The evaluation of cadmium, zinc and nickel accumulation ability of transgenic tobacco bearing different transgenes

Tobacco, Nicotiana tabacum L., var. Wisconsin 38 as the control (WSC), and four genetically modified lines of the same variety, were tested for Cd, Zn and Ni accumulation. Genetically modified lines of the same variety, bearing the transgene CUP1 (gene coding a yeast metallothionein), GUS (reporter gene for ß-glucuronidase), HisCUP (CUP combined with a polyhistidine tail), and HisGUS (reporter gene for ß-glucuronidase, combined with a polyhistidine tail) under a constitutive promoter, enabling it to follow the heavy metal tolerance and uptake changes as a function of the transgene present. Control and transgenic lines were tested for accumulation of risk elements on sand nutrient medium with the addition of cadmium, zinc and nickel. The results showed high Cd accumulation ability of HisCUP line. The Cd content in aboveground biomass was increased by 90% compared to the non-transformed control and Cd content in roots was decreased by 49%. Determination of Zn content in aboveground biomass did not confirm higher uptake by transgenic plants significant for phytoremediation. The Ni content was significantly increased in aboveground biomass of HisGUS construct. GUS construct introduced the ability to accumulate all investigated metals; the others accumulated only one in extended amount.

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(288) An Arabidopsis thaliana Phytochelatin Synthase (AtPCS1) Gene Expressed in Transgenic Indian Mustard Contributes Partial Tolerance to Cd and Zn

HortScience ◽

10.21273/hortsci.40.4.1080e ◽

2005 ◽

Vol 40 (4) ◽

pp. 1080E-1081

Author(s):

Ksenija Gasic ◽

Schuyler S. Korban

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Arabidopsis Thaliana ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Indian Mustard ◽

35S Promoter ◽

Phytochelatin Synthase ◽

Mrna Accumulation ◽

Transgenic Lines

Phytochelatins (PCs) are heavy metal binding peptides that play important roles in sequestration and detoxification of heavy metals in plants. To develop transgenic plants with increased tolerance and/or accumulation of heavy metals from soil, an Arabidopsis thaliana FLAG–tagged AtPCS1 cDNA encoding phytochelatin synthase (PCS) under the control of a 35S promoter was expressed in Indian mustard (Brassica juncea). Four transgenic Indian mustard lines, designated pc lines, with different levels of AtPCS1 mRNA accumulation and correspondent AtPCS1 protein levels were selected and analyzed for tolerance to cadmium (Cd) and zinc (Zn). Heavy metal tolerance was assessed by measuring root length of 10-day-old seedlings grown on agar medium supplemented with different concentrations of Cd (0, 100, 150, and 200 μm CdCl2) and Zn (200, 400, 600, and 800 μm ZnCl2). All transgenic lines showed significantly longer roots when grown on a medium supplemented with 100 μm CdCl2. No significant differences were observed between transgenic lines and wild type when plants were grown on higher levels of Cd. This indicated that only partial tolerance to Cd was observed in these transgenic lines. Similarly, partial tolerance for Zn was also observed in these transgenic lines, but up to levels of 400 μm ZnCl2. Expression levels of AtPCS1 protein were not related to tolerance responses for either Cd or Zn stresses in transgenic lines.

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Field performance and heavy metal concentrations of transgenic flue-cured tobacco expressing a mammalian metallothionein-β-glucuronidase gene fusion

Genome ◽

10.1139/g93-035 ◽

1993 ◽

Vol 36 (2) ◽

pp. 255-260 ◽

Cited By ~ 18

Author(s):

J. E. Brandle ◽

H. Labbe ◽

J. Hattori ◽

B. L. Miki

Keyword(s):

Heavy Metal ◽

Gene Fusion ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Leaf Tissue ◽

Cauliflower Mosaic Virus ◽

35S Promoter ◽

Specific Expression ◽

High Background ◽

Transgenic Lines

Cadmium (Cd) is a nonessential heavy metal that can cause acute and chronic illness in humans. Some plant species such as tobacco (Nicotiana tabacum L.) tend to accumulate high levels of Cd in leaf tissue, the consumed portion of the plant. Tissue-specific expression of mammalian metallothionein has been suggested as a means of partitioning Cd in nonconsumed portions of transgenic plants. The purpose of the experiment reported here was to evaluate Cd concentration and agronomic performance of four field-grown transgenic tobacco lines harbouring a metallothionein-β-glucuronidase (MG) gene fusion driven by the constitutive 35S promoter of cauliflower mosaic virus. The trial was grown in a region of Canada known to have high background levels of Cd. The agronomic evaluation showed that some of the transgenic lines were equal to, while others performed more poorly than, the untransformed control for yield, days to flower, and leaf number. Gene expression measured by β-glucuronidase activity showed that all of the transgenic lines expressed the MG gene in the upper portion of the plant. One line did not express the MG gene in the roots. Cd levels in the leaf tissue of transformed lines were not significantly different from the untransformed control.Key words: cadmium, β-glucuronidase, transformation, heavy metal tolerance.

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Heavy metal tolerance and accumulation of Triarrhena sacchariflora, a large amphibious ornamental grass

Water Science & Technology ◽

10.2166/wst.2013.424 ◽

2013 ◽

Vol 68 (8) ◽

pp. 1795-1800 ◽

Cited By ~ 5

Author(s):

R. N. Tian ◽

S. Yu ◽

S. G. Wang ◽

Y. Zhang ◽

J. Y. Tang ◽

...

Keyword(s):

Heavy Metal ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Dry Weight ◽

Cd Stress ◽

Bioconcentration Factors ◽

Uptake Efficiency ◽

Translocation Efficiency ◽

Hyperaccumulator Plant ◽

Accumulation Ability

In this study, we report the tolerance and accumulation of Triarrhena sacchariflora to copper (Cu) and cadmium (Cd). The results show that T. sacchariflora had strong tolerance to Cu and Cd stress. The tolerance indexes (TI) were greater than 0.5 for all treatments. The bioconcentration factors (BCFs) to Cu and Cd were both above 1.0. The accumulation ability of roots was stronger than that of shoots, and ranges of BCF to Cu and Cd in roots were 37.89–79.08 and 83.96–300.57, respectively. However, the translocation ability to Cu and Cd was weak, with more than 86% of Cu or Cd accumulated in roots, suggesting an exclusion strategy for heavy metal tolerance. The uptake efficiency (UE) and translocation efficiency (TE) to Cu and Cd increased linearly as the Cu and Cd concentration in the substrate increased. UE was higher than TE, with a maximum of 2,118.90 μg g−1 root dry weight (DW) (50 mg L−1 Cu) and 1,847.51 μg g−1 root DW (20 mg L−1Cd), respectively. The results indicate that T. sacchariflora is a Cu- and Cd-tolerant non-hyperaccumulator plant, suggesting that T. sacchariflora could play an important role in phytoremediation in areas contaminated with Cu and Cd.

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Presence In the Intestinal Lumen of Marine Fish of Corpuscles with a High Cadmium-, Zinc- and Copper-Binding Capacity: A Possible Mechanism of Heavy Metal Tolerance

Marine Ecology Progress Series ◽

10.3354/meps004175 ◽

1981 ◽

Vol 4 ◽

pp. 175-181 ◽

Cited By ~ 16

Author(s):

F Noel-Lambot

Keyword(s):

Heavy Metal ◽

Marine Fish ◽

Metal Tolerance ◽

Binding Capacity ◽

Heavy Metal Tolerance ◽

Intestinal Lumen ◽

Copper Binding ◽

Cadmium Zinc

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Heavy Metal Tolerance Trend in Extended-Spectrum β-Lactamase Encoding Strains Recovered from Food Samples

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094718 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4718

Author(s):

Kashaf Junaid ◽

Hasan Ejaz ◽

Iram Asim ◽

Sonia Younas ◽

Humaira Yasmeen ◽

...

Keyword(s):

Heavy Metal ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Heavy Metal Resistance ◽

Metal Resistance ◽

Food Samples ◽

Esbl Production ◽

Extended Spectrum ◽

Retail Food ◽

Esbl Producers

This study evaluates bacteriological profiles in ready-to-eat (RTE) foods and assesses antibiotic resistance, extended-spectrum β-lactamase (ESBL) production by gram-negative bacteria, and heavy metal tolerance. In total, 436 retail food samples were collected and cultured. The isolates were screened for ESBL production and molecular detection of ESBL-encoding genes. Furthermore, all isolates were evaluated for heavy metal tolerance. From 352 culture-positive samples, 406 g-negative bacteria were identified. Raw food samples were more often contaminated than refined food (84.71% vs. 76.32%). The predominant isolates were Klebsiella pneumoniae (n = 76), Enterobacter cloacae (n = 58), and Escherichia coli (n = 56). Overall, the percentage of ESBL producers was higher in raw food samples, although higher occurrences of ESBL-producing E. coli (p = 0.01) and Pseudomonas aeruginosa (p = 0.02) were observed in processed food samples. However, the prevalence of ESBL-producing Citrobacter freundii in raw food samples was high (p = 0.03). Among the isolates, 55% were blaCTX-M, 26% were blaSHV, and 19% were blaTEM. Notably, heavy metal resistance was highly prevalent in ESBL producers. These findings demonstrate that retail food samples are exposed to contaminants including antibiotics and heavy metals, endangering consumers.

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Evaluation of bacterial strains isolated from Late Quaternary alluvial sediments spanning ~ 28 m in depth for heavy metal tolerance and Cr(VI) removal ability

International Microbiology ◽

10.1007/s10123-021-00174-0 ◽

2021 ◽

Author(s):

Abhi P. Shah ◽

G. Archana

Keyword(s):

Heavy Metal ◽

Metal Tolerance ◽

Late Quaternary ◽

Heavy Metal Tolerance ◽

Bacterial Strains ◽

Alluvial Sediments

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Effect of Lead and Copper on Photosynthetic Apparatus in Citrus (Citrus aurantium L.) Plants. The Role of Antioxidants in Oxidative Damage as a Response to Heavy Metal Stress

Plants ◽

10.3390/plants10010155 ◽

2021 ◽

Vol 10 (1) ◽

pp. 155

Author(s):

Anastasia Giannakoula ◽

Ioannis Therios ◽

Christos Chatzissavvidis

Keyword(s):

Oxidative Stress ◽

Lipid Peroxidation ◽

Heavy Metal ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Membrane Integrity ◽

Photosynthetic Apparatus ◽

Heavy Metal Stress ◽

Photosynthetic Parameters ◽

Citrus Aurantium

Photosynthetic changes and antioxidant activity to oxidative stress were evaluated in sour orange (Citrus aurantium L.) leaves subjected to lead (Pb), copper (Cu) and also Pb + Cu toxicity treatments, in order to elucidate the mechanisms involved in heavy metal tolerance. The simultaneous effect of Pb− and Cu on growth, concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophylls, flavonoids, carotenoids, phenolics, chlorophyll fluorescence and photosynthetic parameters were examined in leaves of Citrus aurantium L. plants. Exogenous application of Pb and Cu resulted in an increase in leaf H2O2 and lipid peroxidation (MDA). Toxicity symptoms of both Pb and Cu treated plants were stunted growth and decreased pigments concentration. Furthermore, photosynthetic activity of treated plants exhibited a significant decline. The inhibition of growth in Pb and Cu-treated plants was accompanied by oxidative stress, as indicated by the enhanced lipid peroxidation and the high H2O2 concentration. Furthermore, antioxidants in citrus plants after exposure to high Pb and Cu concentrations were significantly increased compared to control and low Pb and Cu treatments. In conclusion, this study indicates that Pb and Cu promote lipid peroxidation, disrupt membrane integrity, reduces growth and photosynthesis and inhibit mineral nutrition. Considering the potential for adverse human health effects associated with high concentrations of Pb and Cu contained in edible parts of citrus plants the study signals that it is important to conduct further research into the accessibility and uptake of the tested heavy metals in the soil and whether they pose risks to humans.

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