarker (O 2 •‒ by 32.4−52.9% and H 2 O 2 30.4−57.1%) levels, electrolyte leakage (EL by 23.3−24.5%), malondialdehyde (MDA by 71.4−77.6%), and Na+ (by 55.5−56.9%). Under stress in both soils, foliar-applied 0.50 g nano-K L−1 suppressed the levels of O 2 •‒, H 2 O 2 , MDA, EL, and Na+, while noticeably increased photosynthetic pigment contents, photosynthetic efficiency, RWC, MSI, nutrient contents, K+/Na+ ratio, which were positively reflected in growth and yield traits, and fruit quality due to increased osmoprotectant and low-molecular-weight antioxidant contents, antioxidant enzyme activities and enzymatic gene expressions. Therefore, our findings recommend using nano-K as an effective strategy to promote antioxidant and photosynthetic machineries, minimize oxidative stress biomarkers and Na+ levels, boost tolerance to salt stress, and improve squash yield and yield quality under salt stress. Shows the reinforcing effect of nano-K on the antioxidant defense system reflecting the increased yield and quality of salt-stressed squash plants [Display omitted] [ABSTRACT FROM AUTHOR]

The increasing use of graphene-related materials (GRMs) in everyday-life products raises concerns for their possible release into the environment and consequent impact on organisms. GRMs have widely varying effects on plants and, according to recent evidences, graphene oxide (GO) has the potential to interfere with the sexual reproduction owing to its acidic properties and production residues. Here, stigmas of the model plant Cucurbita pepo (summer squash) were subjected to simulated dry depositions of GO and GO purified from production residues (PGO). Stigmas were then hand-pollinated and GRM deposition was checked by ESEM and confocal microscopy. Analysis of stigma integrity, pH homeostasis and pollen-stigma interactions did not reveal negative effects. Fruit and seed production were not affected, but GO depositions of 22.1 ± 7.2 ng mm−2 affected the normal development of seeds, decreasing seed dimensions, seed germination and germination speed. The elemental analysis revealed that GO has significant quantities of production residues, such as strong acids and oxidants, while PGO has only traces, which justifies the differences observed in the effects caused by the two materials. Our results show that GO depositions of up to 11.1 ± 3.6 ng mm−2, which fall within the variation range of total dry particulate matter depositions reported in the literature, are safe for reproduction of C. pepo. This is the first "safety" limit ever recorded for depositions of "out-of-the-box" GO concerning the reproduction of a seed plant. If confirmed for wind-pollinated species, it might be considered for policymaking of GRMs emissions in the air. [Display omitted] • Environmentally relevant depositions of Graphene Oxide (GO) on flowers were applied. • Neither pollen adhesion nor fruit formation were significantly affected. • Seed development and germination were affected only at 22.1 ± 7.2 ng mm−2 • The effects were caused by the residues of the production process still bound to GO. • The first safety limits for a seed plant concerning "out-of-the-box" GO are given. [ABSTRACT FROM AUTHOR]

Cucurbita pepo is the most economically important species of the genus Cucurbita (Cucurbitaceae). Its edible-fruited cultivated germplasm has been grouped into eight morphotypes (cultivar-groups) divided between two subspecies: pepo and ovifera. In this work, 93 accessions representative of all morphotypes were grown to investigate their genetic variability and to evaluate their potential for production and suitability of male flowers to be used as an Italian frozen food specialty. Results provid the first indications of a plant ideotype for such use. Principal coordinates analysis (PCoA) with nine SSR markers clearly separated the two subspecies, and yielded information on genetically similar vs distant genotypes to be used for parent choice in breeding programs. Analysis of morphological data allowed identification of seven accessions that met all the criteria for the specialty use of male flowers for the frozen food industry: production of many flowers, corolla length of 6–8 cm; and reduced spininess of the foliage. When accessions representing different morphotypes were compared for average male corolla length and average number of male flowers per plant, some accessions of the Pumpkin cultivar-group were observed to be the most suitable for the purpose. Overall, the information collected in the present work is a starting point for exploitation of C. pepo biodiversity in future breeding programs aimed at the production of male flowers for use by the frozen-food industry. [ABSTRACT FROM AUTHOR]

Cavitation-accelerated aqueous enzymatic extraction (CAEE) of seed oil from Cucurbita pepo was performed. An enzyme cocktail comprised of cellulose, pectinase and proteinase can work synergistically in releasing the oil. The CAEE extraction conditions were optimized by a Plackett-Burman design followed by a central composite methodology. A maximal extraction yield of 58.06% was achieved under optimal conditions of vacuum degree −0.07, enzyme amount 1.05% and extraction time 69 min. As compared to soxhlet extraction (SE)-derived oil, CAEE-derived oil exhibited similar physical properties and better oxidation stability. In addition, chemical composition analyzing showed that the content of linoleic acid obtained by CAEE (47.67%) was higher than that of SE (44.51%). Moreover, the IC 50 of oil obtained by CAEE and SE, as measured by α-amylase inhibition assay, were 40.68 μg/mL and 45.46 μg/mL. All results suggest that CAEE represents an excellent alternative protocol for production of oil from oil-bearing materials. [ABSTRACT FROM AUTHOR]

Pumpkin seed protein isolate (PSPI) was enzymatically hydrolyzed by alcalase and pepsin to obtain H1 and H2 hydrolysates, respectively. Influence of enzymatic hydrolysis on solubility, interfacial and emulsifying properties of PSPI was investigated as a function of pH (3–8) and ionic strength (0–1 mol/dm 3 NaCl). Solubility of PSPI was lowest at pI = 5. Solubility of both hydrolysates was higher than solubility of PSPI, especially at pH close to pI. Increase in ionic strength brings about salting–in or salting–out effect in PSPI, H1, and H2 solutions, depending on pH of the solutions. Tensiometric investigation showed that PSPI, H1 and H2 adsorb at both air/protein solution and oil/protein solution interfaces regardless of pH and ionic strength. 20% emulsions of sunflower oil in a continuous phase consisting of 1 g/100 cm 3 PSPI, H1 or H2 solutions at pH 3, 5 and 8, and ionic strengths of 0 and 0.5 mol/dm 3 NaCl were prepared. Emulsifying performance of proteins depended on pH and ionic strength. PSPI failed to stabilize emulsions against droplet coalescence at pI = 5 regardless of ionic strength, and at pH 3 with 0.5 mol/dm 3 NaCl, while both hydrolysates, H1 and H2, successfully stabilized emulsions no matter of pH and ionic strength. Smallest mean droplet diameter in emulsions of increased ionic strength (0.5 mol/dm 3 ) were obtained when they were stabilized with H2, H1, and both PSPI and H1 at pH 3, 5, and 8, respectively. All emulsions were susceptible to creaming instability. [ABSTRACT FROM AUTHOR]

The effects of amplitude and time of ultrasound-assisted extraction on the physicochemical properties and the fatty acid profile of pumpkin seed oil ( Cucurbita pepo ) were evaluated. Ultrasound time (5–30 min) and the response variables amplitude (25–100%), extraction yield, efficiency, oxidative stability in terms of the free fatty acids (FFA) of the plant design comprising two independent experiments variables, peroxide (PV), p -anisidine (AV), totox value (TV) and the fatty acid profile were evaluated. The results were analyzed by multiple linear regression. The time and amplitude showed significant differences ( P < 0.05) for all variables. The highest yield of extraction was achieved at 5 min and amplitude of 62.5% (62%). However, the optimal ultrasound-assisted extraction conditions were as follows: ultrasound time of 26.34 min and amplitude of 89.02%. All extracts showed low FFA (2.75–4.93% oleic acid), PV (1.67–4.68 meq/kg), AV (1.94–3.69) and TV (6.25–12.55) values. The main fatty acids in all the extracts were oleic and linoleic acid. Therefore, ultrasound-assisted oil extraction had increased performance and reduced extraction time without affecting the oil quality. [ABSTRACT FROM AUTHOR]

Endophytic bacteria often have beneficial effects on their host plants that can be exploited for bioremediation applications but, according to the literature, only 0.001–1% of all endophytic microbes should be cultivable. This study compared the cultivated endophytic communities of the roots and shoots of Cucurbita pepo with the total endophytic communities as determined by cultivation-dependent techniques and 454 pyrosequencing. The ten most abundant taxa of the total communities aligned well with the cultivated taxa; however, the abundance of these taxa in the two communities differed greatly. Enterobacter showed very low presence in the total communities, whereas they were dominantly present in the cultivated communities. Although Rhizobium dominated in total root and shoot communities, it was poorly cultivable and even then only in growth media containing plant extract. Since endophytes likely contribute to plant-growth promotion, cultivated bacterial strains were tested for their plant-growth promoting capabilities, and the results were correlated with their abundance in the total community. Bacillus and Pseudomonas showed promising results when considering cultivability, abundance in the total community and plant-growth promoting capability. This study demonstrated that, although a limited number of bacterial genera were cultivable, current cultivation-dependent techniques may be sufficient for further isolation and inoculation experiments that aim to improve phytoremediation efficiency. [ABSTRACT FROM AUTHOR]

2,2-bis(p-chlorophenyl)-1,1-dichloro-ethylene (DDE) is the most abundant and persistent degradation product of the pesticide 2,2-bis( p -chlorophenyl)-1,1,1-trichloroethane (DDT) and is encountered in contaminated soils worldwide. Both DDE and DDT are classified as Persistent Organic Pollutants (POPs) due to their high hydrophobicity and potential for bioaccumulation and biomagnification in the food chain. Zucchini ( Cucurbita pepo ssp. pepo ) has been shown to accumulate high concentrations of DDE and other POPs and has been proposed as a phytoremediation tool for contaminated soils. The endophytic bacteria associated with this plant may play an important role in the remedial process. Therefore, this research focuses on changes in endophytic bacterial communities caused by the exposure of C. pepo to DDE. The total bacterial community was investigated using cultivation-independent 454 pyrosequencing, while the cultivable community was identified using cultivation-dependent isolation procedures. For both procedures, increasing numbers of endophytic bacteria, as well as higher diversities of genera were observed when plants were exposed to DDE. Several bacterial genera such as Stenotrophomonas sp. and Sphingomonas sp. showed higher abundance when DDE was present, while, for example Pseudomonas sp. showed a significantly lower abundance in the presence of DDE. These findings suggest tolerance of different bacterial strains to DDE, which might be incorporated in further investigations to optimize phytoremediation with the possible use of DDE-degrading endophytes. [ABSTRACT FROM AUTHOR]

The Cucurbitaceae family accumulates dioxin-like compounds in its fruits. We previously showed that A20/AN1 zinc finger protein (ZFP) genes were highly expressed in the zucchini (Cucurbita pepo) subspecies pepo , which accumulates dioxin-like compounds at high concentrations. Transgenic tobacco (Nicotiana tabacum) plants overexpressing A20/AN1 ZFP genes show accumulation of dioxin-like compounds in their upper parts. However, the mechanisms underlying the accumulation of dioxin-like compounds regulated by the A20/AN1 ZFPs remain unclear. Here, we show that A20/AN1 ZFPs positively regulate the expression of the major latex-like protein (MLP) and its homolog genes in N. tabacum and C. pepo. MLPs are involved in the transport of dioxin-like compounds from the roots to the upper parts of C. pepo. Overexpression of A20/AN1 ZFP genes in N. tabacum leads to the upregulation of pathogenesis-related protein class-10 genes with the binding ability toward dioxin-like compounds. Our results demonstrated that A20/AN1 ZFPs upregulate MLP and its homolog genes in N. tabacum and C. pepo , resulting in the accumulation of dioxin-like compounds. [Display omitted] • The Cucurbitaceae family accumulates dioxin-like compounds in their fruits. • Major latex-like proteins (MLPs) transport dioxin-like compounds in Cucurbita pepo. • A20/AN1 zinc-finger protein (ZFP) genes are expressing in C. pepo. • A20/AN1 ZFPs upregulate MLP genes in C. pepo. • A20/AN1 ZFPs promoted the transport of dioxin-like compounds via MLPs. [ABSTRACT FROM AUTHOR]

• Histology revealed a collapse of 5 layered structure in the hull-less seed coat. • Protein, amino acid, lipid and starch play no role in producing the hull-less trait. • The cell wall components decreased after 20 DPA in the hull-less seed coats. • A hull-less mutation reduced the lignin deposition in the pumpkin seed coat. • All deviations from the normal pattern of development in seeds occurred at 20 DPA. Pumpkin seeds have great therapeutic value but remain underutilized due to its hulled character. However, a hull-less mutation revolutionized the fate of pumpkin seeds in the oil industry by omitting the decortication process. Therefore, the present research was conducted to understand the histological and physiological changes caused by this mutation in the developing seeds of pumpkin that produces the desired hull-less phenotype. In scanning electronic microscopy, a distinct five cell layered structure was observed in the seed coat of hulled (PCK-1) genotype, which was collapsed in the partially hulled (WT-2046) and the hull-less (PMK-1) genotypes. Also the seed coat layers increased continuously in hulled genotype until maturity; however, these declined after 20 DPA in the other two genotypes. Physiological studies revealed that protein, amino acid, starch and lipid content followed the same trend, but the wall components (pectin, hemicelulose, cellulose and lignin) differed significantly amongst the genotypes. The wall components increased continuously until maturity in the hulled genotype, but decreased after 20 DPA in the partially hulled and hull-less genotypes. Further, the correlation, PCA and cluster analysis also reinforced that the wall components especially the lignin was responsible in maintaining the seed coat structure in the hulled genotype and its reduction poses as a reason for the collapsed seed coat in other two genotypes. Lignin reduction was noticed at 20 DPA in the hull-less genotype and therefore, this stage can be used to identify the gene responsible for lignin synthesis in the seed coats. [ABSTRACT FROM AUTHOR]

The accessions variability in crop species is crucial for crop improvement and consequently enables the development of more new valuable agricultural products. This study aimed to evaluate the ascorbic acid (AA), chlorophyll a (Chl-A), chlorophyll b (Chl-B), total phenolic compounds (TPC) as well as dry matter (DM) in different tissues (exocarp and mesocarp) of Cucurbita pepo fruits belonging to 27 morphologically diverse germplasm accessions (14 traditional accessions and 13 commercial hybrids from different countries). DM content ranged from 4.2 to 11.76%, while natural pigments were between 5.85 and 2602.2 μg/g DW (corresponding to Chl-B and Chl-A, respectively). Other antioxidant compounds registered higher values, 0.47–1.29 mg/g DW for AA and 1.98–5.49 mg/g DW for TPC. Additionally, pattern-recognition techniques including distribution, principal component analysis (PCA) and dendogram cluster analysis were used to compare accessions. PCA revealed that the first two components represented 76% and 84% of the total variability in exocarp and mesocarp tissues, respectively; while clusters regrouped those accessions with greater similarity. Exocarp samples exhibited a significantly higher content in all compounds studied, thus positively suggesting the beneficial consumption of fruit peel. This work also highlights the potential contribution of ‘zucchini’ morphotype to dietary intake requirements, being moderate in ‘vegetable marrow’ and ‘pumpkin’. Accessions rich in AA, Chl-A, Chl-B and TPC like those namely Ac-2, Ac-8, Ac-23 and Ac-27 could be exploited as potential donors for novel variety development in future breeding programmes. [ABSTRACT FROM AUTHOR]