scholarly journals Strigolactones Modulate Cellular Antioxidant Defense Mechanisms to Mitigate Arsenate Toxicity in Rice Shoots

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1815
Author(s):  
Mohammad Golam Mostofa ◽  
Chien Van Ha ◽  
Md. Mezanur Rahman ◽  
Kien Huu Nguyen ◽  
Sanjida Sultana Keya ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Membrane Damage ◽  
Mass Spectrometry Analysis ◽  
Rice Varieties ◽  
Spectrometry Analysis ◽  
Arsenate Stress ◽  
Arsenic Stress ◽  
Antioxidant Defense Systems

Metalloid contamination, such as arsenic poisoning, poses a significant environmental problem, reducing plant productivity and putting human health at risk. Phytohormones are known to regulate arsenic stress; however, the function of strigolactones (SLs) in arsenic stress tolerance in rice is rarely investigated. Here, we investigated shoot responses of wild-type (WT) and SL-deficient d10 and d17 rice mutants under arsenate stress to elucidate SLs’ roles in rice adaptation to arsenic. Under arsenate stress, the d10 and d17 mutants displayed severe growth abnormalities, including phenotypic aberrations, chlorosis and biomass loss, relative to WT. Arsenate stress activated the SL-biosynthetic pathway by enhancing the expression of SL-biosynthetic genes D10 and D17 in WT shoots. No differences in arsenic levels between WT and SL-biosynthetic mutants were found from Inductively Coupled Plasma-Mass Spectrometry analysis, demonstrating that the greater growth defects of mutant plants did not result from accumulated arsenic in shoots. The d10 and d17 plants had higher levels of reactive oxygen species, water loss, electrolyte leakage and membrane damage but lower activities of superoxide dismutase, ascorbate peroxidase, glutathione peroxidase and glutathione S-transferase than did the WT, implying that arsenate caused substantial oxidative stress in the SL mutants. Furthermore, WT plants had higher glutathione (GSH) contents and transcript levels of OsGSH1, OsGSH2, OsPCS1 and OsABCC1 in their shoots, indicating an upregulation of GSH-assisted arsenic sequestration into vacuoles. We conclude that arsenate stress activated SL biosynthesis, which led to enhanced arsenate tolerance through the stimulation of cellular antioxidant defense systems and vacuolar sequestration of arsenic, suggesting a novel role for SLs in rice adaptation to arsenic stress. Our findings have significant implications in the development of arsenic-resistant rice varieties for safe and sustainable rice production in arsenic-polluted soils.

The Occurrence and Origin of Pentlandite-Chalcopyrite-Pyrrhotite Loop Textures in Magmatic Ni-Cu Sulfide Ores

2020 ◽  
Vol 115 (8) ◽  
pp. 1777-1798 ◽  
Author(s):  
Stephen J. Barnes ◽  
Valentina Taranovic ◽  
Louise E. Schoneveld ◽  
Eduardo T. Mansur ◽  
Margaux Le Vaillant ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Peritectic Reaction ◽  
Inductively Coupled Plasma ◽  
Mass Spectrometry Analysis ◽  
Sulfide Liquid ◽  
Monosulfide Solid Solution ◽  
Spectrometry Analysis ◽  
Inductively Coupled ◽  
Regional Deformation ◽  
Wide Range

Abstract Pentlandite is the dominant Ni-hosting ore mineral in most magmatic sulfide deposits and has conventionally been interpreted as being entirely generated by solid-state exsolution from the high-temperature monosulfide solid solution (MSS) (Fe,Ni)1–xS. This process gives rise to the development of loops of pentlandite surrounding pyrrhotite grains. Recently it has been recognized that not all pentlandite forms by exsolution. Some may form as the result of peritectic reaction between early formed MSS and residual Ni-Cu–rich sulfide liquid during differentiation of the sulfide melt, such that at least some loop textures may be genuinely magmatic in origin. Testing this hypothesis involved microbeam X-ray fluorescence mapping to image pentlandite-pyrrhotite-chalcopyrite intergrowths from a range of different deposits. These deposits exemplify slowly cooled magmatic environments (Nova, Western Australia; Sudbury, Canada), globular ores from shallow-level intrusions (Norilsk, Siberia), extrusive komatiite-hosted ores from low and high metamorphic-grade terranes, and a number of other deposits. Our approach was complemented by laser ablation-inductively coupled plasma-mass spectrometry analysis of palladium in varying textural types of pentlandite within these deposits. Pentlandite forming coarse granular aggregates, together with loop-textured pentlandite where chalcopyrite also forms part of the loop framework, consistently has the highest Pd content compared with pentlandite clearly exsolved as lamellae from MSS or pyrrhotite. This is consistent with much of granular and loop pentlandite being formed by peritectic reaction between Pd-rich residual sulfide liquid and early crystallized MSS, rather than forming entirely by subsolidus grain boundary exsolution from MSS, as has hitherto been assumed. The wide range of Pd contents in pentlandite in individual samples reflects a continuum of processes between peritectic reaction and grain boundary exsolution. Textures in metamorphically recrystallized ores are distinctly different from loop-textured ores, implying that loop textures cannot be regenerated (except in special circumstances) by metamorphic recrystallization of original magmatic-textured ores. The presence of loop textures can therefore be taken as evidence of a lack of penetrative deformation and remobilization at submagmatic temperatures, a conclusion of particular significance to the interpretation of the Nova deposit as having formed synchronously with the peak of regional deformation at temperatures within the sulfide melting range.

Evaluation of Trace Elements in Potatoes (Solanum tuberosum) from a Suburban Area of Naples, Italy: The “Triangle of Death”

2017 ◽  
Vol 80 (7) ◽  
pp. 1167-1171 ◽  
Author(s):  
Antonella De Roma ◽  
Maria Cesarina Abete ◽  
Paola Brizio ◽  
Giuseppe Picazio ◽  
Marcello Caiazzo ◽  
...  
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Climatic Factors ◽  
Suburban Area ◽  
Mass Spectrometry Analysis ◽  
World Health ◽  
Health Concern ◽  
Campania Region ◽  
Spectrometry Analysis ◽  
Health Organization

ABSTRACT Human exposure to contaminated food is a general health concern worldwide; it is necessary to evaluate food safety with respect to contaminants present in the edible parts of major food crops. This study evaluated the concentrations of 17 trace elements (As, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Sn, Tl, V, and Zn) from 51 potato plantations in the Campania region, inside the area known as the “Triangle of Death,” with inductively coupled plasma mass spectrometry analysis. Results confirm that the potatoes collected from the suburban area of Naples contained concentrations of trace elements below the safe limits prescribed by the Food and Agriculture Organization of the United Nations and the World Health Organization. The concentrations of elements were similar to those reported for potatoes grown in other countries. Monitoring the content of toxic and potentially toxic elements is one of the most important aspects of food quality assurance. The environmental persistence of metals may result in the accumulation of significant levels of these contaminants in plants. They are absorbed to different extents, depending on their source, soil and climatic factors, plant genotype, and agrotechnical conditions, thereby entering the food chain and representing a risk to human health.

Genes for Mn(II)-dependent NahC and Fe(II)-dependent NahH located in close proximity in the thermophilic naphthalene and PCB degrader, Bacillus sp. JF8: cloning and characterization

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 993-1004 ◽  
Author(s):  
Daisuke Miyazawa ◽  
Gouri Mukerjee-Dhar ◽  
Minoru Shimura ◽  
Takashi Hatta ◽  
Kazuhide Kimbara
Keyword(s):  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Polychlorinated Biphenyl ◽  
Mass Spectrometry Analysis ◽  
Northern Hybridization ◽  
Active Site Residues ◽  
Extradiol Dioxygenase ◽  
Spectrometry Analysis ◽  
Dna Fragment ◽  
Extradiol Dioxygenases

A 10 kb DNA fragment was isolated using a DNA probe derived from the N-terminal amino acid sequence of the extradiol dioxygenase purified from naphthalene-grown Bacillus sp. JF8, a thermophilic naphthalene and polychlorinated biphenyl degrader. The cloned DNA fragment had six open reading frames, designated nahHLOMmocBnahC based on sequence homology, of which the products NahH_JF8 and NahC_JF8 were extradiol dioxygenases. Although NahC_JF8 and NahH_JF8 exhibit low homology to known extradiol dioxygenases, the active-site residues and metal ion ligands are conserved. The presence of Mn(II) in culture medium was found to be essential for production of active recombinant NahC_JF8, while Fe(II) was necessary for active recombinant NahH_JF8. Inductively coupled plasma mass spectrometry analysis of active NahC_JF8 identified the cofactor to be manganese, indicating a Mn(II)-dependent extradiol dioxygenase. NahC_JF8 exhibited K m values of 32±5 μM for 1,2-dihydroxynaphthalene and 510±90 μM for 2,3-dihydroxybiphenyl at 60 °C. In cell-free extracts, NahH_JF8 exhibited a broad substrate range for 2,3-dihydroxybiphenyl, catechol, and 3- and 4-methylcatechol at 25 °C. Stability studies on the Mn(II)-dependent NahC_JF8 indicated that it was thermostable, retaining 50 % activity after incubation at 80 °C for 20 min, and it exhibited resistance to EDTA and H2O2. Northern hybridization studies clarified that both NahC_JF8 and NahH_JF8 were induced by naphthalene; RT-PCR showed that nahHLOMmocBnahC is expressed as a single transcript.

scholarly journals Gallium and germanium geochemistry during magmatic fractionation and post-magmatic alteration in different types of granitoids: a case study from the Bohemian Massif (Czech Republic)

2013 ◽  
Vol 64 (3) ◽  
pp. 171-180b ◽  
Author(s):  
Karel Breiter ◽  
Nina Gardenová ◽  
Viktor Kanický ◽  
Tomáš Vaculovič
Keyword(s):  
Bohemian Massif ◽  
Inductively Coupled Plasma ◽  
Mass Spectrometry Analysis ◽  
Elemental Ratios ◽  
Spectrometry Analysis ◽  
Inductively Coupled ◽  
Different Types ◽  
Plasma Mass Spectrometry ◽  
Highly Evolved

Abstract Contents of Ga and Ge in granites, rhyolites, orthogneisses and greisens of different geochemical types from the Bohemian Massif were studied using inductively coupled plasma mass spectrometry analysis of typical whole-rock samples. The contents of both elements generally increase during fractionation of granitic melts: Ga from 16 to 77 ppm and Ge from 1 to 5 ppm. The differences in Ge and Ga contents between strongly peraluminous (S-type) and slightly peraluminous (A-type) granites were negligible. The elemental ratios of Si/1000Ge and Al/1000Ga significantly decreased during magmatic fraction: from ca. 320 to 62 and from 4.6 to 1.2, respectively. During greisenization, Ge is enriched and hosted in newly formed hydrothermal topaz, while Ga is dispersed into fluid. The graph Al/Ga vs. Y/Ho seems to be useful tool for geochemical interpretation of highly evolved granitoids.

Antioxidant defense mechanisms of endothelial cells: glutathione redox cycle versus catalase

1986 ◽  
Vol 251 (5) ◽  
pp. C671-C680 ◽  
Author(s):  
N. Suttorp ◽  
W. Toepfer ◽  
L. Roka
Keyword(s):  
Endothelial Cells ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Buthionine Sulfoximine ◽  
Alpha Tocopherol ◽  
Target Cells ◽  
Redox Cycle ◽  
Extracellular Flux ◽  
Glutathione Redox Cycle ◽  
Antioxidant Defense Systems

The importance of the glutathione (GSH) redox cycle and of catalase as intracellular antioxidant defense systems in cultured endothelial cells against an extracellular flux of H2O2, a critical mediator of polymorphonuclear leukocyte-induced oxidant injury of endothelial cells, was examined. The activities of different parts of the GSH redox cycle were impaired by 1,3-bis(2-chloroethyl)-1-nitrosourea, buthionine sulfoximine, diethyl maleate and 2-cyclohexene-1-one. Catalase activity was inhibited by 3-amino-1,2,4-triazole. After an impairment of the GSH redox cycle, but not of catalase, the susceptibility of pulmonary artery endothelial cells to an attack by H2O2 was dramatically increased independent of the source of extracellularly generated hydrogen peroxide (i.e., glucose oxidase or stimulated polymorphonuclear leukocytes). Exogenous catalase, d-alpha-tocopherol, and particularly Trolox, the chroman compound of tocopherol, but not phytol, the fatty acid side chain of tocopherol, provided almost complete protection of the endothelial cells against a H2O2-mediated attack. Additional fluorometric studies suggested that H2O2 is scavenged by the antioxidants before it hits the target cells.

scholarly journals Gadolinite-(Nd), a new member of the gadolinite supergroup from Fe-REE deposits of Bastnäs-type, Sweden

2018 ◽  
Vol 82 (S1) ◽  
pp. S133-S145 ◽  
Author(s):  
Radek Škoda ◽  
Jakub Plášil ◽  
Renata Čopjaková ◽  
Milan Novák ◽  
Erik Jonsson ◽  
...  
Keyword(s):  
Rare Earth ◽  
Inductively Coupled Plasma ◽  
Mass Spectrometry Analysis ◽  
Vibration Band ◽  
Calculated Density ◽  
Spectrometry Analysis ◽  
Conchoidal Fracture ◽  
South Central ◽  
Heavy Rare Earth Elements ◽  
Olive Green

ABSTRACTA new member of the gadolinite supergroup, gadolinite-(Nd), IMA2016-013, ideally Nd2FeBe2Si2O10, was found in the Malmkärra mine, ~3.5 km WSW of Norberg, south-central Sweden, where it occurs in association with fluorbritholite-(Ce), västmanlandite-(Ce), dollaseite-(Ce), bastnäsite-(Ce) and tremolite. Gadolinite-(Nd) forms anhedral grains up to 150 µm in size, commonly occurring as aggregates of olive green colour. The crystals are transparent with vitreous to adamantine lustre. Gadolinite-(Nd) is brittle with conchoidal fracture, no cleavage or parting was observed. It has a white streak, the Mohs hardness is 6.5–7 and the calculated density is 4.86 g cm–3. Optically, the mineral is weakly pleochroic in shades of olive green, biaxial (–), nα = 1.78(1), nβ(calc.) = 1.80, nγ = 1.81(1) measured in white light, 2V(meas.) = 62(3)°. Electron-microprobe and laser ablation inductively coupled plasma mass spectrometry analysis [in wt.%] provided SiO2 21.77, Y2O3 5.49, La2O3 2.78, Ce2 O3 14.04, Pr2O3 3.28, Nd2O3 19.27, Sm2O3 5.30, Eu2O3 0.24, Gd2O3 4.10, Tb2O3 0.36, Dy2O3 1.32, Ho2O3 0.18, Er2O3 0.38, MgO 0.51, CaO 0.14, MnO 0.10, FeO 10.62, B2O3 0.10, BeOcalc. 8.99, H2Ocalc. 0.55 and total 99.52 giving the following empirical formula (based on 2 Si): (Nd0.632 Ce0.472Y0.268Sm0.168Gd0.125Pr0.110La0.094Dy0.039Ca0.014Er0.011Tb0.011Eu0.008Ho0.008)∑1.957(Fe0.816Mg0.070Mn0.008)∑0.894(Be1.984B0.016)∑2.000Si2O9.660OH0.337. A weak Raman vibration band at ~3525 cm–1 confirms the presence of water in the structure. Gadolinite-(Nd) is monoclinic, P21/c, with a = 4.8216(3) Å, b = 7.6985(4) Å, c = 10.1362(6) Å, β = 90.234(4)°, V = 376.24(6) Å3 and Z = 2. The strongest X-ray diffraction lines are [dobs in Å (hkl) Irel]: 4.830 (100) 72, 3.603 (021) 37, 3.191(-112) 52, 3.097 (013) 35, 2.888 (121) 100, 2.607(113) 49, 2.412 (200) 24. Along with the Malmkärra mine, gadolinite-(Nd) was also recorded also at Johannagruvan and Nya Bastnäs. The minerals of the gadolinite subgroup together with fluorbritholite-(Ce) incorporate the highest fraction of medium-to-heavy rare-earth elements among associated rare-earth element minerals in the Malmkärra mine and possibly in all Bastnäs-type deposits.

scholarly journals Assessment of Pb(II), Cd(II) and Al(III) Removal Capacity of Bacteria From Food and Gut Ecological Niches: Insights Into Biodiversity to Limit Intestinal Biodisponibility of Toxic Metals

2021 ◽  
Author(s):  
Fanny George ◽  
Séverine Mahieux ◽  
Catherine Daniel ◽  
Marie Titécat ◽  
Nicolas Beauval ◽  
...  
Keyword(s):  
Toxic Metals ◽  
Inductively Coupled Plasma ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Mass Spectrometry Analysis ◽  
Ecological Niches ◽  
Spectrometry Analysis ◽  
Lead And Cadmium ◽  
Removal Capacity

Hazardous toxic metals, such as lead and cadmium, and to a lesser extent aluminum, are extensively recognized as detrimental for health following ingestion within food and water, or following inhalation. Gut and food-derived microbes, by interacting with heavy metals, may actively or passively modulate their bioavailability inside the gut, either by adsorption or by sequestration. Such a bioremediation within the gut implies the selection of safe microbes, based on their specific capacities to immobilize metals. We investigated the metal removal ability of 225 bacteria toward the potential harmful trace elements lead, cadmium and aluminum in vitro, using Inductively Coupled Plasma Mass Spectrometry analysis. Interspecies and intraspecies comparisons were addressed and discussed among bacteria from the phylum Firmicutes, which are mostly lactic acid bacteria, including Lactobacillus spp, with some Lactococcus, Pediococcus and Carnobacterium representatives, Actinobacteria as well as Proteobacteria. The effect on mixture of lead and cadmium was also investigated. Although the purpose of such a screening is so far not to elucidate each of the various strain specific- and metal dependent- mechanisms of heavy metal removal, we identified potential bacteria which are able to alleviate Pb(II) and Cd(II) concerns in order to propose performing candidate probiotics for metal xenobiotic bioremediation.

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