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Soil salinity is a major nutritional challenge with poor agriculture production characterized by high sodium (Na+) ions in the soil. Zinc oxide nanoparticles (ZnO NPs) and biochar have received attention as a sustainable strategy to reduce biotic and abiotic stress. However, there is a lack of information regarding the incorporation of ZnO NPs with biochar to ameliorate the salinity stress (0, 50,100 mM). Therefore, the current study aimed to investigate the potentials of ZnO NPs application (priming and foliar) alone and with a combination of biochar on the growth and nutrient availability of spinach plants under salinity stress. Results demonstrated that salinity stress at a higher rate (100 mM) showed maximum growth retardation by inducing oxidative stress, resulted in reduced photosynthetic rate and nutrient availability. ZnO NPs (priming and foliar) alone enhanced growth, chlorophyll contents and gas exchange parameters by improving the antioxidant enzymes activity of spinach under salinity stress. While, a significant and more pronounced effect was observed at combined treatments of ZnO NPs with biochar amendment. More importantly, ZnO NPs foliar application with biochar significantly reduced the Na+ contents in root 57.69%, and leaves 61.27% of spinach as compared to the respective control. Furthermore, higher nutrient contents were also found at the combined treatment of ZnO NPs foliar application with biochar. Overall, ZnO NPs combined application with biochar proved to be an efficient and sustainable strategy to alleviate salinity stress and improve crop nutritional quality under salinity stress. We inferred that ZnO NPs foliar application with a combination of biochar is more effectual in improving crop nutritional status and salinity mitigation than priming treatments with a combination of biochar.

A central goal of photoprotective energy dissipation processes is the regulation of singlet oxygen (1O2*) and reactive oxygen species in the photosynthetic apparatus. Despite the involvement of 1O2* in photodamage and cell signaling, few studies directly correlate 1O2* formation to nonphotochemical quenching (NPQ) or lack thereof. Here, we combine spin-trapping electron paramagnetic resonance (EPR) and time-resolved fluorescence spectroscopies to track in real time the involvement of 1O2* during photoprotection in plant thylakoid membranes. The EPR spin-trapping method for detection of 1O2* was first optimized for photosensitization in dye-based chemical systems and then used to establish methods for monitoring the temporal dynamics of 1O2* in chlorophyll-containing photosynthetic membranes. We find that the apparent 1O2* concentration in membranes changes throughout a 1 h period of continuous illumination. During an initial response to high light intensity, the concentration of 1O2* decreased in parallel with a decrease in the chlorophyll fluorescence lifetime via NPQ. Treatment of membranes with nigericin, an uncoupler of the transmembrane proton gradient, delayed the activation of NPQ and the associated quenching of 1O2* during high light. Upon saturation of NPQ, the concentration of 1O2* increased in both untreated and nigericin-treated membranes, reflecting the utility of excess energy dissipation in mitigating photooxidative stress in the short term (i.e., the initial ∼10 min of high light).

Objective: Cucumber mosaic virus (CMV) is a significant pathogen causing quality loss in spinach. Although host genetic resistance is the primary method of managing CMV infection in this crop, CMV resistance genes are not widely utilized in spinach breeding programs as the genetic and molecular mechanisms underlying resistance are not yet fully understood. CMV infections were therefore studied in different lines of spinach plants, and their progeny, to develop a model of the genetic basis of CMV resistance. Results: Visual observations and RT-PCR assays revealed that three monoecious lines (03-258, 03-263, and 03-336) were susceptible to CMV, while three traditional resistant cultivars and a near-isogenic line (NIL-M) exhibited resistance. A dioecious line (03–009) consisted of susceptible and resistant plants. Notably, resistant plants did not exhibit the lesions typical of the hypersensitive response. Genetic analysis of progeny from the cross NIL-M × 03-336 indicated that a single dominant allele (designated SRCm1, standing for Spinach Resistance to CMV 1) controlled CMV resistance; analysis of sib-cross progeny populations derived from line 03–009 supported this conclusion. These results offer a valuable model for CMV resistance in spinach and will enhance future breeding programs. [ABSTRACT FROM AUTHOR]

Soil salinity is a worldwide issue and a major threat to global food security. Salinity tolerance is a complex mechanism that is conferred by numerous molecular, physiological, and biochemical traits. Of critical importance are plant's ability to regulate redox balance without compromising reactive oxygen species (ROS) signalling and maintain cytosolic ion homeostasis. In this study, the mechanistic basis of K+ retention ability in leaf mesophyll (an important but highly sensitive plant tissue) was compared between halophytic quinoa and glycophytic spinach. Phenotypic data showed quinoa outperformed spinach under 100 to 500 mmol L-1 NaCl salinity. The major difference behind this differential salinity sensitivity was a differential K+ uptake in leaf mesophyll. Electrophysiological and molecular experiments revealed that a superior ability of mesophyll K+ retention in quinoa was conferred by three complementary mechanisms: (i) an intrinsically lower H+-ATPase activity in quinoa (potentially as an energy saving strategy); (ii) reduced sensitivity of K+ transporters to ROS; and (iii) increased sensitivity of ROS-inducible Ca2+- permeable channels. Moreover, the sensitivity of K+-transport systems to ROS was further examined in NaCl-acclimated quinoa and spinach plants. The key factors differentiating between K+ retention in acclimated leaf mesophyll was associated with the reduced sensitivity and gene expression of K+-permeable outward rectifying channel (GORK), Arabidopsis potassium transporter 1 (AKT1), and high affinity potassium transporter 5 (HAK5) to additional NaCl and ROS stress, along with the upregulation of ROS scavenging system. Taken together, our results showed that the tissue-specific and ROS-specific regulation of K+ retention are important for conferring salinity tolerant at least in the halophyte quinoa. [ABSTRACT FROM AUTHOR]

Abstract Objective Cucumber mosaic virus (CMV) is a significant pathogen causing quality loss in spinach. Although host genetic resistance is the primary method of managing CMV infection in this crop, CMV resistance genes are not widely utilized in spinach breeding programs as the genetic and molecular mechanisms underlying resistance are not yet fully understood. CMV infections were therefore studied in different lines of spinach plants, and their progeny, to develop a model of the genetic basis of CMV resistance. Results Visual observations and RT-PCR assays revealed that three monoecious lines (03-258, 03-263, and 03-336) were susceptible to CMV, while three traditional resistant cultivars and a near-isogenic line (NIL-M) exhibited resistance. A dioecious line (03–009) consisted of susceptible and resistant plants. Notably, resistant plants did not exhibit the lesions typical of the hypersensitive response. Genetic analysis of progeny from the cross NIL-M × 03-336 indicated that a single dominant allele (designated SRCm1, standing for Spinach Resistance to CMV 1) controlled CMV resistance; analysis of sib-cross progeny populations derived from line 03–009 supported this conclusion. These results offer a valuable model for CMV resistance in spinach and will enhance future breeding programs.

Soil salinity is a worldwide issue and a major threat to global food security. Salinity tolerance is a complex mechanism that is conferred by numerous molecular, physiological, and biochemical traits. Of critical importance are plant’s ability to regulate redox balance without compromising reactive oxygen species (ROS) signalling and maintain cytosolic ion homeostasis. In this study, the mechanistic basis of K+ retention ability in leaf mesophyll (an important but highly sensitive plant tissue) was compared between halophytic quinoa and glycophytic spinach. Phenotypic data showed quinoa outperformed spinach under 100 to 500 mmol L−1 NaCl salinity. The major difference behind this differential salinity sensitivity was a differential K+ uptake in leaf mesophyll. Electrophysiological and molecular experiments revealed that a superior ability of mesophyll K+ retention in quinoa was conferred by three complementary mechanisms: (i) an intrinsically lower H+-ATPase activity in quinoa (potentially as an energy saving strategy); (ii) reduced sensitivity of K+ transporters to ROS; and (iii) increased sensitivity of ROS-inducible Ca2+-permeable channels. Moreover, the sensitivity of K+-transport systems to ROS was further examined in NaCl-acclimated quinoa and spinach plants. The key factors differentiating between K+ retention in acclimated leaf mesophyll was associated with the reduced sensitivity and gene expression of K+-permeable outward rectifying channel (GORK), Arabidopsis potassium transporter 1 (AKT1), and high affinity potassium transporter 5 (HAK5) to additional NaCl and ROS stress, along with the upregulation of ROS scavenging system. Taken together, our results showed that the tissue-specific and ROS-specific regulation of K+ retention are important for conferring salinity tolerant at least in the halophyte quinoa.

We developed a contemporary cardioprotective medication using silver nanoparticles (AgNPs) loaded with Spinacia oleracea to treat isoproterenol (ISO)-induced myocardial infarction in mice, focusing on the PPAR-γ/NF-κB pathway. The physicochemical techniques, such as Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, ultraviolet–visible spectroscopy, and energy dispersive X-ray analysis, were employed to characterize the AgNPs. In the in vivo experiment, myocardial infarction was induced in mice by administering ISO subcutaneously at a dose of 40 mg/kg every 12 h for a total of three times. The mice were divided into five groups in a random manner: (1 and 2) ISO + AgNPs at varying doses (10 and 20 μg/mL) and time points; (3) ISO; and (4) control. Following the treatment, cardiac function was assessed through electrocardiogram, as well as biochemical and histochemical analyses. In the study, we examined the inflammatory reactions and cell death in human coronary artery endothelial cells exposed to lipopolysaccharide (LPS). The PPAR-γ/NF-κB activation by LPS and the resulting cytokine production were checked using real-time PCR and western blot techniques. The typical ST segment depression in myocardial infarction mice is significantly inhibited by the administration of AgNPs. Additionally, the treatment with AgNPs leads to a significant improvement in ventricular wall infarction, a decrease in mortality rate, and inhibition of myocardial injury marker levels. Furthermore, the application of AgNPs resulted in a decrease in the inflammatory environment within the hearts of mice with myocardial infarction. This effectively prevented the increase in TNF-α, IL-1β, and IL-6. The gene expression normalization of PPAR-γ/NF-κB/IκB-α/IKKα/β and PPAR-γ phosphorylation could potentially be linked to the advantageous impacts of AgNPs. In the context of an in vitro experiment, the administration of AgNPs demonstrated a notable decrease in cell death and inflammation cytokines expression inhibition. The myocardial infarction mice in the pre + post-ISO group appear to experience more noticeable cardioprotective effects from the treatment with AgNPs than those in the post-ISO group. Our research findings demonstrate that AgNPs possess cardioprotective efficacies in ISO-induced myocardial infarction. This beneficial effect may be attributed to the PPAR-γ activation and the NF-κB signaling inhibition. Consequently, our study presents a novel remedial approach for myocardial infarction treatment in clinical settings.

Diclofenac, often detected in environmental samples, poses a potential hazard to the aquatic environment. The present study aimed to understand the effect of this drug on photosynthetic apparatus, which is a little-known aspect of its phytotoxicity. Chloroplasts and thylakoids isolated from spinach (Spinacia oleracea) were used for this study and treated with various concentrations of diclofenac (from 125 to 4000 μM). The parameters of chlorophyll a fluorescence (the OJIP test) as measurements for both the intact chloroplasts and the thylakoid membranes revealed that isolated thylakoids showed greater sensitivity to the drug than chloroplasts. The relatively high concentration of diclofenac that is required to inhibit chloroplast and thylakoid functions suggests a narcotic effect of that drug on photosynthetic membranes, rather than a specific interaction with a particular element of the electron transport chain. Using confocal microscopy, we confirmed the degradation of the chloroplast structure after DCF treatment, which has not been previously reported in the literature. In conclusion, it can be assumed that diclofenac's action originated from a non-specific interaction with photosynthetic membranes, leading to the disruption in the function of the electron transport chain. This, in turn, decreases the efficiency of photosynthesis, transforming part of the PSII reaction centers into heat sinks and enhancing non-photochemical energy dissipation. [ABSTRACT FROM AUTHOR]

Spinach (Spinacia oleracea L.), a valuable crop, suffers greatly from salt stress. This study investigates the potential of green silver nanoparticles (Ag-NPs) synthesized using Aloe vera extract to relieve the harmful effects of salt stress on spinach seed germination and growth. The experiment evaluated various seed germination and plant growth characteristics of spinach cultivar Viroflay RZ under five Ag-NP concentrations (0, 20, 40, 80, and 100 ppm) and four salinity levels (0, 50, 100, and 150 mM NaCl) in a controlled laboratory setting. This studymeasured seed germination percentage, rate and relative germination, vigor indices, plant height, root length, shoot and root dry weight, and chlorophyll content. Data analysis revealed that salinity stress significantly inhibited seed germination and all other studied parameters, especially at higher salt concentrations. The impact of green Ag-NPs on these traits varied considerably under salt stress. A complex statistical model showed a non-linear relationship between Ag-NP concentration and its effect, with an optimal concentration potentially alleviating the negative effects of salt stress. The study suggests that pre-treating spinach seeds with green Ag-NPs at an optimized concentration might enhance their tolerance to salt stress, potentially improving germination and growth under saline conditions. This research promotes using eco-friendly nanotechnology to mitigate the detrimental effects of salinity on agricultural productivity. [ABSTRACT FROM AUTHOR]

Ribulose‐1,5‐bisphosphate carboxylase/oxygenase (RuBisCO) is the enzyme responsible for the first step of carbon dioxide (CO2) fixation in plants, which proceeds via the carboxylation of ribulose 1,5‐biphosphate. Because of the enormous importance of this reaction in agriculture and the environment, there is considerable interest in the mechanism of fixation of CO2 by RuBisCO. Here, a serial synchrotron crystallography structure of spinach RuBisCO is reported at 2.3 Å resolution. This structure is consistent with earlier single‐crystal X‐ray structures of this enzyme and the results are a good starting point for a further push towards time‐resolved serial synchrotron crystallography in order to better understand the mechanism of the reaction. [ABSTRACT FROM AUTHOR]

Spinach has been suggested as a potential rotation crop for increasing crop yield by enhancing beneficial fungal microbes in continuous monocropping. However, no research on the use of spinach as a green manure has been reported. Thus, we tested the effects of spinach and Korean mustard cultivars (green and red mustards) (10 g pot -1) as green manure on soil chemical properties, pepper productivity, and soil microbiome of long-year pepper-monocropped soil. Spinach improved the soil nutrition (e.g., pH, SOM, TN, NH4+, and K), weed suppression, and pepper growth. Spinach had by far the highest fruit yield, over 100% pepper fruit yield increment over the mustard green manures and control. Our study showed that the major influencing factors to cause a shift in both bacterial and fungal community assemblies were soil pH, TC TN, and K. Following green manure amendment Bacillota, especially Clostridium, Bacillus and Sedimentibacter, were enriched, whereas Chloroflexi and Acidobacteriota were reduced. In addition, spinach highly reduced the abundance of Leotiomycetes and Fusarium but enriched Papiliotrema. FAPROTAX and FUNGuild analysis revealed that predicted functional profiles of bacterial and fungal communities in spinach-amended soil were changed. Spinach-treated soil was differentially abundant in function related to hydrocarbon degradation and functional guilds of symbiotrophs and ectomycorrhizal. This study contributes significantly to our understanding of how the soil fertility and soil microbiome alteration via spinach green manure application as a pre-plant soil treatment might help alleviate continuous cropping obstacles.

Food contamination with pathogenic Escherichia coli can cause severe disease. Here, we report the isolation of a multidrug resistant strain (A23EC) from fresh spinach. A23EC belongs to subclade C2 of ST131, a virulent clone of Extraintestinal Pathogenic E. coli (ExPEC). Most A23EC virulence factors are concentrated in three pathogenicity islands. These include PapGII, a fimbrial tip adhesin linked to increased virulence, and CsgA and CsgB, two adhesins known to facilitate spinach leaf colonization. A23EC also bears TnMB1860, a chromosomally-integrated transposon with the demonstrated potential to facilitate the evolution of carbapenem resistance among non-carbapenemase-producing enterobacterales. This transposon consists of two IS26-bound modular translocatable units (TUs). The first TU carries aac(6)-lb-cr, bla OXA-1, ΔcatB3, aac(3)-lle, and tmrB, and the second one harbors bla CXT-M-15. A23EC also bears a self-transmissible plasmid that can mediate conjugation at 20°C and that has a mosaic IncF [F(31,36):A(4,20):B1] and Col156 origin of replication. Comparing A23EC to 86 additional complete ST131 sequences, A23EC forms a monophyletic cluster with 17 other strains that share the following four genomic traits: (1) virotype E (papGII+); (2) presence of a PAI II536-like pathogenicity island with an additional cnf1 gene; (3) presence of chromosomal TnMB1860; and (4) frequent presence of an F(31,36):A(4,20):B1 plasmid. Sequences belonging to this cluster (which we named C2b sublineage) are highly enriched in septicemia samples and their associated genetic markers align with recent reports of an emerging, virulent sublineage of the C2 subclade, suggesting significant pathogenic potential. This is the first report of a ST131 strain belonging to subclade C2 contaminating green leafy vegetables. The detection of this uropathogenic clone in fresh food is alarming. This work suggests that ST131 continues to evolve, gaining selective advantages and new routes of transmission. This highlights the pressing need for rigorous epidemiological surveillance of ExPEC in vegetables with One Health perspective.

In this study, the effects of organic and chemical fertilizer sources on some essential nutrient elements content, nitrate (NO3−-N) accumulation, and the growth of spinach plant (Spinacia oleracea L.) were investigated. The experiment was carried out in a randomized plot design under greenhouse conditions, with two levels. 1st level; applications with chemical fertilizer. 2nd level; applications without chemical fertilizer. One compost material (kitchen waste compost = KWC), five different doses (0, 0.4, 0.8, 1.2, and 1.6%), and three replications. For chemical fertilization, nitrogen (N) dose of 150 kg ha−1 was applied by using 15-15-15 NPK (N:P2O5:K2O) fertilizer. Overall, KWC applications increased plant growth and nutrient content. However, the most significant increases occurred in the trial subjects where chemical fertilizer and KWC were applied together. The use of KWC together with chemical fertilization increased the leaf width, leaf and stem length, fresh weight, and dry weight, as well as nitrate accumulation, N, potassium (K), and iron (Fe) content of the plant. The highest values of these parameters were obtained at 0.8% dose of KWC + NPK medium. As a result, compost applications were effectively uptake of nutrients and nitrate accumulation remained at acceptable values. [ABSTRACT FROM AUTHOR]

The naturally occurring compounds ecdysterone and turkesterone, which are present in plants, including Rhaponticum carthamoides Willd. (Iljin), Spinacia oleracea L., Chenopodium quinoa Willd., and Ajuga turkestanica (Regel) Briq, are widely recognized due to their possible advantages for both general health and athletic performance. The current review investigates the beneficial biological effects of ecdysterone and turkesterone in nutrition, highlighting their roles not only in enhancing athletic performance but also in the management of various health problems. Plant-based diets, associated with various health benefits and environmental sustainability, often include sources rich in phytoecdysteroids. However, the therapeutic potential of phytoecdysteroid-rich extracts extends beyond sports nutrition, with promising applications in treating chronic fatigue, cardiovascular diseases, and neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

This study focused on the osmotic dehydration (OD) of ready-to-eat spinach leaves combined with the pulsed electric field (PEF) pre-treatment. Untreated and PEF-treated (0.6 kV/cm, 0–200 pulses) spinach leaves were osmotically dehydrated at room temperature for up to 120 min. The application of PEF (0.6 kV/20 pulses) prior to OD (60% glycerol, 25 °C, 60 min) lowered water activity (aw = 0.891) while achieving satisfactory product acceptability (total sensory hedonic scoring of 8). During the storage of the product (at 4, 8, 12, and 20 °C for up to 30 d), a significant reduction in total microbial count evolution was observed (9.7 logCFU/g for the untreated samples vs. 5.1 logCFU/g for the PEF-OD-treated samples after 13 d of storage at 4 °C). The selection of these PEF and OD treatment conditions enabled the extension of the product shelf life by up to 33 d under chilled storage. Osmotically treated spinach could find application in ready-to-eat salad products with an extended shelf life, which is currently not possible due to the high perishability of the specific plant tissue. [ABSTRACT FROM AUTHOR]

Spinach (Spinacia oleracea) is an economically important leafy vegetable grown in the United States and world-wide. The downy mildew pathogen, Peronospora effusa (Pfs), is a major biotic constraint impacting spinach production and quality. The use of resistant cultivars is an economical and environmentally-friendly management option especially in organic production systems. As new races of the pathogen continue to appear, there is a need to continue to select for resistance to the emerging races. The objectives of this study were to evaluate a set of spinach hybrids and F2 breeding populations for resistance to Pfs race 5 to develop a better understanding of the genetics of downy mildew resistance. Also, we screened 39 commercial spinach cultivars for resistance to a recently identified race, Pfs race 19. The genetics of resistance to Pfs 5 was determined by greenhouse inoculations of F1 progeny (individual crosses between near isogenic lines, NIL3 or NIL1 and susceptible genotype, Viroflay) and F2 population progeny (cross between Califlay and susceptible Viroflay). Two hybrids were examined for resistance to Pfs 5. The results indicated that resistance conferred at the RPF1 or the RPF3 loci in a heterozygous (Rr) condition to Pfs 5 was completely dominant. Also, Chi-square analysis of the segregation pattern in the F2 population showed that resistance to Pfs race 5 was conferred by a single dominant gene. A total of 22 out of 39 spinach commercial cultivars were resistant to the newly reported Pfs race 19 and could be used in breeding programs to develop new cultivars with resistance to Pfs 19. [ABSTRACT FROM AUTHOR]

Bacillus thuringiensis-based commercial products as a biopesticide have been used for more than 60 years in agriculture. However, as one of the species in B. cereus group, B. thuringiensis has been considered as an emerging hazard with the potential to cause food toxico-infections. The present study aimed to evaluate the biofilm-forming ability of B. thuringiensis biopesticide strains and their attachment on spinach, compared to foodborne B. cereus strains. Biofilm formations of tested strains were found to be strain-specific and affected by the nutrient conditions more than the incubation time. Nutrient starvation conditions generally reduced the biofilm formation of tested B. thuringiensis and B. cereus strains, particularly B. thuringiensis ABTS-1857 strain was found as the nonbiofilm former in starvation conditions. It is worth mentioning that B. thuringiensis SA-11 strain showed stronger biofilm-forming ability with more air–liquid interface biofilm than the other two B. thuringiensis biopesticide strains, but no such higher attachment of B. thuringiensis SA-11 to spinach was observed. These results indicate that B. thuringiensis SA-11 strain can enter the food processing lines by the attachment on spinach leaves, and it has the potential to form biofilms throughout the processing lines or the production environment when sufficient nutrients are available. However, more biofilm tests of B. thuringiensis biopesticide strains in the vegetable production chain should be performed. The dry formulation of commercial B. thuringiensis biopesticides enhanced their adhesion on spinach leaves, whereas the strength of adhesion was not improved by the formulation. In addition, 1–2 log reductions of spores after the intensive washing of spinach leaves in the lab were detected. However, the log reduction due to the actual washing done by the food processing companies in large-volume washing baths or by consumers at home would be limited and less than this lab simulation.

Spinach (Spinacia oleracea L.) is a leafy green vegetable that belongs to the family Amaranthus, sub-family Chenopodiaceae. It is famous for its low-calorie content and rich nutritional profile of zinc, folic acid, iron, calcium, magnesium, retinol, and ascorbic acid. In contrast, pesticide residues like imidacloprid, cypermethrin, bifenthrin, chlorpyrifos, and deltamethrin and antinutrients like alkaloids, phytates, tannins, and oxalates are also found in spinach, which inhibit nutrient absorption and also exert deleterious effects in humans. The present study was aimed at determining the technofunctional and nutritional characteristics and improving the consumer safety aspects of dehydrated spinach powder (SP). Spinach was processed to improve its safety characteristics using thermal and non-thermal processing techniques, including microwave heat processing, blanching, acid, and alkali soaking. Findings on the nutrient composition of raw and treated forms suggest SP developed from raw spinach as a promising source of ash (2.9%), fibers (8.19%), proteins (19.1%), Na (97.9 mg/100g), Ca (1304 mg/100g), K (234.2 mg/100g), Fe (41.1 mg/100g), and Zn (14.3 mg/100g). Microwave heating anticipated the highest decline of the content of alkaloids, oxalates, tannins, and phytates by 85, 87, 88 and 89%, respectively. Similarly, microwave heating of SP was found to be more promising in reducing the burden of pesticides such as imidacloprid, cypermethrin, bifenthrin, chlorpyrifos, and deltamethrin by 86, 74, 84, 80 and 78%, respectively. Value-added unleavened flatbreads (chapatis) with 5% SP were observed to have the better color, taste, and textural attributes. The study proposes thermal processing i.e., microwave heat processing in particular as a safer approach to reduce the natural antinutrients and extrinsic toxicants of spinach to a level considerably safer for consumption.

Stemphylium leaf spot, caused by Stemphylium vesicarium, and white rust, caused by Albugo occidentalis, can cause significant losses in spinach production. Management of these foliar diseases of spinach has become increasingly challenging with the development of fungicide resistance in some pathogen populations, high planting density and overhead irrigation used for baby leaf spinach production, and the fact that >60% of fresh market spinach production in the United States is certified organic. To identify spinach cultivars with resistance to Stemphylium leaf spot and white rust, a field trial was performed near Crystal City, TX, USA, in 2021 (79 cultivars), 2022 (87 cultivars), and 2023 (63 cultivars). Each year, the plants were inoculated with S. vesicarium and rated for disease severity. Plants were also rated for white rust severity that resulted from natural infection during the 2021 and the 2022 trials. During each trial, 11% to 27% of the cultivars were identified as resistant to Stemphylium leaf spot, and another 29% to 48% had moderately resistant reactions. In contrast, only 5 of 79 cultivars (6%) in the 2021 trial did not develop symptoms of white rust, and all 87 cultivars evaluated in the 2022 trial had symptoms of white rust. Although there was no significant correlation between mean Stemphylium leaf spot ratings and mean white rust ratings during these trials, the cultivars Colusa, Kodiak, PV-1569, and PV-1664 displayed resistant or moderately resistant responses to both diseases in at least two trials. Therefore, processing and fresh market spinach growers have resistant cultivars from which to select to reduce the economic impacts of Stemphylium leaf spot and white rust. [ABSTRACT FROM AUTHOR]

The gastrointestinal tract is the prime organ for digestion while exposing to outer environmental toxins and pathogens. A breach in the epithelial barrier of the gastrointestinal tract will lead to abdominal pain, diarrhea, vomiting, weight loss, growth retardation, ulcers, and extra intestinal manifestation. The current therapeutic approach causes dysbiosis and worsens the symptoms of inflammatory bowel diseases, ultimately leading to colorectal cancer. Herbal medicine is the key to resolving the issue without or least side effects. Current experimental study was executed to evaluate the anti-oxidative and therapeutic potential of both Helianthus annuus seeds and Spinacia oleracea leaves extract against dextran sodium sulfate (DSS) induced acute colitis in Wistar rat and to support the clinical use of herbal medicine with scientific evidence. Results revealed that H. annuus seeds (500 mg/kg) have significantly (P<0.05) higher amount of total phenolic and flavonoid content with higher 2,2-diphenylpicrylhydrazyl (DPPH) reducing power in comparison to S. oleracea leaves (500 mg/kg) extract. The serum total antioxidative capacity was significantly (P<0.05) higher in Helianthuus annuus seeds and Spinacia oleracea leaves as compared to positive control group, while total oxidative stress was significantly lower in both treatment groups as compared to positive control group. Gene expression analysis revealed that JAK/STAT signaling pathways (Cell stress pathways) were significantly (P<0.05) down regulated, and NRF-2 transcriptional pathways (antioxidant pathways) were significantly (P<0.05) upregulated in H. annuus seeds and S. oleracea leaves groups compared to control positive group. The obtained results after analyzing biological samples revealed that Helianthus annuus seeds and Spinacia oleracea leaves possess a significant antioxidant dependent anti-inflammatory potential. Histopathology of gut revealed that positive control group showed irregular epithelial lining with shortening of villi and damaged mucosal surface while treatment group showed recovery with normal epithelial parenchyma. The overall results of this experimental study determined that both herbal interventions elicited an antiinflammatory effect dependent on antioxidative mechanisms in response to experimentally induced acute colitis in Wistar rats. [ABSTRACT FROM AUTHOR]

Ion-exchanging properties of the polymeric matrix of the cell walls isolated from leaves were examined. The glycophyte 55-day-old plants of spinach (Spinacia oleracea L., cv. Matador) grown on a nutrient solution containing 0.5, 150, or 250 mM NaCl and the halophyte seepweed (Suaeda altissima (L.) Pall.) of the same age grown at 0.5, 250, or 750 mM NaCl were compared. The ion-exchange capacity of the cell walls was estimated at different pH and ionic strength of a solution. In the structure of the leaf cell walls, three types of cation-exchange groups were found, namely, two types of carboxylic groups (one of them belongs to galacturonic acid residue) and phenolic OH-groups. The quantities of the groups of each type and their ionization constants were determined. The qualitative composition of the ion-exchange groups in the leaf cell walls was found to be uniform in both plant species regardless of their nutrition. However, the quantity of the carboxylic groups of galacturonic acid depended on the ambient salt concentration in a different manner in the glycophyte and halophyte. This change in the composition of functional groups of cell wall polymers was more pronounced in the halophyte and is apparently one of the responses of these plants to salinization. The sharp increase in the NaCl concentration in the medium leads to a decrease in pH in the extracellular water space due to ion-exchange reactions between sodium ions coming from the external medium and protons of the ionized carboxylic groups of the cell walls. The results are discussed in the aspect of participation of the leaf cell walls in plant responses to salinization. [ABSTRACT FROM AUTHOR]

PSY (phytoene synthase, PSY) is the first rate‑limiting enzyme in the plant carotenoid synthesis pathway and plays an important role in plant growth and development. In order to understand the function of PSY gene family in spinach, the number, structure, promoter elements, amino acid characteristics and gene evolution of PSY gene family members in spinach were identified by bioinformatics method, and the expression pattern of PSY genes in spinach tissue and in response to the changes in the ratio of red to blue light was analyzed by real‑time fluorescence quantitative PCR (RT‑qPCR) . Meanwhile, the expressions of R1B3 (red∶blue light = 1∶3) and R3B1 (red light∶blue light = 3∶1) and the correlation between SoPSYs gene expression and total carotenoid content were analyzed. The results showed that there were 4 PSY genes in spinach, containing SQS_PSY conserved domain, and the SoPSY protein was a hydrophilic protein. PSY1 and PSY2 of spinach were closely related to beet in Amaranthaceae, and PSY3 and PSY4 were closely related to PSY3 in tomato. There were various light‑responsive and phytohormone‑related elements in the promoter sequence of spinach PSY genes. SoPSY genes had tissue expression specificity, SoPSY1, SoPSY2, and SoPSY3 were only expressed in the leaves, and SoPSY4 was mainly expressed in the roots. Spinach carotene content decreased after treatment with R1B3 and R3B1. Among spinach genotypes, the expression patterns of each SoPSY gene in response to the ratio of red to blue light were different. The expression of SoPSY1 was not significantly changed in cultivated spinach, the expression patterns of SoPSY2 were reversed in both spinach genotypes, and the relative expression patterns of SoPSY3 were consistent in the wild and cultivated spinach, and the relative expressions of these three genes was closely related to the change of total carotenoid content. This study lays the foundation for an in‑depth understanding of the biological function of the PSY genes in spinach and their regulatory mechanism in response to changes in the ratio of red to blue light. [ABSTRACT FROM AUTHOR]

In recent years, a new root rot disease in barley, which is caused by an Aphanomyces species, was found in field surveys in Southern Sweden and Denmark. Its symptoms occurred at the early tillering stage, around the BBCH 21 growth stage, and included the yellowing of leaves, brown coleoptiles, and the discolouration of roots. Prolonged soil wetness after rainfall favoured disease development, which sometimes advanced the yellowing patches to entire fields, resulting in lower yields. Oospores were found in the fine roots of diseased plants, and Aphanomyces isolates were obtained from these roots, as well as from the roots of barley plants grown in the greenhouse in soil samples from infected fields. Based on morphological analysis, we found that the new isolates were similar to those already obtained from barley and spinach roots in the 1990s in the same growing area. The morphological and molecular analyses performed in this study clearly separated and distinguished these barley isolates from other known Aphanomyces, and hereby Aphanomyces macrosporus sp. nov. is proposed as a new plant pathogenic species. It has larger oogonia and oospores than A. euteiches, A. cochlioides, and A. cladogamus, with one up to eight diclinous antheridia per oogonium. The phylogenetic analysis of the ITS rDNA region sequences grouped these new Aphanomyces isolates in a monophyletic clade, which was clearly distinguished from other plant pathogenic Aphanomyces species. The further pathogenicity of A. macrosporus on other plants is currently under investigation, but it is clear that it can at least infect barley, spinach, and sugar beet, indicating a wide host range for this species. The widespread presence and presumably broad host range of this new pathogenic Aphanomyces species must be considered in crop rotations. [ABSTRACT FROM AUTHOR]

Abstract Background Women with polycystic ovary syndrome (PCOS) have higher intestinal mucosal permeability, leading to the lipopolysaccharide (LPS) leakage and endotoxemia. This, in turn, leads to oxidative stress (OS) and neuro-inflammation caused by the gut-brain axis, affecting the neurotrophic factors levels such as brain-derived neurotrophic factor (BDNF) and S100 calcium-binding protein B (S100 B) levels. In this study, it was hypothesized that the thylakoid membranes of spinach supplementation along with a hypocaloric diet may have improved the LPS levels, neurotrophic factors, and OS in PCOS patients. Methods In this double-blind, randomized, placebo-controlled, and clinical trial, 48 women with obesity and diagnosed with PCOS based on Rotterdam criteria were randomly assigned to thylakoid (N = 21) and placebo groups (N = 23). A personalized hypocaloric diet with 500 calories less than the total energy expenditure was prescribed to all patients. The participants were daily supplemented with either a 5 g/day thylakoid-rich spinach extract or a placebo (5 g cornstarch) for 12 weeks along with a prescribed low-calorie diet. Anthropometric measurements and biochemical parameters were assessed at baseline and after the 12-week intervention. Results A statistically significant decrease in the LPS levels (P 0.05). Conclusions In sum, the thylakoid membranes of spinach supplemented with a hypocaloric diet reduced the LPS levels, increased the BDNF levels, and improved the glycemic profile and sex-hormone levels; however, they had no effects on the OS markers levels after 12 weeks of intervention.

Diclofenac, often detected in environmental samples, poses a potential hazard to the aquatic environment. The present study aimed to understand the effect of this drug on photosynthetic apparatus, which is a little-known aspect of its phytotoxicity. Chloroplasts and thylakoids isolated from spinach (Spinacia oleracea) were used for this study and treated with various concentrations of diclofenac (from 125 to 4000 μM). The parameters of chlorophyll a fluorescence (the OJIP test) as measurements for both the intact chloroplasts and the thylakoid membranes revealed that isolated thylakoids showed greater sensitivity to the drug than chloroplasts. The relatively high concentration of diclofenac that is required to inhibit chloroplast and thylakoid functions suggests a narcotic effect of that drug on photosynthetic membranes, rather than a specific interaction with a particular element of the electron transport chain. Using confocal microscopy, we confirmed the degradation of the chloroplast structure after DCF treatment, which has not been previously reported in the literature. In conclusion, it can be assumed that diclofenac’s action originated from a non-specific interaction with photosynthetic membranes, leading to the disruption in the function of the electron transport chain. This, in turn, decreases the efficiency of photosynthesis, transforming part of the PSII reaction centers into heat sinks and enhancing non-photochemical energy dissipation.

Stemphylium leaf spot, caused by Stemphylium vesicarium, and white rust, caused by Albugo occidentalis, can cause significant losses in spinach production. Management of these foliar diseases of spinach has become increasingly challenging with the development of fungicide resistance in some pathogen populations, high planting density and overhead irrigation used for baby leaf spinach production, and the fact that >60% of fresh market spinach production in the United States is certified organic. To identify spinach cultivars with resistance to Stemphylium leaf spot and white rust, a field trial was performed near Crystal City, TX, USA, in 2021 (79 cultivars), 2022 (87 cultivars), and 2023 (63 cultivars). Each year, the plants were inoculated with S. vesicarium and rated for disease severity. Plants were also rated for white rust severity that resulted from natural infection during the 2021 and the 2022 trials. During each trial, 11% to 27% of the cultivars were identified as resistant to Stemphylium leaf spot, and another 29% to 48% had moderately resistant reactions. In contrast, only 5 of 79 cultivars (6%) in the 2021 trial did not develop symptoms of white rust, and all 87 cultivars evaluated in the 2022 trial had symptoms of white rust. Although there was no significant correlation between mean Stemphylium leaf spot ratings and mean white rust ratings during these trials, the cultivars Colusa, Kodiak, PV-1569, and PV-1664 displayed resistant or moderately resistant responses to both diseases in at least two trials. Therefore, processing and fresh market spinach growers have resistant cultivars from which to select to reduce the economic impacts of Stemphylium leaf spot and white rust.

Background: Women with polycystic ovary syndrome (PCOS) have higher intestinal mucosal permeability, leading to the lipopolysaccharide (LPS) leakage and endotoxemia. This, in turn, leads to oxidative stress (OS) and neuro-inflammation caused by the gut-brain axis, affecting the neurotrophic factors levels such as brain-derived neurotrophic factor (BDNF) and S100 calcium-binding protein B (S100 B) levels. In this study, it was hypothesized that the thylakoid membranes of spinach supplementation along with a hypocaloric diet may have improved the LPS levels, neurotrophic factors, and OS in PCOS patients. Methods: In this double-blind, randomized, placebo-controlled, and clinical trial, 48 women with obesity and diagnosed with PCOS based on Rotterdam criteria were randomly assigned to thylakoid (N = 21) and placebo groups (N = 23). A personalized hypocaloric diet with 500 calories less than the total energy expenditure was prescribed to all patients. The participants were daily supplemented with either a 5 g/day thylakoid-rich spinach extract or a placebo (5 g cornstarch) for 12 weeks along with a prescribed low-calorie diet. Anthropometric measurements and biochemical parameters were assessed at baseline and after the 12-week intervention. Results: A statistically significant decrease in the LPS levels (P < 0.001) and an increase in the BDNF levels (P < 0.001) were recorded for the participants receiving the oral thylakoid supplements and a low-calorie diet. Furthermore, significant decreases were observed in fasting blood glucose, insulin, homeostatic model of assessment for insulin resistance, free testosterone index, and follicle-stimulating hormone / luteinizing hormone ratio in both groups (P < 0.05). No significant differences were detected between the two groups regarding the changes in malondialdehyde, catalase, total antioxidant capacity, and S100B levels (P > 0.05). Conclusions: In sum, the thylakoid membranes of spinach supplemented with a hypocaloric diet reduced the LPS levels, increased the BDNF levels, and improved the glycemic profile and sex-hormone levels; however, they had no effects on the OS markers levels after 12 weeks of intervention. [ABSTRACT FROM AUTHOR]

Spinach (Spinacia oleracea) is a winter-season green, leafy vegetable grown all over the world, belonging to the family Amaranthus, sub-family Chenopodiaceae. Spinach is a low-caloric food and an enormous source of micronutrients, e.g., calcium, folates, zinc, retinol, iron, ascorbic acid and magnesium. Contrarily, it also contains a variety of anti-nutritional factors, e.g., alkaloids, phytates, saponins, oxalates, tannins and many other natural toxicants which may hinder nutrient-absorption. This study was aimed at investigating the effect of fermentation on improving the nutrient-delivering potential of spinach and mitigating its burden of antinutrients and toxicants at three growth stages: the 1st growth stage as baby leaves, the 2nd growth stage at the coarse stage, and the 3rd growth stage at maturation. The results revealed the significant (p < 0.05) effect of fermentation on increasing the protein and fiber content of spinach powder from 2.53 to 3.53% and 19.33 to 22.03%, respectively, and on reducing total carbohydrate content from 52.92 to 40.52%; the effect was consistent in all three growth stages. A significant decline in alkaloids (6.45 to 2.20 mg/100 g), oxalates (0.07 mg/100 g to 0.02 mg/100 g), phytates (1.97 to 0.43 mg/100 g) and glucosinolates (201 to 10.50 µmol/g) was observed as a result of fermentation using Lactiplantibacillus plantarum. Fermentation had no impact on total phenolic content and the antioxidant potential of spinach, as evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays. This study proposes fermentation as a safer bioprocess for improving the nutrient-delivering potential of spinach, and suggests processed powders made from spinach as a cost-effective complement to existing plant proteins. [ABSTRACT FROM AUTHOR]

In sub-Saharan Africa, chronic malnutrition is often associated with intestinal inflammation and oxidative stress. African green leafy vegetables (GLVs), commonly consumed by these populations and rich in bioactive compounds, may improve the antioxidant status. The aim of this study was to measure the antioxidant capacity using complementary assays (DPPH, FRAP, ABTS, ORAC and NO scavenging) in polar and non-polar leaf extracts of four African GLVs, cassava (Manihot esculenta), roselle (Hibiscus sabdariffa), jute mallow (Corchorus olitorius), and amaranth (Amaranthus spp.), with spinach (Spinacia oleracea) chosen as a reference. Their antioxidant capacity was correlated with their total polyphenol (TPC), flavonoid (TFC), condensed tannin, lutein, and β-carotene contents. Identification of phenolic compounds by UHPLC-DAD-MS/MS revealed the presence of three main classes of compound: flavonols, flavones, and hydroxycinnamic acids. Cassava and roselle leaves presented significantly higher TPC and TFC than amaranth, jute mallow, and spinach. They also exhibited the highest antioxidant capacity, even higher than that of spinach, which is known for its important antioxidant effect. The antioxidant capacity was 2 to 18 times higher in polar than non-polar extracts, and was more strongly correlated with TPC and TFC (R > 0.8) than with β-carotene and lutein contents. These findings provide new data especially for cassava and roselle leaves, for which studies are scarce, suggesting an appreciable antioxidant capacity compared with other leafy vegetables. [ABSTRACT FROM AUTHOR]

This study focused on the osmotic dehydration (OD) of ready-to-eat spinach leaves combined with the pulsed electric field (PEF) pre-treatment. Untreated and PEF-treated (0.6 kV/cm, 0–200 pulses) spinach leaves were osmotically dehydrated at room temperature for up to 120 min. The application of PEF (0.6 kV/20 pulses) prior to OD (60% glycerol, 25 °C, 60 min) lowered water activity (aw = 0.891) while achieving satisfactory product acceptability (total sensory hedonic scoring of 8). During the storage of the product (at 4, 8, 12, and 20 °C for up to 30 d), a significant reduction in total microbial count evolution was observed (9.7 logCFU/g for the untreated samples vs. 5.1 logCFU/g for the PEF-OD-treated samples after 13 d of storage at 4 °C). The selection of these PEF and OD treatment conditions enabled the extension of the product shelf life by up to 33 d under chilled storage. Osmotically treated spinach could find application in ready-to-eat salad products with an extended shelf life, which is currently not possible due to the high perishability of the specific plant tissue.

This investigation identifies a plant growth-promoting rhizobacteria which can improve the heat tolerance of spinach (Spinacia oleracea L.). Bacillus licheniformis strain (named B. licheniformis BE-L60) was isolated from the heat-stressed spinach rhizosphere soil.It secretesindole-3-acetic acid, dissolve phosphorus, and produces amylases and proteases. Compared toun-inocculated spinach seedlings, those inoculated with BE-L60 had higher contents of soluble protein, proline, and sugar and enhanced the functions of antioxidant enzymes superoxide dismutase, peroxidase, and catalase. The results indicated that BE-L60 maintained the osmoprotectant levels to improve ion homeostasis and activates the antioxidant defense system. It was also identified via transcriptome analysis that heat stress could be alleviatedthe expression of heat shock protein genes. Overall, BE-L60 enhanced spinach seedlings' heat tolerance by modulating plants' physiological and biochemical processes. [ABSTRACT FROM AUTHOR]

The present study was conducted for a period of 60 days to determine the growth performance of Common carp (Cyprinus carpio var. communis) fingerlings at different stocking densities and Spinach (Spinacia oleracea) plant, grown in deep water aquaponic system. The experiment, was conducted with five treatments each with three replicates. A homogenous stock of fingerlings was randomly distributed in five treatment groups with stocking density of 5, 10, 15, 20 and 25 fish in T1, T2, T3, T4 and T5, respectively with addition of 10 plants in each tank. The fish was fed at 3% of their body weight. The result of the study shows that fish in treatment-T3 with stocking density 15 had shown maximum and significantly higher growth then other treatments. SGR (2.185±0.010) and GCE (0.873±0.008) were also significantly higher in T3, whereas, the FCR was lowest (1.145±0.010) in T3. The net length gain and root length gain were significantly higher in spinach plant in T5 compared to other treatments. Increment in number of leaves was also significantly higher in T5 compared to other treatments. Variation in water quality between all treatments in all the parameters was non-significant throughout the experimental period. The results showed the highest plant growth observed in T5, which had a stocking density of 25 fishes. Through this experiment, we can conclude that plant growth in the present aquaponic system was found to increase with increase in stocking density of fish. But the fish growth was observed maximum in T3 with stocking density of 15 fishes per tank. [ABSTRACT FROM AUTHOR]

The Food Safety Modernization Act (FSMA) includes a time-to-harvest interval following the application of noncompliant water to preharvest produce to allow for microbial die-off. However, additional scientific evidence is needed to support this rule. This study aimed to determine the impact of weather on the die-off rate of Escherichia coli and Salmonella on spinach and lettuce under field conditions. Standardized, replicated field trials were conducted in California, New York, and Spain over 2 years. Baby spinach and lettuce were grown and inoculated with an ∼104-CFU/ml cocktail of E. coli and attenuated Salmonella Leaf samples were collected at 7 time points (0 to 96 h) following inoculation; E. coli and Salmonella were enumerated. The associations of die-off with study design factors (location, produce type, and bacteria) and weather were assessed using log-linear and biphasic segmented log-linear regression. A segmented log-linear model best fit die-off on inoculated leaves in most cases, with a greater variation in the segment 1 die-off rate across trials (-0.46 [95% confidence interval {95% CI}, -0.52, -0.41] to -6.99 [95% CI, -7.38, -6.59] log10 die-off/day) than in the segment 2 die-off rate (0.28 [95% CI, -0.20, 0.77] to -1.00 [95% CI, -1.16, -0.85] log10 die-off/day). A lower relative humidity was associated with a faster segment 1 die-off and an earlier breakpoint (the time when segment 1 die-off rate switches to the segment 2 rate). Relative humidity was also found to be associated with whether die-off would comply with FSMA's specified die-off rate of -0.5 log10 die-off/day.IMPORTANCE The log-linear die-off rate proposed by FSMA is not always appropriate, as the die-off rates of foodborne bacterial pathogens and specified agricultural water quality indicator organisms appear to commonly follow a biphasic pattern with an initial rapid decline followed by a period of tailing. While we observed substantial variation in the net culturable population levels of Salmonella and E. coli at each time point, die-off rate and FSMA compliance (i.e., at least a 2 log10 die-off over 4 days) appear to be impacted by produce type, bacteria, and weather; die-off on lettuce tended to be faster than that on spinach, die-off of E. coli tended to be faster than that of attenuated Salmonella, and die-off tended to become faster as relative humidity decreased. Thus, the use of a single die-off rate for estimating time-to-harvest intervals across different weather conditions, produce types, and bacteria should be revised.

BACKGROUND:Detection and diagnosis of emerging arthropod outbreaks in horticultural glasshouse crops, such as bok choy and spinach, is both important and challenging. A major challenge is to accurately detect and diagnose arthropod outbreaks in growing crops (changes in canopy size, structure, and composition), and when crops are grown under three fertilization regimes. Day-time remote sensing inside glasshouses is highly sensitive to inconsistent lighting, spectral scattering, and shadows casted by glasshouse structures. To avoid these issues, a unique feature of this study was that hyperspectral remote sensing data were acquired after sunset with an active light source. As part of this study, we describe a comprehensive approach to performance assessment of classification algorithms based on hyperspectral remote sensing data. RESULTS:Based on average hyperspectral remote sensing profiles from individual crop plants, none of the 31 individual spectral bands showed consistent significant response to leafminer infestation and non-significant response to fertilizer regime. Multi-band classification algorithms were subjected to a comprehensive performance assessment to quantify risks of model over-fitting and low repeatability of classification algorithms. The performance assessment of classification algorithms addresses the important 'bias-variance trade-off'. Truly independent validation (training and validation data sets being separated over time) revealed that leafminer infestation could be detected with >99% accuracy in both bok choy and spinach. CONCLUSION:We conclude that detailed hyperspectral profiles (not single spectral bands) can accurately detect and diagnose leafminer infestation over time and across fertilizer regimes. Hyperspectral remote sensing data acquisition at night with an active light source has the potential to enable arthropod infestations in glasshouse-grown crops, such as, bok choy and spinach. In addition, we conclude that effective use and deployment of hyperspectral remote sensing requires thorough performance assessments of classification algorithms, and we propose an analytical performance method to address this important matter. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Thylakoid membranes in chloroplasts contain photosynthetic protein complexes that convert light energy into chemical energy. Photosynthetic protein complexes are considered to undergo structural reorganization to maintain the efficiency of photochemical reactions. A detailed description of the mobility of photosynthetic complexes in real time is necessary to understand how macromolecular organization of the membrane is altered by environmental fluctuations. Here, we used high-speed atomic force microscopy to visualize and characterize the in situ mobility of individual protein complexes in grana thylakoid membranes isolated from Spinacia oleracea. Our observations reveal that these membranes can harbor complexes with at least two distinctive classes of mobility. A large fraction of grana membranes contained proteins with quasistatic mobility exhibiting molecular displacements smaller than 10 nm2. In the remaining fraction, the protein mobility is variable with molecular displacements of up to 100 nm2. This visualization at high spatiotemporal resolution enabled us to estimate an average diffusion coefficient of ∼1 nm2 s-1. Interestingly, both confined and Brownian diffusion models could describe the protein mobility of the second group of membranes. We also provide the first direct evidence, to our knowledge, of rotational diffusion of photosynthetic complexes. The rotational diffusion of photosynthetic complexes could be an adaptive response to the high protein density in the membrane to guarantee the efficiency of electron transfer reactions. This characterization of the mobility of individual photosynthetic complexes in grana membranes establishes a foundation that could be adapted to study the dynamics of the complexes inside intact and photosynthetically functional thylakoid membranes to be able to understand its structural responses to diverse environmental fluctuations.

Downy mildew of spinach is caused by the obligate oomycete pathogen, Peronospora effusa. The disease causes significant economic losses, especially in the organic sector of the industry where the use of synthetic fungicides is not permitted for disease control. New pathotypes of this pathogen are increasingly reported which are capable of breaking resistance. In this study, we took advantage of new spinach genome resources to conduct RNA-seq analyses of transcriptomic changes in leaf tissue of resistant and susceptible spinach cultivars Solomon and Viroflay, respectively, at an early stage of pathogen establishment (48 hours post inoculation, hpi) to a late stage of symptom expression and pathogen sporulation (168 hpi). Fold change differences in gene expression were recorded between the two cultivars to identify candidate genes for resistance. In Solomon, the hypersensitive inducible genes such as pathogenesis-related gene PR-1, glutathione-S-transferase, phospholipid hydroperoxide glutathione peroxidase and peroxidase were significantly up-regulated uniquely at 48 hpi and genes involved in zinc finger CCCH protein, glycosyltransferase, 1-aminocyclopropane-1-carboxylate oxidase homologs, receptor-like protein kinases were expressed at 48 hpi through 168 hpi. The types of genes significantly up-regulated in Solomon in response to the pathogen suggests that salicylic acid and ethylene signaling pathways mediate resistance. Furthermore, many genes involved in the flavonoid and phenylpropanoid pathways were highly expressed in Viroflay compared to Solomon at 168 hpi. As anticipated, an abundance of significantly down-regulated genes was apparent at 168 hpi, reflecting symptom development and sporulation in cultivar Viroflay, but not at 48 hpi. In the pathogen, genes encoding RxLR-type effectors were expressed during early colonization of cultivar Viroflay while crinkler-type effector genes were expressed at the late stage of the colonization. Our results provide insights on gene expression in resistant and susceptible spinach-P. effusa interactions, which can guide future studies to assess candidate genes necessary for downy mildew resistance in spinach.

Several 'super-complexes' of individual hetero-oligomeric membrane protein complexes, whose function is to facilitate intra-membrane electron and proton transfer and harvesting of light energy, have been previously characterized in the mitochondrial cristae and chloroplast thylakoid membranes. We report the presence of an intra-membrane super-complex dominated by the ATP-synthase, photosystem I (PSI) reaction-center complex and the ferredoxin-NADP+ Reductase (FNR) in the thylakoid membrane. The presence of the super-complex has been documented by mass spectrometry, clear-native PAGE and Western Blot analyses. This is the first documented presence of ATP synthase in a super-complex with the PSI reaction-center located in the non-appressed stromal domain of the thylakoid membrane.

Introduction: Various advances have been made in pharmacology and synthetic organic chemistry, the dependency on natural products, particularly on herbs, remains relatively unchanged. Among various herbal products that are being used in dentistry, efficacy of mouthwash prepared using Momordica charantia extract and Spinacia oleracea extract on prevention of caries in children has not been researched yet. Hence, in this study the antibacterial efficacy of chlorhexidine mouthwash was evaluated and compared with Momordica charantia, Spinacia oleracea mouthwash against Streptococcus mutans and Lactobacillus acidophilus, Porphyromonas gingivalis. To evaluate and compare the antimicrobial efficacy of chlorhexidine mouthwash and Momordica charantia, Spinacia oleracea mouthwash against Streptococcus mutans, Lactobacillus acidophilus, and Porphyromonas gingivalis. Materials and Methods: Ethanolic extract of Momordica charantia and Spinacia oleracea was prepared. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these extracts were then determined against Streptococcus mutans, Lactobacillus acidophilus, and Porphyromonas gingivalis using resazurin method and agar plate streaking method. Herbal mouthwashes were then prepared from the extracts using MIC and MBC values and its cytotoxicity was determined using MTT assay. Antibacterial susceptibility was then determined using agar well diffusion method and time-kill assay. Results: There is no statistically significant difference in the effectiveness of chlorhexidine mouthwash and Momordica charantia, Spinacia oleracea mouthwash against Streptococcus mutans, Lactobacillus acidophilus, and Porphyromonas gingivalis. Conclusion: Momordica charantia extract mouthwash and Spinacia oleracea extract mouthwash can be used as an herbal alternative as it has equal antibacterial efficacy against Streptococcus mutans, Lactobacillus acidophilus, Porphyromonas gingivalis as compared to 0.2% chlorhexidine mouthwash.

ustainable agriculture is a vital aspect of long-term development, as it contributes to food security and the conservation of natural ecosystem biodiversity through the efficient use of agricultural inputs. It accomplishes this through enhancing agro-technology such as the foliar application of agrochemicals, which should be implied to ensure agricultural sustainability. The purpose of this study was to determine the effects of foliar fertilizer application on plant growth and nutrition over soil application. A pot experiment was conducted to study the growth and yield response of spinach (Spinacia oleracea, L.) to foliar application of Urea-TSP-MoP. There were five treatments comprising of control, recommended NPK fertilizer dose applied in soil, and 0.002% level foliar spray NPK ratios 19:19:19, 10:20:30, and 30:10:10 respectively. A randomized complete block design (RCBD) with three replications was used to arrange the treatments. Results indicated that plant height (cm), number of leaves (plant-1), leaf blade length (cm), leaf blade width(cm), leaf petiole length(cm) was higher in foliar treatments. However, fresh weight of leaf(g), the total biomass of plant(t/ha), dry weight of plant(g), fresh root biomass (g), and dry root biomass (g), were obtained significantly greater in recommended NPK fertilizer comparison to control and foliar treatments. Application of recommended NPK fertilizer dose in soil application produced the highest fresh leaf mass and total yield of spinach 26.03 t/ha followed by foliar treatments of 23.20 t/ha, 22.20 t/ha, 23.40 t/ha, compared to control where obtained yield about 16.77 t/ha. There were no significant differences between foliar application for yield parameters of spinach. It is concluded that foliar feeding produces nearly the same yield as conventional feeding and is more sustainable.

Spinacia oleracea Linn., commonly known as spinach, has been traditionally used in ethnomedical therapy for various purposes, including the treatment of obesity, lung inflammation, lumbago, flatulence, and urinary calculi. In this study, we investigated the protective effects of petroleum ether (SOPE) and ethanolic (SOEE) extracts of Spinacia oleracea against indomethacin-induced enterocolitis in a rat model. Additionally, acute oral toxicity was evaluated using the Up-and-Down Procedure (Test No. 425: Acute Oral Toxicity). Results revealed the safety of both SOPE and SOEE at a dose of 2000 mg/kg, with normal observations in behavioral, body weight, organ weight, biochemical, and hematological parameters, except for slight alterations in respiration and salivation with SOPE and SOEE respectively. In the disease model, SOPE at 400 mg/kg and SOEE at 200 and 400 mg/kg exhibited significant protective effects against indomethacin-induced enterocolitis. These effects were evident through improvements in macroscopic, biochemical, hematological, and histological data. Overall, the findings suggest that SOEE exhibits more pronounced protective effects against indomethacin-induced enterocolitis compared to SOPE, possibly due to the presence of polyphenolic phytoconstituents in SOEE. [ABSTRACT FROM AUTHOR]

More research is needed to understand the benefits of environmentally safe and human-friendly herbal-based sunscreen agents against ultraviolet (UV) radiation. Because of the toxicity of synthetic chemicals in photoprotective agents, researchers were increasingly focusing on herbal photoprotective formulations. The photoprotective agent's skin retention can be considerably improved by forming solid lipid nanoparticles (SLN). The study's objective is to evaluate the photoprotective potential of sunscreen cream containing spinach (Spinacia oleracea)-loaded SLN. A solvent emulsification technique was used to develop the spinach-loaded SLN. The various characterization techniques of the developed SLN were performed. Out of all the formulations, the optimized one was fitted into cream and estimated for its photoprotective action. The images obtained from scanning electron microscopy (SEM) revealed the morphological characteristics of the prepared SLN. The sunscreen cream's viscosity, spreadability, extrudability, and release rate were within acceptable limits. The formulation's in vitro and in vivo sun protection factor (SPF) was reported to be 15.9 and 14.75, respectively. The results indicated that the prepared formulation possesses good photoprotective action. The accelerated stability tests were carried out with no noticeable changes in the parameters. Our work demonstrated the possibility of using spinach-loaded SLN as a photoprotective agent in cosmetic formulations. [ABSTRACT FROM AUTHOR]

Soil health is one of the most important factors that influence plant productivity. Incorporation of soil into plant residues that are high in organic matter has been reported to improve soil's physical and chemical properties which enhance plant growth and development. Therefore, the objective of this study was to investigate the effect of soils amended with different spent oyster mushroom substrates on seedling emergence and growth of spinach (Spinacia oleracea). The respective soil samples were amended with different Spent Mushroom Substrates (SMS) at ratio 60:40 (soil/substrate). Treatments were: T1= U. panicoides + soil, T2= Z. mays + soil, T3= D. stramonium + soil, T4= Substrate mix [60% soil: U. panicoides (13.33%), Z. mays (13.33%) and D. stramonium (13.33%)] and T5= un-amended soil (100%). The respective treatments were filled into 25cm diameter pots and arranged in a Complete Randomized Design (CRD) in a temperature-controlled glasshouse. In each respective pot, three S. oleracea seeds were planted at a depth of 2cm and watered 3 times a week. S. oleracea growth response was determined by assessing the following variables: emergence rate, plant height, number of leaves/plant and chlorophyll content over a period of 12 weeks. Total dry biomass was assessed at harvest by oven drying the plants at 60°C for 72 hrs. On the first assessment, seedlings raised in Z. mays SMS had significantly higher emergence percentage than seedlings raised in D. stramonium, Substrate mix, U. panicoides SMS (p<0.05). Seedlings raised in Z. mays SMS attained 100% emergence 7 days after planting (DAP), and un-amended soils had 91.75% 9 DAP. Seedlings raised in Z. mays and D. stramonium SMS had significantly higher plant height than seedlings raised in U. panicoides SMS and un-amended soils (p<0.05). Seedlings raised in Z. mays SMS attained 26.27cm height compared to U. panicoides SMS and un-amended soils which attained 12.67cm and 14cm height, respectively. Findings of this study revealed that Z. mays and D. stramonium SMS amended soils have inherent properties that positively influenced the seedling emergence, establishment, and growth of S. oleracea. This would, therefore, have influence on the leaves which are the main agronomic yield of the crop. [ABSTRACT FROM AUTHOR]

Although the importance of nonphotochemical quenching (NPQ) on photosynthetic biomass production and crop yields is well established, the in vivo operation of the individual mechanisms contributing to overall NPQ is still a matter of controversy. In order to investigate the timescale and activation dynamics of specific quenching mechanisms, we have developed a technique called snapshot transient absorption (TA) spectroscopy, which can monitor molecular species involved in the quenching response with a time resolution of 30 s. Using intact thylakoid membrane samples, we show how conventional TA kinetic and spectral analyses enable the determination of the appropriate wavelength and time delay for snapshot TA experiments. As an example, we show how the chlorophyll-carotenoid charge transfer and excitation energy transfer mechanisms can be monitored based on signals corresponding to the carotenoid (Car) radical cation and Car S1 excited state absorption, respectively. The use of snapshot TA spectroscopy together with the previously reported fluorescence lifetime snapshot technique (Sylak-Glassman et al. in Photosynth Res 127:69-76, 2016) provides valuable information such as the concurrent appearance of specific quenching species and overall quenching of excited Chl. Furthermore, we show that the snapshot TA technique can be successfully applied to completely intact photosynthetic organisms such as live cells of Nannochloropsis. This demonstrates that the snapshot TA technique is a valuable method for tracking the dynamics of intact samples that evolve over time, such as the photosynthetic system in response to high-light exposure.

A comparative investigation was conducted to evaluate transcriptional changes in guard cells (GCs) of closely related halophytic (Chenopodium quinoa) and glycophytic (Spinacia oleracea) species. Plants were exposed to 3 weeks of 250 mM sodium chloride treatment, and GC-enriched epidermal fragments were mechanically prepared. In both species, salt-responsive genes were mainly related to categories of protein metabolism, secondary metabolites, signal transduction and transport systems. Genes related to abscisic acid (ABA) signaling and ABA biosynthesis were strongly induced in quinoa but not in spinach GCs. Also, expression of the genes encoding transporters of amino acids, proline, sugars, sucrose and potassium increased in quinoa GCs under salinity stress. Analysis of cell-wall-related genes suggests that genes involved in lignin synthesis (e.g. lignin biosynthesis LACCASE 4) were highly upregulated by salt in spinach GCs. In contrast, transcripts related to cell wall plasticity Pectin methylesterase3 (PME3) were highly induced in quinoa. Faster stomatal response to light and dark measured by observing kinetics of changes in stomatal conductance in quinoa might be associated with higher plasticity of the cell wall regulated by PME3 Furthermore, genes involved in the inhibition of stomatal development and differentiation were highly expressed by salt in quinoa, but not in spinach. These changes correlated with reduced stomatal density and index in quinoa, thus improving its water use efficiency. The fine modulation of transporters, cell wall modification and controlling stomatal development in GCs of quinoa may have resulted in high K+/Na+ ratio, lower stomatal conductance and higher stomatal speed for better adaptation to salinity stress in quinoa. [ABSTRACT FROM AUTHOR]