STUDY OF LEAD ACCUMULATION IN PLANTS BY MEANS OF TOTAL REFLECTION XRAY FLUORESCENCE SPECTROSCOPY (original) (raw)
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Spectrochimica Acta Part B: Atomic Spectroscopy, 1997
Microwave assisted acidic digestion and total-reflection X-ray fluorescence spectrometry (TXRF) was used for the determination of lead and iron in wheat roots cultured in CaSO 4 solution, and treated with Pb(NO 3) 2 and Fe(III)-citrate or Fe(III)-EDTA under controlled conditions, respectively. It was established that lead has a stimulation effect on the iron uptake in the presence of Fe(III)-citrate. The lead uptake, however, is hardly influenced by iron independently from the complex forming agents applied. To check the stability of the accumulated iron and lead constituents, some of the roots were washed with various solutions and the removable iron and lead were also measured by TXRF. These experiments indicate that the presence of lead results in higher stability of iron constituents in the root; however, iron does not have any effect on the lead constituents, the stabilities of which increase in the order Pb-citrate Ͻ Pb-(cell wall) Ͻ Pb-EDTA. ᭧ 1997 Elsevier Science B.V.
Lead Uptake in Diverse Plant Families: A Study Applying X-ray Absorption Near Edge Spectroscopy
Environmental Science & Technology, 2013
The chemical environment of lead in roots and leaves of plants from four different plant families and a lichen from a former lead mining site in the Eifel Mountains in Germany was determined by Pb L 3-edge XANES measurements using solid reference compounds and also aqueous solutions of different ionic strength simulating the plant environment. Pb 2+ ions in the plants were found to have two major coordinations, one with nine oxygen atoms in the first coordination shell similar to outer-sphere complexation and a second coordination with just three oxygen atoms similar to inner-sphere complexation. This can be interpreted assuming that lead is sorbed on the surface of cell walls depending on the concentration of lead in the soil solution. Pb L 3-edge XANES spectra of dried and fresh plant samples are very similar because sorption does not change with removal of water but only because of the initial ionic strength. No bonding to biologically important groups (-S,-N) or precipitation (-PO 4) was found.
Journal of Photochemistry and Photobiology B: Biology, 2016
The responses of wheat seedling treated with silicon (Si; 10 μM) and lead (Pb; 100 μM) for 7 days have been investigated by analyzing growth, Pb uptake, chlorophyll fluorescence, oxidative stress, antioxidants and nutrients regulation. Results indicated that, Pb significantly (P b 0.05) declined growth of seedlings which was accompanied by uptake of Pb. Under Pb stress, fluorescence parameters: F v /F m ratio and qP were significantly (P b 0.05) decreased while NPQ was increased. Si addition alleviated Pb-induced decrease in growth and alterations in photosynthesis, and also significantly (P b 0.05) lowered Pb uptake. Under Pb treatment, oxidative stress markers: hydrogen peroxide and lipid peroxidation were enhanced while DPPH • scavenging capacity and total phenolic compounds (TPCs) were decreased significantly, however, Si addition improved the status of antioxidants. The non-protein thiols (NP-SH) showed enhanced level under Pb stress. Pb stress considerably disturbed status of the nutrients as decrease in Ca, P, Mg, Zn and Ni contents while an increase in K, S, B, Cu, Fe, Mn and Na contents were noticed. Si addition maintained status of all the nutrients remarkably. The quickest method of element analysis: LIBS spectra revealed significantly lower uptake of Pb in seedlings grown under Si and Pb combination and same was correlated with the data of AAS. Overall results pointed out that excess Pb uptake disturbed status of nutrients, photosynthetic performance, antioxidant capacity, hence severe oxidative damage to lipids occurred. Further, Si supplementation successfully regulated these parameters by inhibiting Pb uptake hence maintained growth of wheat seedlings. Similar pattern of data recorded by the LIBS, AAS and ICAP-AES confirmed that LIBS may be one of the promising and authentic tools to monitor the mineral and metal distribution in the plants without hampering or disturbing the environment due to its eco-friendly and non-invasive nature.
Radiation Physics and Chemistry, 2019
The phytoextraction technology uses vegetable species to extract toxic metals from contaminated soils and accumulate them in the harvestable parts of the plants, which can then be removed from site. The aim of this work was to perform a study by SR micro X-ray fluorescence technique of the spatial distribution of Pb in roots and leaves of two different species of plants potentially useful for soil phytoremediation. The experiments were conducted in Brassica napus and Festuca arundinacea. The plants were grown in Pb soil contaminated, in controlled environment, cultivated in greenhouses at CEPROCOR. The measurements were carried on at the D09B XRF Fluorescence beamline of the Brazilian Synchrotron Light Laboratory (LNLS), on different parts of the living plant. SR induced micro-XRF results showed that Brassica napus extracted Pb from the ground and translocated it to the leaves more effectively than Festuca arundinacea, grown in contaminated soil, where lead remained at the root. Furthermore, a co-distribution was observed between Pb and Zn, P, S and Fe. This suggest that Brassica napus is a potential plant to be used for phytoextraction of Pb from soil. The use of SR micro-XRF to map the distribution of metals in plant tissue allows significant advances in phytoremediation studies as well as in other topics of environmental sciences.
Asian Journal of Advanced Research and Reports, 2019
The samples of soil and selected species of vegetables (cowpea leaves, spinach, sweet potato leaves, Ethiopian mustard and Chinese cabbages) were randomly collected from four sites, Idara ya maji, Nkaiti, Mbulungu and Mkwajuni of Minjingu village of Manyara in Tanzania. The samples were analyzed by means of wavelength dispersive x-ray fluorescence (WDXRF) spectrometry to determine the heavy metal concentrations in soils and vegetables of the field study with emphasis on their health risk index (HRI) assessment. The results indicate that soils have concentration range of 142-1547 for Ca, 737-2515 for K, 2396-4748 for Si, 0-121 for P, 0-181 for Mg, 0-36 for S, 0-68 for Na, 561-942 for Al, 121-4748 for Fe, 0-80 for Mn, 0-53 for Sr, 0-37 for Cs and 0-11 for Ni in mg/kg which was above the maximum tolerable limits(MTL). Elements detected in vegetables were in the range of 2123-6122 for Ca, 747-8005 for K, 65-996 for Si, 40-348 for Mg, for Mn, 85-584 for P, 22-705 for S, 0-218 for Na, 70-835 for Fe, 23-286 for Al, 0-98 for Cs, 84-1076 for Cl and 0-13 for Ni in mg/kg. The highest heavy metal retention capability was exhibited in Cowpea leaves, Spinach and Chinese cabbages but sweet potato leaves and Ethiopian mustard has shown lower concentrations. Control site recorded the least concentration values. The HRI values for Sr, Ni and
A Mini Review on Lead (Pb) Toxicity in Plants
Journal of Biology and Life Science, 2015
Contamination of soil by various heavy metals is increasing day by day by different activities, such as industrialization and urbanization. Lead (Pb) is one of the potential heavy metal that is neither essential element nor has any role in the process of cell metabolism but it is easily absorbed and accumulated in different parts of a plant. The Pb uptake is mainly regulated by PH, particle size, and cation exchange capacity of the soil, root exudation and by different other physical and chemical parameters. The high concentration of Pb can cause a number of toxic symptoms in plants that may be retardation in growth (Stunted growth), negative affect on photosynthesis (chlorosis), blackening of roots and different other symptoms. Lead (Pb) has the ability to inhibit photosynthesis, disturb mineral nutrition and water balance, changes hormonal status and affects membrane structure and permeability. This review describes different morphological, physiological and biochemical effects of...
Identification of Chemical Forms of Lead in Soil and Fruits
The estimation of Pb in fruit and soil samples from Yelwa in Keffi Local Government Area of Nasarawa State, Nigeria was carried out. The objective of the study was to determine bioavailable Pbin these fruits and soil samples by flame atomic absorption spectrometry (FAAS) using sequential extraction technique. The concentrations of the metal in the fruit and soils vary from one sampling site to another. The soil samples related to the fruits where digested and extracted using different digestion and extraction reagents. The result revealed that the soil samples obtained from various locations contain varying amount of Pb and was distributed between residual, oxide, carbonate and exchangeable fractions. The result also showed that the concentration of Pb in the soil samples recorded was within the allowable limits of 200mg/kg and the ANOVA (p=0.000<0.05), showed that there is significant difference in the concentration of Pb in mango, orange, cashew and pawpaw Soils. Similarly, from the Duncan post hoc test, in the second homogenous subset, cashew soil has the highest concentration of Pb in their soils. On the other hand, in the second homogenous subset,mango, pawpaw and orange have less concentration of Pb in their soils.
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Un experimento en invernadero se estableció para determinar la concentración de plomo (Pb) en suelo, raíz y parte aérea de haba y avena; se calculó el factor de bioconcentración y traslocación en las dos especies. Se probaron 50, 100 y 150 mg•Pb•kg-1 de suelo, incluyendo un control. Las plantas se colectaron a los 60 días después de la siembra y se midieron altura de planta (AP), volumen radical (VR) y biomasa seca total (BST), además del contenido de Pb en suelo, raíz y parte aérea. La cuantificación de Pb se realizó por espectrofotometría de absorción atómica. El suelo cultivado con haba presentó un 28.48 % de Pb EDTA. Las variables AP, VR y BST no fueron afectadas de manera drástica por las concentraciones de Pb probadas. Las plantas de haba y avena absorbieron un total de 55 mg•kg-1 y 45.3 mg•kg-1 , respectivamente, las cuales se consideran tóxicas para plantas cultivadas. Los resultados pueden servir de base para ampliar el conocimiento del contenido de Pb absorbido y traslocado en plantas de haba y avena, ya que la capacidad de tolerar y absorber Pb es específica de la especie, inclusive de la variedad de planta.
Lead-Induced Changes in Fluorescence and Spectral Characteristics of Pea Leaves
Remote Sensing, 2019
Chlorophyll fluorescence parameters can provide useful indications of photosynthetic performance in vivo. Coupling appropriate fluorescence measurements with other noninvasive techniques, such as absorption spectroscopy or gas exchange, can provide insights into the limitations to photosynthesis under given conditions. Chlorophyll content is one of the dominant factors influencing the conditions of a vegetation growing season, and can be tested using both fluorescence and remote sensing methods. Hyperspectral remote sensing and recording the narrow range of the spectrum can be used to accurately analyze the parameters and properties of plants. The aim of this study was to analyze the influence of lead ions (Pb, 5 mM Pb(NO 3) 2) on the growth of pea plants using spectral properties. Hyperspectral remote sensing and chlorophyll fluorescence measurements were used to assess the physiological state of plants seedlings treated by lead ions during the experiment. The plants were growing in hydroponic cultures supplemented with Pb ions under various conditions (control, complete Knop + phosphorus (+P); complete Knop + phosphorus (+P) + Pb; Knop (-P) + Pb, distilled water + Pb) affecting lead uptake via the root system. Spectrometric measurements allowed us to calculate the remote sensing indices of vegetation, which were compared with chlorophyll and carotenoids content and fluorescence parameters. The lead contents in the leaves, roots, and stems were also analyzed. Spectral characteristics and vegetation properties were analyzed using statistical tests. We conclude that: (1) pea seedlings grown in complete Knop (with P) and in the presence of Pb ions were spectrally similar to the control plants because lead was not transported to the shoots of plants; (2) lead most influenced plants that were grown in water, according to the highest lead content in the leaves; and (3) the effects of lead on plant growth were confirmed by remote sensing indices, whereas fluorescence parameters identified physiological changes induced by Pb ions in the plants.
Sunflower Plants as Bioindicators of Environmental Pollution with Lead (II) Ions
Sensors, 2009
In this study, the influence of lead (II) ions on sunflower growth and biochemistry was investigated from various points of view. Sunflower plants were treated with 0, 10, 50, 100 and/or 500 µM Pb-EDTA for eight days. We observed alterations in growth in all experimental groups compared with non-treated control plants. Further we determined total content of proteins by a Bradford protein assay. By the eighth day of the experiment, total protein contents in all treated plants were much lower compared to control. Particularly noticeable was the loss of approx. 8 µg/mL or 15 µg/mL in shoots or roots of plants treated with 100 mM Pb-EDTA. We also focused our attention on the activity of alanine transaminase (ALT), aspartate transaminase (AST) and urease. Activity of the enzymes increased with increasing length of the treatment and applied concentration OPEN ACCESS GSSG/GSH ratio was about 0.66. In shoots, the oxidative stress was less distinctive, with a GSSG/GSH ratio 0.14. We also estimated the rate of phytochelatin biosynthesis from the slope of linear equations plotted with data measured in the particular experimental group. The highest rate was detected in roots treated with 100 µM of Pb-EDTA. To determine heavy metal ions many analytical instruments can be used, however, most of them are only able to quantify total content of the metals. This problem can be overcome using laser induced breakdown spectroscopy, because it is able to provide a high spatial-distribution of metal ions in different types of materials, including plant tissues. Data obtained were used to assemble 3D maps of Pb and Mg distribution. Distribution of these elements is concentrated around main vascular bundle of leaf, which means around midrib.