Molecular Mechanisms of Heavy Metal Tolerance in Plants

2020 ◽  
pp. 125-136
Author(s):  
Nasser Delangiz ◽  
Bahman Khoshru ◽  
Behnam Asgari Lajayer ◽  
Mansour Ghorbanpour ◽  
Solmaz Kazemalilou
Keyword(s):  
Heavy Metal ◽  
Molecular Mechanisms ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance

Molecular mechanisms of heavy metal tolerance and evolution in invertebrates

2009 ◽  
Vol 16 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Thierry K. S. Janssens ◽  
Dick Roelofs ◽  
Nico M. van Straalen
Keyword(s):  
Heavy Metal ◽  
Molecular Mechanisms ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance

scholarly journals ScMT2-1-3, a Metallothionein Gene of Sugarcane, Plays an Important Role in the Regulation of Heavy Metal Tolerance/Accumulation

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Jinlong Guo ◽  
Liping Xu ◽  
Yachun Su ◽  
Hengbo Wang ◽  
Shiwu Gao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Molecular Mechanisms ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
E Coli ◽  
Metal Ion Homeostasis ◽  
Metallothionein Gene ◽  
Tolerance Accumulation ◽  
And Storage

Plant metallothioneins (MTs), which are cysteine-rich, low-molecular-weight, and metal-binding proteins, play important roles in detoxification, metal ion homeostasis, and metal transport adjustment. In this study, a novel metallothionein gene, designated asScMT2-1-3(GenBank Accession number JQ627644), was identified from sugarcane.ScMT2-1-3was 700 bp long, including a 240 bp open reading frame (ORF) encoding 79 amino acid residues. A His-tagged ScMT2-1-3 protein was successfully expressed inEscherichia colisystem which had increased the host cell’s tolerance to Cd2+, Cu2+, PEG, and NaCl. The expression ofScMT2-1-3was upregulated under Cu2+stress but downregulated under Cd2+stress. Real-time qPCR demonstrated that the expression levels ofScMT2-1-3in bud and root were over 14 times higher than those in stem and leaf, respectively. Thus, both theE. coliassay and sugarcane plantlets assay suggested thatScMT2-1-3is significantly involved in the copper detoxification and storage in the cell, but its functional mechanism in cadmium detoxification and storage in sugarcane cells needs more testification though its expressed protein could obviously increase the hostE. colicell’s tolerance to Cd2+.ScMT2-1-3constitutes thus a new interesting candidate for elucidating the molecular mechanisms of MTs-implied plant heavy metal tolerance/accumulation and for developing sugarcane phytoremediator varieties.

scholarly journals Molecular Responses to Cadmium Exposure in Two Contrasting Durum Wheat Genotypes

2021 ◽  
Vol 22 (14) ◽  
pp. 7343
Author(s):  
Erika Sabella ◽  
Andrea Luvisi ◽  
Alessandra Genga ◽  
Luigi De Bellis ◽  
Alessio Aprile
Keyword(s):  
Heavy Metal ◽  
Transcription Factors ◽  
Durum Wheat ◽  
Molecular Mechanisms ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Ros Scavenging ◽  
Metal Transporters ◽  
New Findings ◽  
Cd Translocation

Cadmium is a heavy metal that can be easily accumulated in durum wheat kernels and enter the human food chain. Two near-isogenic lines (NILs) with contrasting cadmium accumulation in grains, High-Cd or Low-Cd (H-Cd NIL and L-Cd NIL, respectively), were used to understand the Cd accumulation and transport mechanisms in durum wheat roots. Plants were cultivated in hydroponic solution, and cadmium concentrations in roots, shoots and grains were quantified. To evaluate the molecular mechanism activated in the two NILs, the transcriptomes of roots were analyzed. The observed response is complex and involves many genes and molecular mechanisms. We found that the gene sequences of two basic helix–loop–helix (bHLH) transcription factors (bHLH29 and bHLH38) differ between the two genotypes. In addition, the transporter Heavy Metal Tolerance 1 (HMT-1) is expressed only in the low-Cd genotype and many peroxidase genes are up-regulated only in the L-Cd NIL, suggesting ROS scavenging and root lignification as active responses to cadmium presence. Finally, we hypothesize that some aquaporins could enhance the Cd translocation from roots to shoots. The response to cadmium in durum wheat is therefore extremely complex and involves transcription factors, chelators, heavy metal transporters, peroxidases and aquaporins. All these new findings could help to elucidate the cadmium tolerance in wheat and address future breeding programs.

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

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.

scholarly journals 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 ◽  
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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