The Accumulation Risk of Heavy Metals in Vegetables which Grown in Contaminated Soil

أجريت الدراسة الحالية لتقييم الحركة، التراكم الأحيائي ونقل المعادن الثقيلة (الحديد، الزنك، الكادميوم، النيكل، الكروم، المنجنيز، النحاس والرصاص) من التربة الملوثة إلى أنسجة الجذور ومن الجذور إلى الأجزاء الهوائية عن طريق حساب معامل التركيز الأحيائي وعامل الانتقال. جمعت عينات التربة والعينات النباتية لثمانية أنواع من الخضروات خلال موسم الصيف 2019 من أربعة مواقع مختلفة تقع في وادي الأرج ، محافظة الطائف ، المملكة العربية السعودية. بشكل عام ، سجلت عينات التربة المأخذوه من الموقع الثالث والرابع قيمًا مرتفعة من المعادن الثقيلة مقارنةً بالموقعين الأول والثاني. أظهرت التربة من الموقع الرابع أعلى تركيز من Mn و Ni و Cr و Pb و Cu و Cd بلغ 31.63 و 14.05 و 13.56 و 22.79 و 31.02 و 2.98 ملجم / كجم تربة جافة على التوالي ، بينما أظهرت التربة من الموقع الثالث أعلى تركيز للزنك. أشارت البيانات من الدراسة إلى أنه يمكن التعرف على نباتات الخس، النعناع، الشبث، الخيار، الفلفل والقرع التي نمت في مواقع الدراسة على أنها مناسبة للاستهلاك البشري، فهذه الخضروات الستة تراكم المعادن الثقيلة في أعضائها بكميات مقبولة بأقل من المستويات المسموح بها لمنظمة الأغذية والزراعة للأمم المتحدة. بخلاف ذلك، وجد أن تركيزات المعادن الثقيلة في نبات الطماطم ونبات الباذنجان أعلى من الحدود المسموح بها لمنظمة الأغذية والزراعة. الطماطم والباذنجان أيضاً أظهرت قيم عامل التركيز الأحيائي  مرتفعة لمعظم المعادن الثقيلة المقاسة. بالنسبة للطماطم كان معامل التركيز الأحيائي لكل من الكادميوم، النحاس، الحديد، الرصاص، المنجنيز، الزنك، الكروم والنيكل 27.250، 42.150، ،1.023، ND، 4.649، 0.459، 5.926 و 29.409 على التوالي. بينما كان في الباذنجان 21.333، ND، 2.360، 0.170، 3.113، 0.623، ND و 50.318 على التوالي.لتجنب الآثار الضارة لتراكم المعادن الثقيلة على صحة الإنسان ، يجب مراعاة الفحص المستمر للمحاصيل المزروعة في الترب الملوثة بالمعادن الثقيلة. أشارت البيانات من الدراسة إلى أنه يمكن التعرف على نباتات الخس، النعناع، الشبث، الخيار، الفلفل والقرع التي نمت في مواقع الدراسة على أنها مناسبة للاستهلاك البشري، فهذه الخضروات الستة تراكم المعادن الثقيلة في أعضائها بكميات مقبولة بأقل من المستويات المسموح بها لمنظمة الأغذية والزراعة. بخلاف ذلك، وجد أن تركيزات المعادن الثقيلة في نبات الطماطم ونبات الباذنجان أعلى من الحدود المسموح بها لمنظمة الأغذية والزراعة. الطماطم والباذنجان أيضاً أظهرت قيم عامل التركيز الأحيائي  مرتفعة لمعظم المعادن الثقيلة المقاسة. بالنسبة للطماطم قيم عامل التركيز الأحيائي لكل من الكادميوم، النحاس، الحديد، الرصاص، المنجنيز، الزنك، الكروم والنيكل كانت 27.250، 42.150، ،1.023، 0.000، 4.649، 0.459، 5.926 و 29.409 على التوالي. بينما كانت في الباذنجان 21.333، 0.000، 2.360، 0.170، 3.113، 0.623، 0.000 و 50.318 على التوالي. لا ينصح بزراعة الطماطم والباذنجان في التربة الملوثة بالمعادن الثقيلة بدون معالجة التربة مع ضرورة إجراء تحليل دوري للأجزاء الصالحة للأكل من الخضروات المزروعة في التربة الملوثة بالمعادن الثقيلة لمراقبة هذه المواد في النظام الغذائي البشري وتجنب آثاره الضارة على صحة الإنسان.The present study has been carried out to estimate heavy metals mobility, bioconcentration and transfer from polluted soil to roots tissues and from roots tissues to aerial parts using bioconcentration factor and translocation factor. Soil samples and the biomass of the eight vegetable species have been collected during summer season, 2019 from four different sites in Wadi Al-Arg, Taif Governorate, KSA. In general, heavy metals content of soil samples in site III and IV have recorded elevated values compared with those of site I and II. The soil from site IV has shown the highest concentration of Mn, Ni, Cr, Pb, Cu, and Cd amounted 31.63, 14.05, 13.56, 22.79, 31.02 and 2.98 mg/kg dry soil respectively, while the soil from site III has shown the highest concentration of Zn. The data referred to the fact that Mentha longifolia, Cucumis sativus, Capsicum annuum, Lactuca sativa Cucurbita pepo, and Anethum graveolens that grown in sites of investigation could be recognized as suitable for human consumption. These six vegetables could accumulate the measured heavy metals in their tissues with acceptable quantities, less than the permissible levels of Food and Agriculture Organization of the United Nations (FAO). Otherwise, heavy metal concentrations in Solanum lycopersicum and Solanum melongena have been found to be higher than permissible limits of FAO. Both plants also have shown elevated bioconcentration factors values for most of measured heavy metals. For S. lycopersicum the bioconcentration factor values of Fe, Cd, Cu, Pb, Cr, Mn, Ni, and Zn have been found to be 42.150, 27.250, 1.023, ND, 5.926, 4.649, 29.409, and 0.459 respectively. While for S. melongena, they have been 2.360, 21.333, ND, 0.170, ND, 3.113, 50.318, and 0.623, respectively. To avoid the harmful effects of the heavy metals accumulation on human health, consideration should be given to the constant examination to the edible parts of the vegetables grown in heavy metals contaminated soil

UV-C seed priming improves tomato plant growth against salt stress

The study aimed to evaluate the impact of UV-C dry seed priming at two doses (0.85 and 3.42 kJ.m−2), on tomato under salt stress (NaCl, 100 mM). Results show that salinity causes a regression of tomato growth by 63%, an accumulation of Na+ causing a reduction in K+ uptake and therefore an increase of photosynthetic processes (28, 28 and 23% for Chl. a, Chl. tot and Car., respectively), also an augmentation in soluble protein contents and a decrease or an increase in oxidative stress indicators and secondary metabolites depending on organs. UV-C seed priming has been shown to improve tomato growth by reducing the adverse effects of salinity on physiological and biochemical parameters. This research revealed that UV-C seed applications are an efficient approach to controlling the aggressiveness of salt stress on tomato roots and leaves. Specific doses of UV-C are required to trigger the physiological control of plants against salt stress

MOLECULAR IDENTIFICATION OF THE CULTIVATED MORNINGA OLEIFERA IN SAUDI ARABIA

ABSTRACT: Seven hundred and nine nucleotides spanning the ITS region (ITS1 and ITS2 and the highly conserved 5.8S rDNA exon located in between) and its flanking regions of small and large ribosomal DNA subunits (18S and 26S genes) were amplified and sequenced for Moringa oleifera seedlings. The obtained data have been analyzed by maximum-parsimony and neighbor-joining methods in order to identify the cultivated plant molecularly. The parsimony could not be discriminated between the cultivated taxon from either M. oleifera or M. peregrina. The tree showed clustering of the three species with 100% bootstrap supports without clear identification of the seedlings sample and the neighbor-joining method showed similar tree topology. The genetic distance obtained from the sequenced data indicated that the smallest distance was found between cultivated and wild M. oleifera and between wild M. oleifera and M. peregrina while the distance between the cultivated M. oleifera and M. peregrina was higher. The current data therefore identified the seedlings sample to be affected by the ecological habitat of Saudi Arabia which is considered as an endemic habitat of M. peregrina. Further molecular study is necessary by collecting more wild and cultivated samples of both species in order to identify with clear resolution the molecular relationship between both wild and cultivated Moringa

Effects of NaCl on Antioxidant, Antifungal, and Antibacterial Activities in Safflower Essential Oils

The present study aims to evaluate the antioxidant and antimicrobial activity of essential oils (EO) extracted from safflower plants grown in the absence and presence of NaCl, 50 mM. Plants treated with 50 mM of NaCl showed decreases in root, stem, and leaf dry weight. Results of the essential oils showed that roots have a higher EO yield than leaves and stems. Salinity caused a decrease in this yield in roots and leaves but not in stems. The compounds identified in the EO extracted from these organs belong to seven chemical classes of which the dominant class is the sesquiterpene hydrocarbons. The chemotype of C. tinctorius EO is variable depending on the organ and the treatment. The safflower essential oils showed low antioxidant, antiradical, and iron-reducing activities compared to those of the positive control (BHT). In an antifungal activity test, only two strains, Aspergillus niger and Candida albicans, were found to be highly sensitive to these oils as they showed almost total inhibition of their growth. For antibacterial activity, safflower EOs showed significant antimicrobial activity against Bacillus subtilis, Bacillus cereus, and Xanthomonas campestris in both control and NaCl-treated plants: for these three strains, total inhibition of growth was noted at 50,000 ppm of EO in leaves and roots; whereas for stems, total inhibition was noted only for the third strain (Xanthomonas campestris). For other strains, this inhibition was variable and weak. Salt was found to have no effect on the activities of safflower EOs

Mitigation of Salinity Stress in Maize Seedlings by the Application of Vermicompost and Sorghum Water Extracts

Abiotic stresses are important constraints limiting crop productivity worldwide. Salinity is one of the most devastating environmental factors restraining the production of crops. It is urgently needed to search for environmentally safe and sustainable approaches to mitigate the harmful effects of salinity on plants. Hence, applying vermicompost and low-dose aqueous extract of sorghum delivers a pragmatic solution to ameliorate the detrimental outcomes of salinity on maize seedlings (Zea mays L.). The experiment consisted of three factors, each at different levels, i.e., salinity (control, 6, and 12 dS m−1), vermicompost (control, 5, and 10%), and sorghum water extract (control, 1, and 2%). Higher salt stress negatively influenced the morpho-physiological traits of maize. Nonetheless, applying vermicompost and sorghum water extract at 10% and 2%, respectively, increased tolerance against salinity. The application of 2% sorghum water extract and 10% vermicompost significantly improved morphological characteristics, chlorophyll contents, activities of antioxidant enzymes, leaf and root K+/Na+ ratio, and K+ contents. It decreased Na+ concentration, H2O2, and malondialdehyde contents at higher salinity levels. It can be concluded that soil-applied vermicompost and foliar-applied sorghum water extract mitigates the adverse impacts of salinity by activating the antioxidant defense system, improving chlorophyll contents, and reducing the accumulation of Na+ under salinity

Biogenic nanoparticles application in agriculture for ROS mitigation and abiotic stress tolerance: A review

Plants have to face different abiotic stressors, such as extreme temperatures, drought, salinity, flood, and heavy metals, which negatively impact their growth and development, leading to lower agricultural productivity, food security concerns, and financial losses. Nanotechnology has emerged as a solution to mitigate these negative effects, improving resource use efficiency, reducing pollution, preventing plant diseases, and enhancing sustainability. Nanoparticles (NPs) apllication to agricultural crops addresses nutrient deficiencies, enhances stress tolerance, and improves crop yield and quality. Sustainable and environment friendly methods for synthesizing NPs have been developed over the last few decades. NPs possess distinct qualities and can serve as powerful sensors, controlling critical physiological and biochemical processes in plants. Furthermore, NPs offer unique mechanisms for adapting to changing climatic conditions. Abiotic stress generates reactive oxygen species (ROS), which cause oxidative stress and impairs redox homeostasis. The roles of ROS in signaling cascades and stress tolerance are gaining recognition. This review explores the potential of plant-based metallic and metallic oxide NPs to mitigate the harmful consequences of abiotic stresses induced excessive ROS. We have critically discussed green/biological synthesis methods of NPs, their potential roles in agriculture, and the mechanisms by which plant-based NPs can counteract ROS harmful effects on plant metabolism. Utilizing nanotechnology paves the way for sustainable crop cultivation, ensuring increased crop yields and enhanced environmental resilience

Effect of Potassium Deficiency on Physiological Responses and Anatomical Structure of Basil, <i>Ocimum basilicum</i> L.

The aim of this study was to investigate the effect of a variable supply of potassium to culture medium on physiological and anatomical parameters (histological sections at the third internode) in basil, Ocimum basilicum. Thirty-four-day-old plants grown on basic nutrient medium were divided into four batches and grown on media with varying doses of potassium: 0.375 mM, 0.250 mM, 0.125 mM and 0 mM K+. After 64 days of culture, a final harvest was performed. The results showed that root and shoot growth in basil was decreased with decreased K+ concentration. This restriction was associated with a reduction in root elongation and leaf expansion, which was coupled with a decrease in chlorophyll and carotenoid contents. The estimation of electrolyte leakage reveals that this parameter was increased by potassium deficiency. With respect to total polyphenol and flavonoid contents, only the third leaf-stage extracts exhibited a decrease under low-K+ conditions. However, variability in response of phenolic compounds was recorded depending on the organ and the K+ concentration in the medium. Stem cross sections of potassium-deficient basil plants revealed a decrease in the diameter of these organs, which can be attributed to a restriction of the extent of different tissue territories (cortex and medulla), as well as by a reduction in cell size. These effects were associated with a decrease in the number of conducting vessels and an increase in the number of woody fibers

Assessment of Health Risks in Wheat Crop Irrigated by Manka Canal, Dera Ghazi Khan, Pakistan

Background. Manka canal’s metal concentration rises from human activities’ garbage. Untreated water from the canal is used by farmers for local crop irrigation. Immediate action is crucial to assess heavy metal levels and ensure soil suitability for agriculture as metal pollution persists. Purpose. The current study was conducted to assess the health risks associated with metal pollution at Manka Canal, Dera Ghazi Khan. Methods. A total of eighty-four wastewater, soil, and wheat samples were collected from study areas. The collected samples were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, and Zn) using a flame atomic absorption spectrometer (FAAS). Results. The significant findings of the study revealed that the concentration of heavy metals in most of the collected samples of soil, water, and wheat was above the World Health Organization (WHO) permissible limits. The mean concentrations of Cd, Cu, Mn, Ni, Pb, and Zn were at relatively higher concentrations, i.e., 4.88, 22.03, 38.2, 89.2, 19.62, and 67.9 mg/kg, respectively, in collected wheat samples. The soil and irrigation water quality metrics had values that exceeded the acceptable thresholds, rendering them unfit for agricultural use. The local community faces an elevated health risk index for both children and adults due to the consumption of wheat crop as HRI is greater than 1 for nonessential elements like Cd and Pb. Conclusion. The study suggested that wastewater irrigation leads to the accumulation of heavy metals in foodstuffs, causing potential health risks to consumers. The gradual accumulation of these contaminants in biological systems finally gives rise to severe health-related issues. Therefore, it is crucial to implement robust wastewater treatment processes and stringent quality control measures to minimize health risks associated with the consumption of crops grown using reclaimed water. Prior to irrigating crops like wheat and vegetables, it is strongly advised to treat municipal wastewater to prevent soil and dietary toxicity from heavy metals

ZnO Nanoparticle-Mediated Seed Priming Induces Biochemical and Antioxidant Changes in Chickpea to Alleviate Fusarium Wilt

Chickpea (Cicer arietinum L.) is one of the main pulse crops of Pakistan. The yield of chickpea is affected by a variety of biotic and abiotic factors. Due to their environmentally friendly nature, different nanoparticles are being synthesized and applied to economically important crops. In the present study, Trichoderma harzianum has been used as a stabilizing and reducing agent for the mycosynthesis of zinc oxide nanoparticles (ZnO NPs). Before their application to control Fusarium wilt of chickpea, synthesized ZnO NPs were characterized. X-ray diffraction (XRD) analysis revealed the average size (13 nm) of ZnO NPs. Scanning electron microscopy (SEM) indicated their spherical structure, and energy dispersive X-ray analysis (EDX) confirmed the oxide formation of ZnO NPs. Transmission electron microscopy (TEM) described the size and shape of nanoparticles, and Fourier transform infrared (FTIR) spectroscopy displayed the presence of reducing and stabilizing chemical compounds (alcohol, carboxylic acid, amines, and alkyl halide). Successfully characterized ZnO NPs exhibited significant mycelial growth inhibition of Fusarium oxysporum, in vitro. In a greenhouse pot experiment, the priming of chickpea seeds with ZnO NPs significantly increased the antioxidant activity of germinated plants and they displayed 90% less disease incidence than the control. Seed priming with ZnO NPs helped plants to accumulate higher quantities of sugars, phenol, total proteins, and superoxide dismutase (SOD) to create resistance against wilt pathogen. These nanofungicides were produced in powder form and they can easily be transferred and used in the field to control Fusarium wilt of chickpea

First Report of Fruit Rot of Cherry and Its Control Using Fe2O3 Nanoparticles Synthesized in Calotropis procera

Cherry is a fleshy drupe, and it is grown in temperate regions of the world. It is perishable, and several biotic and abiotic factors affect its yield. During April&ndash;May 2021, a severe fruit rot of cherry was observed in Swat and adjacent areas. Diseased fruit samples were collected, and the disease-causing pathogen was isolated on PDA. Subsequent morphological, microscopic, and molecular analyses identified the isolated pathogen as Aspergillus flavus. For the control of the fruit rot disease of cherry, iron oxide nanoparticles (Fe2O3 NPs) were synthesized in the leaf extract of Calotropis procera and characterized. Fourier transform infrared (FTIR) spectroscopy of synthesized Fe2O3 NPs showed the presence of capping and stabilizing agents such as alcohols, aldehydes, and halo compounds. X-ray diffraction (XRD) analysis verified the form and size (32 nm) of Fe2O3 NPs. Scanning electron microscopy (SEM) revealed the spinal-shaped morphology of synthesized Fe2O3 NPs while X-ray diffraction (EDX) analysis displayed the occurrence of main elements in the samples. After successful preparation and characterization of NPs, their antifungal activity against A. flavus was determined by poison technique. Based on in vitro and in vivo antifungal activity analyses, it was observed that 1.0 mg/mL concentration of Fe2O3 can effectively inhibit the growth of fungal mycelia and decrease the incidence of fruit rot of cherry. The results confirmed ecofriendly fungicidal role of Fe2O3 and suggested that their large-scale application in the field to replace toxic chemical fungicides