Onion Root Research Articles

A turn-on anthraquinone-derived colorimetric and fluorometric dual-mode probe for highly selective Hg2+ determination and bioimaging in living organisms

Mercury ion (Hg2+) is considered a harmful neurotoxin, and real-time monitoring of Hg2+ concentrations in environmental and biological samples is critical. Fluorescent probes are a rapidly emerging visualization tool owing to their simple design and good selectivity. Herein, a novel fluorescence (FL) probe 2-(4-((6-((quinolin-8-yloxy)methyl)pyridin-2-yl)methyl)piperazin-1-yl)anthracene-9,10-dione (QPPA) is designed using piperazine as a linker between the anthraquinone group, which serves as a fluorophore, and N4O as the Hg2+ ligand. The probe exhibits FL “turn-on” sensing of Hg2+ because the complex inhibits the photo-induced electron transfer (PET) process. Moreover, QPPA can overcome the invasion by other possible cations, resulting in a clear color change from orange to colorless with the addition Hg2+. The chelation of QPPA with Hg2+ in a 1:1 ratio. Subsequently, the theoretically determined binding sites of the ligand to Hg2+ are validated through 1H NMR titration. The in situQPPA–Hg2+ complex can be subjected to Hg2+ extraction following the introduction of S2− owing to its robust binding capacity. The exceptional limit of detection values for Hg2+ and S2− are obtained as 63.0 and 79.1 nM (S/N = 3), respectively. Moreover, QPPA can display bright red FL in the presence of Hg2+ in different biological specimens such as HeLa cells, zebrafish, onion root tip tissues, and water flea Daphnia carinata, further providing an effective strategy for environmental monitoring and bioimaging of Hg2+ in living organisms.

Evaluating the role of soil EPS in modifying the toxicity potential of the mixture of polystyrene nanoplastics and xenoestrogen, Bisphenol A (BPA) in Allium cepa L.

The coexistence of emerging pollutants like nanoplastics and xenoestrogen chemicals such as Bisphenol A (BPA) raises significant environmental concerns. While the individual impacts of BPA and polystyrene nanoplastics (PSNPs) on plants have been studied, their combined effects are not well understood. This study examines the interactions between eco-corona formation, physicochemical properties, and cyto-genotoxic effects of PSNPs and BPA on onion (Allium cepa) root tip cells. Eco-corona formation was induced by exposing BPA-PSNP mixtures to soil extracellular polymeric substances (EPS), and changes were analyzed using 3D-EEM, TEM, FTIR, hydrodynamic diameter, and contact angle measurements. Onion roots were treated with BPA (2.5, 5, and 10 mgL-1) combined with plain, aminated, and carboxylated PSNPs (100 mgL-1), with and without EPS interaction. Toxicity was assessed via cell viability, oxidative stress markers (superoxide radical, total ROS, hydroxyl radical), lipid peroxidation, SOD and catalase activity, mitotic index, and chromosomal abnormalities. BPA alone increased cytotoxic and genotoxic parameters in a dose-dependent manner. BPA with aminated PSNPs exhibited the highest toxicity among the pristine mixtures, revealing increased chromosomal abnormalities, oxidative stress, and cell mortality with rising BPA concentrations. In-silico experiments demonstrated the relationship between superoxide dismutase (SOD), catalase enzymes, PSNPs, BPA, and their mixtures. EPS adsorption notably reduced cyto-genotoxic effects, lipid peroxidation, and ROS levels, mitigating the toxicity of BPA-PSNP mixtures.

Insights into bioactive constituents of onion (Allium cepa L.) waste: a comparative metabolomics study enhanced by chemometric tools

BackgroundOnion waste was reported to be a valuable source of bioactive constituents with potential health-promoting benefits. This sparked a surge of interest among scientists for its valorization. This study aims to investigate the chemical profiles of peel and root extracts of four onion cultivars (red, copper-yellow, golden yellow and white onions) and evaluate their erectogenic and anti-inflammatory potentials.MethodsUPLC-QqQ-MS/MS analysis and chemometric tools were utilized to determine the chemical profiles of onion peel and root extracts. The erectogenic potential of the extracts was evaluated using the PDE-5 inhibitory assay, while their anti-inflammatory activity was determined by identifying their downregulating effect on the gene expression of IL-6, IL-1β, IFN-γ, and TNF-α in LPS-stimulated WBCs.ResultsA total of 103 metabolites of diverse chemical classes were identified, with the most abundant being flavonoids. The organ’s influence on the chemical profiles of the samples outweighed the influence of the cultivar, as evidenced by the close clustering of samples from the same organ compared to the distinct separation of root and peel samples from the same cultivar. Furthermore, the tested extracts demonstrated promising PDE-5 and anti-inflammatory potentials and effectively suppressed the upregulation of pro-inflammatory markers in LPS-stimulated WBCs. The anti-inflammatory activities exerted by peel samples surpassed those of root samples, highlighting the importance of selecting the appropriate organ to maximize activity. The main metabolites correlated with PDE-5 inhibition were cyanidin 3-O-(malonyl-acetyl)-glucoside and quercetin dimer hexoside, while those correlated with IL-1β inhibition were γ-glutamyl-methionine sulfoxide, γ-glutamyl glutamine, sativanone, and stearic acid. Taxifolin, 3’-hydroxymelanettin, and oleic acid were highly correlated with IL-6 downregulation, while quercetin 4’-O-glucoside, isorhamnetin 4’-O-glucoside, and p-coumaroyl glycolic acid showed the highest correlation to IFN-γ and TNF-α inhibition.ConclusionThis study provides a fresh perspective on onion waste as a valuable source of bioactive constituents that could serve as the cornerstone for developing new, effective anti-PDE-5 and anti-inflammatory drug candidates.

Cytogenotoxicity of 2,4-D and Glyphosate Herbicides: Effects of Isolated and Combined Environmental Concentrations on Onion Root Tips (Allium Cepa)

Cytogenotoxicity of 2,4-D and Glyphosate Herbicides: Effects of Isolated and Combined Environmental Concentrations on Onion Root Tips (Allium Cepa)

Approach regarding the biosafety evaluation of black and red currant pomace extracts using Allium cepa test

Abstract In the present work, biosafety evaluation of black and red currant pomace extracts was conducted using in vivo plant test system, such as Allium cepa, a sustainable method which can provide valuable information on the cytotoxic and genotoxic effect of extracts from natural sources in relation with their phytochemical composition. In this view, different aqueous and hydroethanolic extractions from black and red currant pomaces were carried out. For revealing the differences in the phytochemical profile of the studied extracts, rapid, efficient and easy-to-operate analytical techniques such as colorimetry, UV-Vis spectrometry and electrometry were used. Cytogenetic analysis of pomace extracts was achieved using Allium cepa test by scoring the mitotic index, the limit value of cytotoxicity, the phase index of mitosis and presence of chromosomal aberrations for all samples and comparing to the control (tap water). The results have shown that the cytogenetic response depends both on the type of pomaces and on the experimental extraction conditions. Compared to the control sample (22.58 %), a decrease in mitotic index for each analyzed sample was observed. As well, an increase in the cells with chromosomal aberrations was detected in onion root tips exposed to the tested extracts compared to the control (0.69 %). The lowest value of mitotic index (12.44 %) and the highest value of chromosomal aberrations (1.91 %) were recorded from the root tip cells of onion bulbs exposed to the hydroalcoholic extract obtained from red currants pomace using water/ethanol (60:40 v/v). Even if the mitotic index decreased, the limit value of cytotoxicity was higher than 50 %, level considered as a sublethal condition for the organisms. At the same time, the increase of the frequency of chromosomal aberrations is not so significant, and in correlation with the cytotoxicity limit, it does not indicate a genotoxic effect on onion cells. Following these results, it can be concluded that black and red currant pomace extracts can be safely used for possible therapeutic benefits.

Effect of sewage wastewater on the mitotic index of the root tips of Allium cepa in koya city /Kurdistan region of Iraq

The purpose of the experiment was to investigate onion (Allium cepa) root growth, cell division, and mitotic index. The onions were placed into four different water samples (Control water, Azadi bridge, Sar Razan, and Sar Baskan) for 72 hours in beakers. The results showed that the number of divided cells decreased significantly in the sewage water compared with the control water. The control water had a high percentage of divided cells (18%), whereas the Sar Razan sewage water had the least percentage of divided cells (1.3%). The percentage of divided cells in Sar Baskan sewage water was 2%, and the percentage of divided cells in Azadi Bridge was 2.6%. It was found that the mitotic index and the number of divided cells increased in the control water compared to the sewage water. The results showed that sewage water has a greater impact on root growth, cell division, and mitotic index of root tips of Allium cepa.

Evaluation with physiological, cytogenetic, biochemical and anatomical aspects of dose-dependent inhibitory activity of jasmonic acid, a lipidderived growth regulator, in onion root tip cells

The effects of different doses of exogenous jasmonic acid (JA), were investigated on physiological parameters such as germination percentage, root length, root number and fresh weight, cytogenetic parameters such as mitotic index (MI), micronucleus (MN), frequency and chromosome aberration (CA), biochemical parameters as such superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and proline (PR) contents of Allium cepa L., known as onion. In addition, the changes in the root anatomical structures of the bulbs were examined under the microscope by taking cross-sections. Onion bulbs were divided into four groups as one control (C) and three treatments. The bulbs of the C group were kept in cuvettes containing tap water for 7 days and the bulbs of the treatment groups were kept in cuvettes containing 100 µM, 250 µM and 500 µM JA. JA administration caused a decrease in all physiological parameters examined, an increase in the frequency of MN and CA, and a reduce in MI compared to group C. In addition, the mentioned application caused a dosedependent increase in CAT and SOD activities and MDA and PR contents compared to group C. Moreover, 500 µM JA, the highest application dose, caused quite significant damages such as giant cell nucleus, unclear vascular tissue, binuclealar cell and accumulation of some substances in the cells of the epidermis/cortex in root anatomical structure of the bulbs. In summary, it was concluded that JA is a chemical with inhibitory functions and the Allium cepa test is a useful bioindicator for monitoring these effects.

Elemental Composition, Antioxidant, Anti-inflammatory and Anti-genotoxic Properties of Nitophyllum punctatum

ObjectivesMarine algae are important sources of nutritionally and pharmacologically important products. Here in the study, nutritional composition and biological activities of a marine red algae Nitophyllum punctatum were assessed. The present study aimed to analyze the nutritional composition and biological effects of the N. punctatum. MethodsThe marine algae N. punctatum was collected, shade dried and extracted using Soxhelet apparatus. The elemental composition was estimated using Atomic Absorption Spectroscopy; the anti-inflammatory effect was determined using Raw 264.7 macrophages. Genotoxicity was assessed by standard methods using Allium cepa root model. ResultsThe elemental composition analysis revealed the presence of essential minerals such as calcium, magnesium, potassium, and iron, indicating the potential nutritional value of the algae. The extract demonstrated significant inhibition of Nitric oxide (NO) production and downregulated the expression of pro-inflammatory cytokines such as TNF-α and IL-6, suggesting its potential as an anti-inflammatory agent. Furthermore, the anti-genotoxic potential of the methanol extract was evaluated using the Allium cepa model, a well-established system for assessing genotoxicity. Onion root tips were treated with various concentrations of the extract, and the chromosomal changes were performed as indicators of genotoxicity. Results indicated a protective effect against Ethyl methyl sulfonate (EMS) induced genotoxicity in onion roots. ConclusionsThe findings suggest that the methanol extract of N. punctatum possesses potent anti-inflammatory and anti-genotoxic properties, which may be attributed to the presence of bioactive compounds. The study highlights the potential pharmacological importance of N. punctatum as a source of natural compounds with anti-inflammatory and anti-genotoxic activities.

Hazard assessment and cytogenotoxic effect of different concentrations of mercury chloride sterilant using the Allium cepa assay

The Allium cepa assay represents a crucial in vivo model for evaluating the cytotoxicity and genotoxicity of substances. This study investigated the cytogenotoxicity of mercury chloride (HgCl2), a laboratory disinfectant and catalyst, using the Allium cepa assay. Mitotic slides were prepared from onion root tip cells grown on media supplemented with different concentrations of HgCl2 (0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). The slides were observed to evaluate cytogenotoxicity based on the assessment of the mitotic index, mitotic inhibition, clastogenic effect, and root length. The results showed that the concentrations used are harmful to the cell, leading to adverse impacts on the mitotic index, mitotic inhibition, root growth, and chromosome structure. Different chromosomal aberrations, such as bridge formation, fragmentation fragments, wandering chromosomes, stickiness, binucleate cells, and micronucleus formation, were detected depending on the concentration. Although lower concentrations (0.2–0.4%) had fewer effects on the cells, they still had a significant cytogenotoxic effect (p < 0.05) compared to that of the control (0.0%). The higher the concentration, the greater the effects on clastogenic changes. The abnormalities in both mitotic spread and root growth indicate that mercury chloride is cytotoxic even at low concentrations and can cause mito-depressive effects at higher concentrations. The results of this investigation can be used as a guide to guarantee sufficient safety precautions for people and organs during the regular use of HgCl2.

Total aerobic plate count and onion (Allium cepa) root tip assay using banana (Musa acuminata x balbisiana) Pseudostem accumulated water with thin-layer chromatography as confirmatory test

Cancer is a group of diseases characterized by the uncontrolled growth of abnormal cells. It can originate from any of the trillions of cells in the human body. Normally, cells grow and divide as needed, but cancer disrupts this process, causing abnormal cells to multiply uncontrollably. According to Monda et al. (2021), the pseudostem of the banana tree possess anticancer activities due to the phytochemicals present, which is why the researchers want to determine whether the accumulated water inside the banana pseudostem also holds the potential to become an alternative anti-cancer treatment. The researchers utilized total aerobic plate counting and Allium cepa root tip assay for the researchers to evaluate the potability of the banana pseudostem accumulated water and assess its inhibitory properties for cell growth, respectively. Based on the findings of the study, the total number of aerobic plates is too numerous to be counted (TNTC) and from the ANOVA analysis conducted, there was no significant difference among the cell growth inhibition. To verify this result, thin-layer chromatography was used to determine if there are any phytochemicals present within the sample possessing anticancer properties. No phytochemicals with such characteristics were identified. In conclusion, the banana pseudostem accumulated water is not a suitable alternative for anticancer medications. The researchers recommended considering other factors that might affect the quality of the sample. They also suggested subjecting the data to a more in-depth analysis, such as examining the Mitotic Index and chromosomal aberrations, to obtain more specific information.

Extraction and characterization of carotenoid pigments with antioxidant and antibacterial potential from marine yeast Rhodotorula sp. KSB1.

Pigments are coloring agents used widely in different industrial sectors. There is a demand for using natural pigments rather than synthetic dyes because of the health hazards caused by synthetic dyes. Many natural pigments have different medicinal activities which can contribute to the nutritional value of the product. This study was carried forward with marine yeasts which can produce pigments. A total of 4 marine yeast isolates were recovered from the mangrove area of Sundarbans, West Bengal, India. Among them, the isolate KSB1 produced 856µg/g total concentration of carotenoid pigment and the dry mass weight was 3.56g/L. The stability of the extracted pigments was checked using temperature, pH, UV light exposure time, and different saline conditions. The pigments were characterized using HPLC and FTIR analysis. All of the extracted pigments showed good antioxidant activity in DPPH, metal chelating, and reducing power assay. The pigments were also found to have good antibacterial activity against the bacterial pathogens Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. Carotenoid pigment from KSB1 was found to have maximum activity in all the pathogens. The cytogenotoxicity using onion roots and phytotoxicity analysis indicated that the pigments were non-toxic and safe for cells. Finally, the potential marine yeast was identified using 18s rRNA sequencing and identified as Rhodotorula sp. KSB1 (Accession no. MH782232).

The use of alternative coloring variations to mitotic observations of shallots using the squash method

Practicum cannot be carried out due to limited facilities and infrastructure such as dyes for observation of mitotic cell chromosomes in onions. Alternative dyes that can be obtained from nature can be explored. The purpose of this study was to obtain preparation of the mitotic division process in various onion root cells using alternative dyes using dyes from dragon fruit peel and turi flower. In obtaining the right preparation using the squash method. Data were obtained using observation sheets that observed each variation of the material. The instrument used in this study is a valid observation sheet. The results showed that the coloring of the preparation using dragon fruit skin and turi flowers was successful and clear coloring results were obtained. Coloring in practicum activities using turi flowers is better than dragon fruit coloring. Natural dyes from dragon fruit peel and turi flower can be used as alternative dyes in the squash method to observe onion root mitosis, replacing synthetic dyes.

Efecto antitoxicológico del tocosh de papa (Solanum tuberosum) frente al sulfametoxazol-trimetropina en raíces de cebolla (Allium cepa)

Varios fármacos de venta libre son ofrecidos a pacientes y no les alcanzan información de los efectos secundarios por su consumo frecuente. Ello estimuló a valorar el efecto antitoxicológico del tocosh de papa (Solanum tuberosum) frente al sulfametoxasol-trimetropina en raíces de cebolla (Allium cepa). Se desarrollaron raícillas de 3,0 cm en 20 bulbos de cebolla, las cuales se sostuvieron en cuatro procedimientos: testigo (100 ml de agua destilada), problema 1 (20 uL de tocosh), problema 2 (sulfametoxasol-trimetropina 1%) y problema 3 (sulfametoxasol-trimetropina 1% más 20 uL de tocosh.). Se aplicó la técnica de coloración de Tjio y Levan para la observación celular. El grupo 3 presentó: anomalías cromosómicas clastogénicas: puentes (2,3%), puentes múltiples (1,2%), cromosoma en c-metafase (0,5%) y aneugénicas: cromosoma pegajoso (1,1%) y yema nuclear (1,3%) y sin aberraciones (99,6%) mientras la agrupación que recibió antibiótico más tocosh expresó falta de anormalidades cromosómicas. En las condiciones de laboratorio, a una dosis de 2uL de tocosh se percibió el mejor efecto antitoxicológico en raicillas de Allium cepa lo cual muestra al tocosh como una alternativa antitoxicológica ante el poder tóxico de ciertos fármacos.

Exogenous application of mycotoxin fusaric acid improve the morphological, cytogenetic, biochemical and anatomical parameters in salt (NaCl) stressed Allium cepa L.

Salinity is one of the most important abiotic stress factors that negatively affect plant growth and development. In contrast, fusaric acid (FA), a mycotoxin produced by Fusarium and Giberella fungal genera, has biological and metabolic effects in various plants. In this study, it was aimed to investigate the protective effect of externally applied FA (0.1 nM) against the damage caused by salt (0.15 M NaCl) stress in onion (Allium cepa L.) plant. Salt stress resulted in an increase in the chromosomal aberrations (CAs) and micronucleus (MN) frequency, a decrease in the mitotic index (MI), fresh weight, root number, germination percentage, and root length. It promoted CAs such as irregular mitosis, bilobulated nuclei, chromosome loss, bridge, unequal seperation of chromosome, vagrant chromosome and polar slip in root meristem cells. In addition, salt stress caused a enhancement in free proline (PR), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the roots of onion plant. Moreover, it revealed damage and changes that include the accumulation of some chemical substances such as proline and sugars in epidermis and cortex layer cells, epidermal cell injury, flattening of the cell nucleus, wall thickening in cortex cells, necrotic areas and indistinct transmission tissue in the anatomical structure of onion roots. On the other hand, FA application promoted bulb germination and mitotic activity, strengthened the antioxidant defense system, and reduced chromosome and anatomical structure damages. In conclusion; it has been revealed that exogenous FA application may have a positive effect on increasing the resistance of onion plants to salt stress.

Removal of bentazone using activated carbon from spent coffee grounds

AbstractBACKGROUNDThis study aimed to produce activated carbon (AC) from spent coffee (Coffea arabica) grounds by chemical activation using zinc chloride (ZnCl2) and nitric acid to remove bentazone from aqueous solutions.RESULTSThe fresh spent coffee grounds were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and the AC by X‐ray diffraction (XRD), infrared spectroscopy (FTIR), Brunauer–Emmett– Teller (BET), point of zero charge, scanning electron microscopy (SEM) and the Boehman method. Adsorption experiments were carried out in a batch system. The results showed a 70% efficiency in bentazone removal using ZnCl2 carbon. Kinetic studies indicate that the adsorption rate increased slowly up to 720 min; the first‐ and second‐order models fitted the experimental data at a concentration of 50 mg L−1. The adsorption equilibrium is represented by the Langmuir model with a high adsorption capacity of 279.33 ± 6.29 mg mg−1. The adsorption efficiency was also confirmed by toxicity analysis of the effluent with bentazone at 50 mg L−1, using the Allium cepa bioassay, a high‐sensitivity test for pollutants in water.CONCLUSIONBefore adsorption, the effluent caused significant cytogenotoxicity to onion root meristems. After adsorption, the generated effluent no longer caused toxicity to the test system, and the results obtained were similar to the control with distilled water. © 2024 Society of Chemical Industry (SCI).

Role of aquaporins in micro-plastics accumulation in onion roots and the effects of micro-plastics on microtubules stability and organization under heat and salinity stress

Micro-plastics are emerging pollutants with a cosmopolitan distribution, and they are also well-known for their negative impacts on the terrestrial system. However, the effects of climate change factors such as - temperature and salinity stress on micro-plastics accumulation by plant roots and their toxicological behaviour in plants are unknown. In the present study, we deciphered how microplastics accumulation in onion roots changes under heat and salinity stress, affecting microtubules stability, organization, and water uptake by aquaporins. The fluorescence signal of nile-red stained micro-plastics in roots was detected with a marked reduction in the presence of aquaporins inhibitor – NaN3, showing the possible role of aquaporins in micro-plastics accumulation. It was further confirmed by changes in aquaporins genes expression. The acetylation of tubulin is an important post-translational modification that contributes to the stability of microtubule filaments. Micro-polystyrene effects on microtubules stability and organization were further aggravated by heat, but not salinity stress in accordance with ROS-level and antioxidant activity, indicating alarming risks of micro-plastics to the agro-ecosystem with global temperature rise.

Comparative Analysis of Polyphenol Content and Antioxidant Activity of Different Parts of Five Onion Cultivars Harvested in Korea.

Onions are typically consumed as the bulb, but the peel and root are discarded as by-products during processing. This study investigated the potential functional use of these by-products by analyzing the polyphenols, antioxidant compounds, and antioxidant activity contained in onions. In this study, the bulb, peel, and root of five onion cultivars ('Tank', 'Bomul', 'Gujji' 'Cobra', and 'Hongbanjang') harvested in Korea were investigated. Caffeic acid and quercetin were most abundant in the peel, whereas methyl gallate was the predominant polyphenol in the bulb. Both DPPH and ABTS radical scavenging activity were higher in onion peel and root than in the bulb. These findings suggest that onion peel and roots, which are often discarded, have abundant antioxidant substances and excellent antioxidant activity. This study provides basic data for the future use of onion peel and roots as functional ingredients with high added value.

The behavior of arsenic accumulation in onion (Allium cepa) structures by irrigation water: effect of phosphates and arsenic on the total bioactive compounds and antioxidant capacity.

The presence of arsenic (As) in irrigation water is a threat to agricultural crops as well as human health. The presence of arsenic and phosphorous in irrigation water influences the behavior of bioaccumulation, biotransfer, and total bioactive compounds in the distinct parts of the onion structure. The present work evaluates the behavior of the bioaccumulation and biotransfer of As in the structures of onion (Allium cepa) through a composite central design and response surface method. The factors employed include the concentration of arsenic (V) and phosphate (V) in the nutritive solution. Additionally, this study analyzes the behavior of the effect that the induced stress has on the total bioactive compounds (phenols and flavonoids) and antioxidant capacity (ABTS and DPPH) in the onion roots. The results showed that the physiological properties, bioaccumulation factors, As transference, and the total bioactive compounds in the onion structure are affected by the competition of As and phosphates (P(V)) in the irrigation water. For concentrations of As and phosphorous of 450 μg L-1 and 0.30 mg L-1 respectively in irrigation water, there are negative effects on the equatorial diameter of the bulb (DE), length, weight of the leaf, and weight of the bulb. Besides, the transference and bioaccumulation factors range from 0.02 to 0.22 and from 2.15 to 7.81, respectively, suggesting that the plant has the ability to accumulate As but exhibits a low translocation ability of As from the root to aerial organs. Besides, it is found for central concentrations of As and phosphorous (450 μg L-1 and 0.30 mg L-1, respectively) in irrigation water, a greater production occurs in total phenolic compounds and antioxidant capacity (ABTS and DPPH) as a response to the stress generated by As.

Microorganisms and algae (GEA soil) use in the cultivation of onion (Allium cepa L.) and garlic (Allium sativum L.)

Research objective: This research aims to evaluate the biostimulant potential of an innovative microbial product on the development of onion (Allium cepa L.) and garlic (Allium sativum L.) bulbs and roots under controlled conditions Materials and Methods: The experiments began in early July 2022 (mean temperature 22.5 °C), were carried out price experimental greenhouses of the CREA-OF of Pescia (Pt), Tuscany, on bulbs of onion (cv “Rossa di Tropea”) and garlic (cv “Bianco Polesano”). The bulbs were placed in pots ø 14 cm; 40 bulbs for thesis divided into replicas of 20 bulbs each, for all onion and garlic. The three experimental theses in cultivation were: i) group control irrigated with water and previously fertilised substrate; biofertiliser Ecklonia maxima irrigated with water and previously fertilised substrate; Gea soil (GEA) group irrigated with water and substrate previously fertilised. On 26 January 2024, bulbs weight, bulb diameter, roots weight, number of microorganisms were determined. In addition, the mortality of the bulbs in the nursery was assessed. Results and Discussion: The experiment showed that the use of biostimulants based on microorganisms and algae can significantly improve the size, weight and root growth of onion and garlic bulbs. In particular, the GEA soil thesis showed a significant increase in bulb length, weight and root growth compared to Ecklonia maxima and the untreated control thesis. There was also a significant increase in microbial colonisation of the substrate with GEA soil, a very interesting aspect that certainly had an effect on the growth of onion and garlic bulbs. The micro-organisms also by direct stimulation on the plants or by colonisation of the substrate significantly reduced bulb mortality in Gea soil, compared to BIOAL and the control. In recent years, horticulture has had to face the challenge of economic and environmental sustainability, reducing fertiliser use while adopting strategies to increase water use efficiency. Numerous forecasting models have shown that in the next 30 years many production areas could become semi-arid and among these is the Mediterranean basin, where many horticultural crops are grown. Increasing water use efficiency in this context appears essential for the development of sustainable horticulture. Many microorganisms or fungi can promote the plant's utilisation of nutrients and water in the soil. There are numerous strains of bacteria that promote root growth and are classified according to whether they act at the rhizosphere and rhizoplane level. Conclusions: Microbial biostimulants can be a valuable strategy to mitigate environmental stresses that have been emphasised by climate change in recent years. Microbial biostimulants, by increasing the biodiversity of the agro-ecosystem and creating long-lasting symbiotic relationships with the plant, are, in fact, a sustainable and effective solution to prevent the reduction in productivity caused by abiotic stresses and to optimise the use efficiency of human inputs in the agrarian ecosystem.

Influence of plant species, mycorrhizal inoculant, and soil phosphorus level on arbuscular mycorrhizal communities in onion and carrot roots.

Arbuscular mycorrhizal fungi (AMF) are ancient and ecologically important symbionts that colonize plant roots. These symbionts assist in the uptake of water and nutrients, particularly phosphorus, from the soil. This important role has led to the development of AMF inoculants for use as biofertilizers in agriculture. Commercial mycorrhizal inoculants are increasingly popular to produce onion and carrot, but their specific effects on native mycorrhizal communities under field conditions are not known. Furthermore, adequate availability of nutrients in soils, specifically phosphorus, can reduce the diversity and abundance of AMF communities in the roots. The type of crop grown can also influence the composition of AMF communities colonizing the plant roots. This study aimed to investigate how AMF inoculants, soil phosphorus levels, and plant species influence the diversity of AMF communities that colonize the roots of onion and carrot plants. Field trials were conducted on high organic matter (muck) soil in the Holland Marsh, Ontario, Canada. The treatments included AMF-coated seeds (three to five propagules of Rhizophagus irregularis per seed) and non-treated onion and carrot seeds grown in soil with low (~46 ppm) and high (~78 ppm) phosphorus levels. The mycorrhizal communities colonizing the onion and carrot roots were identified by Illumina sequencing. Five genera, Diversispora, Claroideoglomus, Funneliformis, Rhizophagus, and Glomus, were identified in roots of both plant species. AMF communities colonizing carrot roots were more diverse and richer than those colonizing onion roots. Diversispora and Funneliformis had a 1.3-fold and 2.9-fold greater abundance, respectively, in onion roots compared to carrots. Claroideoglomus was 1.4-fold more abundant in carrot roots than in onions. Inoculation with R. irregularis increased the abundance and richness of Rhizophagus in AMF communities of onion roots but not in carrot roots. The soil phosphorus level had no effect on the richness and diversity of AMF in the roots of either crop. In summary, AMF inoculant and soil phosphorus levels influenced the composition of AMF communities colonizing the roots of onion and carrot plants, but the effects varied between plant species.