scholarly journals Modelling the Role of Active Biomass on the Fate and Transport of a Heavy Metal in the Presence of Root Exudates

1998 ◽  
Vol 1 (1) ◽  
Author(s):  
K. V. Nedunuri ◽  
L. E. Erickson ◽  
R. S. Govindaraju
Keyword(s):  
Heavy Metal ◽  
Root Exudates ◽  
Fate And Transport ◽  
Active Biomass

scholarly journals Remediation of Cd-Contaminated Soil by Modified Nanoscale Zero-Valent Iron: Role of Plant Root Exudates and Inner Mechanisms

2021 ◽  
Vol 18 (11) ◽  
pp. 5887
Author(s):  
Danlian Huang ◽  
Yunhe Yang ◽  
Rui Deng ◽  
Xiaomin Gong ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Root Exudates ◽  
Contaminated Soil ◽  
Great Influence ◽  
Zero Valent Iron ◽  
High Concentration ◽  
Soil Microbial Community Structure ◽  
Nanoscale Zero Valent Iron ◽  
Cd Removal

In this study, the role of exogenous root exudates and microorganisms was investigated in the application of modified nanoscale zero-valent iron (nZVI) for the remediation of cadmium (Cd)-contaminated soil. In this experiment, citric acid (CA) was used to simulate root exudates, which were then added to water and soil to simulate the pore water and rhizosphere environment. In detail, the experiment in water demonstrated that low concentration of CA facilitated Cd removal by nZVI, while the high concentration achieved the opposite. Among them, CA can promote the adsorption of Cd not only by direct complexation with heavy metal ions, but also by indirect effect to promote the production of iron hydroxyl oxides which has excellent heavy metal adsorption properties. Additionally, the H+ dissociated from CA posed a great influence on Cd removal. The situation in soil was similar to that in water, where low concentrations of CA contributed to the immobilization of Cd by nZVI, while high concentrations promoted the desorption of Cd and the generation of CA–Cd complexes which facilitated the uptake of Cd by plants. As the reaction progressed, the soil pH and cation exchange capacity (CEC) increased, while organic matter (OM) decreased. Meanwhile, the soil microbial community structure and diversity were investigated by high-throughput sequencing after incubation with CA and nZVI. It was found that a high concentration of CA was not conducive to the growth of microorganisms, while CMC had the effect of alleviating the biological toxicity of nZVI.

scholarly journals Dzyaloshinskii–Moriya interaction in noncentrosymmetric superlattices

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Woo Seung Ham ◽  
Abdul-Muizz Pradipto ◽  
Kay Yakushiji ◽  
Kwangsu Kim ◽  
Sonny H. Rhim ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Degrees Of Freedom ◽  
Orbit Coupling ◽  
Inversion Symmetry ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Band Formation ◽  
Research Activities ◽  
Moriya Interaction

AbstractDzyaloshinskii–Moriya interaction (DMI) is considered as one of the most important energies for specific chiral textures such as magnetic skyrmions. The keys of generating DMI are the absence of structural inversion symmetry and exchange energy with spin–orbit coupling. Therefore, a vast majority of research activities about DMI are mainly limited to heavy metal/ferromagnet bilayer systems, only focusing on their interfaces. Here, we report an asymmetric band formation in a superlattices (SL) which arises from inversion symmetry breaking in stacking order of atomic layers, implying the role of bulk-like contribution. Such bulk DMI is more than 300% larger than simple sum of interfacial contribution. Moreover, the asymmetric band is largely affected by strong spin–orbit coupling, showing crucial role of a heavy metal even in the non-interfacial origin of DMI. Our work provides more degrees of freedom to design chiral magnets for spintronics applications.

scholarly journals The Role of Aquaporin Overexpression in the Modulation of Transcription of Heavy Metal Transporters under Cadmium Treatment in Poplar

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Andrea Neri ◽  
Silvia Traversari ◽  
Andrea Andreucci ◽  
Alessandra Francini ◽  
Luca Sebastiani
Keyword(s):  
Heavy Metal ◽  
Transcriptional Response ◽  
Metal Transporters ◽  
Metal Transporter ◽  
Cadmium Treatment ◽  
Tolerance To Cadmium ◽  
Different Response ◽  
Cd Translocation ◽  
Hydroponic Conditions

Populus alba ‘Villafranca’ clone is well-known for its tolerance to cadmium (Cd). To determine the mechanisms of Cd tolerance of this species, wild-type (wt) plants were compared with transgenic plants over-expressing an aquaporin (aqua1, GenBank GQ918138). Plants were maintained in hydroponic conditions with Hoagland’s solution and treated with 10 µM of Cd, renewed every 5 d. The transcription levels of heavy metal transporter genes (PaHMA2, PaNRAMP1.3, PaNRAMP2, PaNRAMP3.1, PaNRAMP3.2, PaABCC9, and PaABCC13) were analyzed at 1, 7, and 60 d of treatment. Cd application did not induce visible toxicity symptoms in wt and aqua1 plants even after 2 months of treatment confirming the high tolerance of this poplar species to Cd. Most of the analyzed genes showed in wt plants a quick response in transcription at 1 d of treatment and an adaptation at 60 d. On the contrary, a lower transcriptional response was observed in aqua1 plants in concomitance with a higher Cd concentration in medial leaves. Moreover, PaHMA2 showed at 1 d an opposite trend within organs since it was up-regulated in root and stem of wt plants and in leaves of aqua1 plants. In summary, aqua1 overexpression in poplar improved Cd translocation suggesting a lower Cd sensitivity of aqua1 plants. This different response might be due to a different transcription of PaNRAMP3 genes that were more transcribed in wt line because of the importance of this gene in Cd compartmentalization.

Geochemical modeling and multivariate statistical approach for assessing the groundwater quality, and mechanism of arsenic mobilization in Bahraich region, Indo-Gangetic plains, India

2021 ◽  
Author(s):  
Mohd Usman Khan ◽  
Nachiketa Rai ◽  
Mukesh Kumar Sharma
Keyword(s):  
Heavy Metal ◽  
Drinking Water ◽  
Heavy Metal Contamination ◽  
Geochemical Modeling ◽  
Sulfide Oxidation ◽  
Dissolution Mechanism ◽  
Multivariate Statistical ◽  
Gangetic Plains ◽  
Groundwater Samples

<p>As contamination in groundwater has been reported from various regions of the Indian subcontinent but no data related to heavy metal contamination of groundwater has been reported for the Bahraich area in the Indo-Gangetic plains. We report the first dataset on arsenic contamination and groundwater hydrogeochemistry, in Bahraich. This includes concentrations of heavy metal such as As, Mn, and Fe, along with major cations (Na<sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>and Mg<sup>2+</sup>) and anions (F<sup>-</sup>, Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup> and PO<sub>4</sub><sup>3-</sup>), and dissolved organic carbon (DOC), along with various physico-chemical parameters such as EC, pH, and Eh from samples collected during two extensive field campaigns conducted during pre-monsoon, and post-monsoon seasons respectively. The combined use of geochemical modeling and multivariate statistical approaches such as principal component analysis (PCA) and correlation analysis (CA) suggest several processes affecting the geochemistry of groundwater including the lithological characteristics of aquifers and anthropogenic activities.</p><p>The groundwater of the study area predominantly belongs to the Ca-Mg-HCO<sub>3</sub> type hydrochemical facies. HCO<sub>3</sub><sup>−</sup>/Na<sup>+</sup> and Ca<sup>2+</sup>/Na<sup>+</sup> signatures of groundwater indicate the influence of silicate weathering and carbonate dissolution processes with the insignificant role of evaporate dissolution mechanism. As concentration was found to range from 0.6 μg/L to ~100 μg/L with almost 40% of the collected samples exceeding the WHO defined limit of 10 μg/L for drinking water. 70 % of the groundwater samples were found to have very high Fe concentrations exceeding the WHO guideline of 0.3 mg/l in drinking water. Mn concentrations in the groundwater samples were relatively low with only ~10 % of the samples exceeding the WHO defined limit for Mn (400 μg/L). The majority of the groundwater samples were found to be anoxic in nature showing low NO<sub>3</sub><sup>−</sup> & SO<sub>4</sub><sup>2-</sup> concentrations, high Fe & Mn and DOC concentrations, and negative Eh values.</p><p>Results from this study show that the reductive dissolution mechanism of iron oxyhydroxide is the dominant mechanism responsible for arsenic release in groundwater of the region, ruling out any role of sulfide oxidation and alkali desorption.</p><p> </p><p> </p>

scholarly journals Complex interactions in legume/cereal intercropping system: role of root exudates in root-to-root communication

2017 ◽  
Author(s):  
Yinshan Jiao ◽  
Entao Wang ◽  
Wenfeng Chen ◽  
Donald L. Smith
Keyword(s):  
Nitrogen Fixation ◽  
Root Exudates ◽  
Faba Bean ◽  
The Novel ◽  
Practical Application ◽  
Corn Root ◽  
Complex Interactions ◽  
Root Interactions ◽  
Ecological Principles

Dear Editor,Legume/cereal intercropping systems have been regarded as the practical application of basic ecological principles such as diversity, competition and facilitation. In a recent PNAS paper, Li et al. (1) describe the novel finding that maize exudates promote faba bean nodulation and nitrogen fixation by upregulating genes involved in (iso)flavonoids synthesis (chalcone–flavanone isomerase) within faba bean, resulting in production of more genistein, a legume-to-rhizobia signal during establishment of the faba bean N2–fixing symbiosis. Although we salute the authors’ methodological efforts, there is another mechanism that could be responsible for the effect of corn root exudates on faba been nitrogen fixation observed in this article (1). The authors may misunderstand their data and the signalling role of maize exudates, thus got a defective model for the root interactions between faba bean and maize.

scholarly journals Protective Role of Agrimonia eupatoria L. in Heavy Metal Induced Nephrotoxicity

2018 ◽  
Vol 62 (2) ◽  
pp. 13-18
Author(s):  
D. Marcinčáková ◽  
M. Falis ◽  
P. Schusterová ◽  
P. Váczi ◽  
S. Marcinčák ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Potassium Dichromate ◽  
Ethanolic Extract ◽  
Protective Role ◽  
Rabbit Kidney ◽  
Cell Adherence ◽  
Metal Compounds ◽  
Sulfate Heptahydrate ◽  
Chloride Dihydrate

Abstract The aim of this study was to evaluate the potential protective role of Agrimonia eupatoria L. in heavy metal induced nephrotoxicity. Rabbit kidney epithelial cells (RK13) were used as the model cell line. They were exposed to three different heavy metal compounds: cadmium chloride dihydrate CdCl2.2H2O (15 and 20 mg.l−1), potassium dichromate K2Cr2O7 (1, 10 mg.l−1), and zinc sulfate heptahydrate ZnSO4.7H2O (50, 150 mg.l−1) simultaneously with agrimony (ethanolic extract, 100 mg.l−1). The cell response was recorded using the xCELLigence system or real-time cell analysis (RTCA) as a cell index (CI) and expressed as cell adherence (%) compared to control cells without treatment. The potential nephroprotective effects were recorded in cells treated with chromium (1 a 10 mg.l−1) and agrimony, where the cell adherence increased from 95.11 ± 11.25 % and 7.24 ± 0.33 % to 103.26 ± 1.23 % and 68.54 ± 4.89 % (P < 0.05) respectfully and also with a combination of agrimony and zinc (150 mg.l−1), where the adherence increased from 57.45 ± 1.98 % to 95.4 ± 6.95 %. During the cell exposure to cadmium in combination with agrimony, the protective effect was not recorded; the adherence of cells was even decreased (P < 0.05).

scholarly journals Organic compounds in root exudates of Miscanthus × Giganteus greef et deu and limitation of microorganisms in its rhizosphere by nutrients

2010 ◽  
Vol 58 (5) ◽  
pp. 203-208 ◽  
Author(s):  
Hana Kaňová ◽  
Joffrey Carre ◽  
Valerie Vranová ◽  
Klement Rejšek ◽  
Pavel Formánek
Keyword(s):  
Organic Acids ◽  
Organic Compounds ◽  
Respiration Rate ◽  
Root Exudates ◽  
Plant Nutrients ◽  
Rhizospheric Soil ◽  
Polluted Soils ◽  
Rhizosphere Microorganisms ◽  
Miscanthus Giganteus

This study was conducted to determine the composition of sugars and organic acids in root exudates of Miscanthus × Giganteus and to find out if microorganisms of the rhizospheric soil are limited by mi­ne­ral nutrients. The following sugars and organic acids were determined in root exudates of this plant: glucose, saccharose, and acids such as succinic, propionic, citric, tartaric, malic, oxalic, ascorbic, acetic and fumaric. Respiration of soil from rhizosphere of Miscanthus × Giganteus was found to be limited by N, K and Ca. Respiration rate after application of mineral compounds increased in following orther: nitrate > calcium > potassium > ammonium, giving approx. 165, 99, 52 and 31 % increase compared to control. Further research is necessary to determine the role of plant nutrients from the point of their limitations for rhizosphere microorganisms, to broader very rare knowledges in this topic, especially for polluted soils to stimulate efficiency of phytoremediations.

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