Transcriptome analysis of Snow Mountain Garlic for unraveling the organosulfur metabolic pathway.

Snow Mountain Garlic grows in the high altitudes of the Himalayas under low temperature conditions. It contains various bioactive compounds whose metabolic pathways have not been worked out at genomic level. The present work is the first report on the transcriptome sequencing of this plant. >43 million paired-end reads (301 × 2) were generated using Illumina Miseq sequencing technology. Assembling of the sequencing data resulted in 326,785 transcripts. Differentially expressed genes between the clove and leaf tissues were identified and characterized. Besides, greater emphasis was laid on the genes, which were highly expressed in clove since the latter is assumed to contain high content of the bioactive compounds. Further analysis led to the identification of the genes plausibly involved in the organosulfur metabolism. We also identified several simple sequence repeats and single nucleotide polymorphism. These constitute valuable genetic resource for research and further genetic improvement of the plant.

Spirostanol Saponins from Flowers of Allium Porrum and Related Compounds Indicating Cytotoxic Activity and Affecting Nitric Oxide Production Inhibitory Effect in Peritoneal Macrophages.

Saponins, a diverse group of natural compounds, offer an interesting pool of derivatives with biomedical application. In this study, three structurally related spirostanol saponins were isolated and identified from the leek flowers of Allium porrum L. (garden leek). Two of them were identical with the already known leek plant constituents: aginoside (1) and 6-deoxyaginoside (2). The third one was identified as new component of A. porrum; however, it was found identical with yayoisaponin A (3) obtained earlier from a mutant of elephant garlic Allium ampeloprasun L. It is a derivative of the aginoside (1) with additional glucose in its glycosidic chain, identified by MS and NMR analysis as (2α, 3ß, 6ß, 25R)-2,6-dihydroxyspirostan-3-yl ß-D-glucopyranosyl-(1 → 3)-ß-D-glucopranosyl-(1 → 2)-[ß-D-xylopyranosyl-(1 → 3)]-ß-D-glucopyranosyl]-(1 → 4)-ß-D-galactopyranoside, previously reported also under the name alliporin. The leek native saponins were tested together with other known and structurally related saponins (tomatonin and digitonin) and with their related aglycones (agigenin and diosgenin) for in vitro cytotoxicity and for effects on NO production in mouse peritoneal cells. The highest inhibitory effects were exhibited by 6-deoxyaginoside. The obtained toxicity data, however, closely correlated with the suppression of NO production. Therefore, an unambiguous linking of obtained bioactivities of saponins with their expected immunobiological properties remained uncertain.

Allium porrum and Bauhinia Variegata Mitigate Acute Liver Failure and Nephrotoxicity Induced by Thioacetamide in Male Rats.

The present work has been designed to investigate the hepatoprotective and renoprotective efficiency of alcoholic extract of Allium porrum and Bauhinia variegata leaves in thioacetamide-induced toxicity in adult Wistar rats. Allium porrum leaf extract, Bauhinia variegata leaf extract and their combinations were orally administered for 14 days then TAA (300 mg/kg) i.p. was injected once and the rats were sacrificed 2 days later. Plasma AST, ALT, GGT, total bilirubin, creatinine, urea, uric acid, triglyceride, cholesterol, HDL and LDL were measured. Liver MDA, GSH, CAT, SOD and TNF-α were evaluated. Histological examination was performed. The rats treated with TAA showed a significant increase in AST, ALT, GGT, total bilirubin, creatinine, urea, uric acid, total, triglyceride, cholesterol and HDL while it led to a significant decrease in protein and HDL. The treatment of rats with TAA resulted in a significant decrease of the hepatic GSH, SOD and CAT and a significant elevation of MDA and TNF-α. Allium porrum and Bauhinia variegata extracts alleviated the toxic effects of TAA on the liver and the kidney. In conclusion, treatment with Allium porrum and Bauhinia variegata extracts and their combination reduced deleterious effects of TAA on liver through antioxidant and anti-inflammatory properties.

Structural characterisation of malonyl flavonols in leek (Allium porrum L.) using high-performance liquid chromatography and mass spectrometry.

INTRODUCTION: Vegetables contain a variety of phytochemicals that have the ability to modify enzymatic and chemical reactions, and therefore may have a positive influence on human health. In particular kaempferol is known to possess anti-carcinogenic activity. OBJECTIVE: The purpose of this work was to determine the structure of glycosylated kaempferol derivatives, acylated with malonic acid on the sugar portion. METHODS: A methanolic extract of the leaves of Allium porrum L. was submitted to fractionation procedures through semi-preparative HPLC/UV-MS techniques. The collected fractions were evaluated by accurate tandem mass spectrometry experiments using an electrospray ionisation (ESI) quadrupole time-of-flight instrument. Isolated compounds were hydrolysed in order to obtain information on the ester moieties. RESULTS: The structures of five compounds not previously reported in leek were determined. The molecules are mono-hexose, di-hexose and coumaroyl, feruloyl and caffeoyl acylated di-hexose derivatives of kaempferol. The common characteristic of the structures relies on the presence of the malonyl moiety on the primary alcoholic function of the sugar immediately linked to the aglycone. Accurate tandem MS experiments and basic hydrolysis treatments revealed a sequence of the acylated glycosidic moieties. CONCLUSION: A set of secondary metabolites of the aerial part of Allium porrum L. (leek) was identified and characterised by ESI/MS(2) . Knowledge of the presence of these first-reported compounds in leek could provide the means for fully understanding of the metabolism of this plant in relation to the biosynthesis of the phenolics.

Metabolite profiling of leek (Allium porrum L) cultivars by (1) H NMR and HPLC-MS.

INTRODUCTION: Leek (Allium ampeloprasum var. porrum) is consumed as a vegetable throughout the world. However, little is known about the metabolites of leek cultivars, especially those with potentially important beneficial properties for human health. OBJECTIVE: We provide new information for the overall metabolite composition of several leek cultivars grown in Europe by using HPLC-MS and (1) H NMR. METHODS: The use of a novel CTLS/NMR (constrained total-line-shape nuclear magnetic resonance) approach was found to be capable of reliable quantification, even with overlapping metabolite signals in the (1) H NMR of plant metabolites. Additionally, a new application for leek flavonoids was optimised for HPLC-MS. RESULTS: The total concentration of carbohydrates (glucose, fructose, kestose/nystose and sucrose) and nine amino acids varied by fourfold in leek juice from different cultivars, while the total concentrations of four organic acids were similar in all cultivars. All the quantified flavonols were kaempferol derivatives or quercetin derivatives and threefold differences in flavonol concentrations were detected between cultivars. CONCLUSION: In this study, various phytochemical profiles were determined for several leek cultivars by (1) H NMR spectroscopy with CTLS combined with HPLC-MS. The wide variation in bioactive compounds among commercial leek cultivars offers promising opportunities for breeders to raise the levels of important biochemical compounds in leek breeding lines, and also provides some objective measure for quality assurance for the leek industry.

Glycan-directed SARS-CoV-2 inhibition by leek extract and lectins with insights into the mode-of-action of Concanavalin A.

Four years after its outbreak, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a global challenge for human health. At its surface, SARS-CoV-2 features numerous extensively glycosylated spike proteins. This glycan coat supports virion docking and entry into host cells and at the same time renders the virus less susceptible to neutralizing antibodies. Given the high genetic plasticity of SARS-CoV-2 and the rapid emergence of immune escape variants, targeting the glycan shield by carbohydrate-binding agents emerges as a promising strategy. However, the potential of carbohydrate-targeting reagents as viral inhibitors remains underexplored. Here, we tested seven plant-derived carbohydrate-binding proteins, called lectins, and one crude plant extract for their antiviral activity against SARS-CoV-2 in two types of human lung cells: A549 cells ectopically expressing the ACE2 receptor and Calu-3 cells. We identified three lectins and an Allium porrum (leek) extract inhibiting SARS-CoV-2 infection in both cell systems with selectivity indices (SI) ranging between >2 and >299. Amongst these, the lectin Concanavalin A (Con A) exerted the most potent and broad activity against a panel of SARS-CoV-2 variants. We used multiplex super-resolution microscopy to address lectin interactions with SARS-CoV-2 and its host cells. Notably, we discovered that Con A not only binds to SARS-CoV-2 virions and their host cells, but also causes SARS-CoV-2 aggregation. Thus, Con A exerts a dual mode-of-action comprising both, antiviral and virucidal, mechanisms. These results establish Con A and other plant lectins as candidates for COVID-19 prevention and basis for further drug development.

Effects of different preparation and cooking processes on the bioactive molecules of Allium vegetables.

Allium species are among the most widely cultivated vegetables for centuries for their positive effects on human health and their variety of uses in food preparation and cooking. Preparation and cooking processes create chemical changes that can affect the concentration and bioavailability of bioactive molecules. Understanding the changes in bioactive compounds and bioactive activities in Allium vegetables resulting from preparation and cooking processes is essential for better retention of these compounds and better utilization of their health benefits. This study aimed to investigate the effects of different preparation and cooking processes on the bioactive molecules of Allium vegetables. This review concludes that bioactive compounds in Allium vegetables are affected by each preparation and cooking process depending on variables including method, time, temperature. Owing to differences in the matrix and structure of the plant, preparation and cooking processes show different results on bioactive compounds and bioactive activities for different vegetables. Continued research is needed to help fill gaps in current knowledge, such as the optimal preparation and cooking processes for each Allium vegetable.

Optimizing Spinosyn Insecticide Applications for Allium Leafminer (Diptera: Agromyzidae) Management in Allium Crops.

Allium leafminer, Phytomyza gymnostoma Loew (Diptera: Agromyzidae), is an invasive pest of allium crops in North America. Spinosyn insecticides, spinetoram and spinosad, have been effective choices for managing P. gymnostoma infestations in allium crops, but their use should be optimized for economical and resistance management purposes. In New York from 2018 through 2020, performance of each spinosyn insecticide was evaluated by making two applications spaced either 1 or 2 wk apart beginning at various intervals after P. gymnostoma was first detected in the field; a weekly spray program also was included. Results indicated that weekly applications of each spinosyn insecticide provided ≥98% reduction of P. gymnostoma densities in scallions and leeks relative to the untreated control. Spinetoram applied twice, regardless of initial timing and duration between sprays, provided an acceptable level of P. gynostoma control (71 to 98% reduction in densities relative to the untreated control). Spinosad also was effective when applied twice (85 to 95% reduction in densities relative to the untreated control), but not when sprays were made consecutively beginning when P. gymnostoma was first detected and not when the P. gymnostoma infestation was extremely high (i.e., 38 insects per plant in the untreated control). Management of P. gymnostoma with spinosyns can be successful with only two applications, but control tended to be best when first applied 2 to 3 wk after initial detection. Optimizing applications of spinetoram and spinosad will save growers time, reduce insecticide costs, and mitigate resistance development without significantly increasing the risk of yield reduction.

Bioaccessibility and bioavailability of selenium species in Se-enriched leeks (Allium Porrum) cultivated by hydroponically.

The Allium genus vegetables are of special interest since being potentially sources for selenium. In this study, the metabolization of selenite and selenate fortification at low and high levels in hydroponically cultivated Allium porrum (Leek) was investigated. The total Se analysis of nutritional solutions which was used in cultivation medium revealed that leeks had potential to accumulate Se above over 1000 mg/kg without any growth disturbance which was proved by comparing dry masses of control group with the ones fortified by Se species. Speciation analyses performed in edible parts which are leaves and stems showed that approximately 90% of total selenium was biotransformed into organo-selenium species in which MeSeCys and SeMet were found to be the most dominant in Se(IV) fortified leeks. However, selenate was found to be the most abundant species in edible parts of selenate fortified leeks especially at high levels. Although bioavailability rate of total selenium in selenate fortified leeks was found to be higher, lower amount of inorganic selenium and higher amount of MeSeCys were found to be bioavailable in Se(IV) fortified.

Managing Allium Leafminer (Diptera: Agromyzidae): An Emerging Pest of Allium Crops in North America.

Allium leafminer, Phytomyza gymnostoma Loew, is the newest invasive pest of allium crops in North America. Larvae initially feed in the upper canopy before mining toward the base of the plant to pupate. Crop loss occurs when larvae destroy vascular tissue, facilitating infection by bacterial and fungal pathogens that cause rot. Contamination also occurs when larvae and pupae are present at harvest. In response to this invasion, efficacy of 14 insecticide active ingredients applied via foliar sprays, transplant treatments, and drip chemigation was evaluated for managing P. gymnostoma. Multiple field studies were conducted in onions, leeks, and scallions in Pennsylvania and New York, United States in 2018 and 2019. The highest and most consistent levels of P. gymnostoma control occurred using foliar applications of dinotefuran, cyantraniliprole and spinetoram (84-89% reduction in damage; 95% reduction in P. gymnostoma densities). Despite the success of dinotefuran and cyantraniliprole applied as foliar sprays, neither was effective in controlling P. gymnostoma when administered via drip chemigation. Other foliar-applied insecticides that significantly reduced densities of P. gymnostoma in one or two experiments included abamectin, acetamiprid, cyromazine, imidacloprid, lambda-cyhalothrin, methomyl, and spinosad. Active ingredients that never controlled P. gymnostoma included azadirachtin, kaolin clay, pyrethrin, and spirotetramat. Spinosad applied to bare-root and plug-tray transplants immediately before transplanting reduced P. gymnostoma damage in the field by >90%. Implications of using these insecticides and application strategies are discussed within the context of developing a sustainable IPM program.

Characterization of the complete chloroplast genome of leek Allium porrum L. (Amaryllidaceae).

The complete chloroplast genome sequence of Allium porrum was determined by Illumina single-end sequencing. The complete plastid genome was 152,732 bp in length containing a large single copy (LSC) of 81,744 bp and a small single copy (SSC) of 17,910 bp, which were separated by a pair of 26,524 bp inverted repeats (IRs). A total of 133 genes were annotated, including 80 protein-coding genes, 38 tRNA genes, 8 rRNA genes, and 7 pseudogenes. The overall GC contents of the plastid genome were 36.7%. Unlike A. sativum and A. obliquum in the leek, plastome infA gene is absent, and rpl23 gene is a pseudogene due to a 4 bp deletion and the formation of a premature stop codon.

Allium porrum Extract Decreases Effector Cell Degranulation and Modulates Airway Epithelial Cell Function.

Allium genus plants, such as leek (Allium porrum), are rich sources of anti-inflammatory and anti-oxidant secondary metabolites; this is of interest because it demonstrates their suitability as pharmacological alternatives for inflammatory processes, including allergy treatment. The composition of methanolic leek extract (LE) was analyzed by GC-MS and LC-IT/MS, and the total phenolic content and antioxidant capacity were quantified by colorimetric methods. Its pharmacological potential was analyzed in human bronchial epithelial Calu-3 cells, human mast cells LAD2, and humanized rat basophiles RBL-2H3. LE exhibited a cytotoxic effect on Calu-3 cells and HumRBL-2H3 cells only at high concentrations and in a dose-dependent manner. Moreover, LE decreased the degranulation of LAD2 and HumRBL-2H3 cells. LE treatment also significantly prevented alterations in transepithelial electrical resistance values and mRNA levels of glutathione-S-transferase (GST), c-Jun, and NFκB after treatment with H2O2 in ALI-cultured Calu-3 cells. Finally, ALI-cultured Calu-3 cells treated with LE showed lower permeability to Ole e 1 compared to untreated cells. A reduction in IL-6 secretion in ALI-cultured Calu-3 cells treated with LE was also observed. In summary, the results obtained in this work suggest that A. porrum extract may have potential anti-allergic effects due to its antioxidant and anti-inflammatory properties. This study provides several important insights into how LE can protect against allergy.

The development of endomycorrhizal root systems: VII. A detailed study of effects of soil phosphorus on colonization.

Leek plants (Allium porrum L.) were grown in a controlled environment on a mixture (2: 1 w/w) γ-irradiated (1.0 Mrad) sandy loam and sand, at six concentrations of bicarbonate-soluble phosphorus (P) ranging from 22 to 344 mg P kg-1 (soil basis). Inoculum of the vesicular-arbuscular (VA) mycorrhizal fungus Glomus mosseae (Nicolson & Gerdemann) Gerdemann and Trappe was placed (M) or not (NM) in a layer 3 cm below the soil surface. At intervals of 10 d, lengths of main axes of roots and their lateral branches, and of the segments of infection within them, were measured. From these data we calculated the mean (harvest interval method} rates of linear extension of root tips and of infection fronts for each member of root, averaged over the whole root system. The mean delay, d, between a root encountering the layer of inoculum and the subsequent formation of internal infection, was also derived. Addition of P to soil did not affect rates of extension of roots, but increased the initiation of main axes and laterals. Infection segments extended twice as fast in laterals as in main axes. At low rates of addition, P did not affect fungal behaviour but increased the length of root available for colonization. When bicarbonate-soluble P exceeded 140 mg kg-1 , the rates of extension of infection fronts in both main axes and laterals were approximately halved, and d was considerably increased. The density (the area ratio of fungal to host tissue in a longitudinal squash) of the hyphae and arbuscules respectively, and the number of entry points per unit length of root, were greatly reduced by added P. However, the ratios of numbers of entry points/hyphal density and of arbuscule density/hyphal density were unaltered, and the morphology of the fungus was not noticeably affected. It is probable that formation of entry points was the rate-limiting step for colonization, and that this rate was reduced by added P.

Effects of Intercropping on Growth and Reproductive Capacity of Late-emerging Senecio vulgaris L., with Special Reference to Competition for Light.

Due to increased emphasis on long-term management of weed populations in cropping systems with a reduced reliance on herbicides, the production of seeds by weeds that emerge after the critical period for weed control is increasingly important. It was hypothesized that increased soil cover and light interception by a crop canopy would shorten the critical period for weed control and reduce growth and fecundity of late-emerging weeds. This hypothesis was tested in a series of field and glasshouse experiments in which competition for light was manipulated. Senecio vulgaris , an important weed in vegetable production systems, was chosen as the target plant, and canopies of pure and mixed stands of leek and celery were used to provide shade. The time course of light interception differed among the crop canopies. Increasing competition for light caused morphological changes to S. vulgaris , including a vertical shift in leaf area distribution. Increased shading reduced biomass, capitula:shoot ratio and seed production of S. vulgaris . However, the viability of seeds produced by the shaded weed plants was not affected. Results indicate that intercropping can increase light interception in a weakly competitive crop such as leek and can contribute to weed suppression in a long-term strategy for weed management.