Aluminium Induced Oxidative Stress and DNA Damage in Root Cells of Allium cepa L

Molecular Biology and Tissue Culture Laboratory, Department of Botany, Berhampur University, Berhampur 760007, India.
Ecotoxicology and Environmental Safety (Impact Factor: 2.76). 07/2008; 70(2):300-10. DOI: 10.1016/j.ecoenv.2007.10.022
Source: PubMed


Aluminium (Al) was evaluated for induction of oxidative stress and DNA damage employing the growing roots of Allium cepa L. as the assay system. Intact roots of A. cepa were treated with different concentrations, 0, 1, 10, 50, 100, or 200 microM of aluminium chloride, at pH 4.5 for 4 h (or 2 h for comet assay) at room temperature, 25+/-1 degrees C. Following treatment the parameters investigated in root tissue were Al-uptake, cell death, extra cellular generation of reactive oxygen intermediates (ROI), viz. O(2)(*-), H(2)O(2) and (*)OH, lipid peroxidation, protein oxidation, activities of antioxidant enzymes namely catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX); and DNA damage, assessed by comet assay. The findings indicated that Al triggered generation of extra-cellular ROI following a dose-response. Through application of specific enzyme inhibitors it was demonstrated that extra-cellular generation of ROI was primarily due to the activity of cell wall bound NADH-PX. Generation of ROI in root tissue as well as cell death was better correlated to the levels of root Al-uptake rather than to the concentrations of Al in ambient experimental solutions. Induction of lipid peroxidation and protein oxidation by Al were statistically significant. Whereas Al inhibited CAT activity, enhanced SOD, GPX and APX activities significantly; that followed dose-response. Comet assay provided evidence that Al induced DNA damage in a range of concentrations 50-200 microM, which was comparable to that induced by ethylmethane sulfonate (EMS), an alkylating mutagen served as the positive control. The findings provided evidence that Al comparable to biotic stress induced oxidative burst at the cell surface through up- or down-regulation of some of the key enzymes of oxidative metabolism ultimately resulting in oxidative stress leading to DNA damage and cell death in root cells of A. cepa.

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Available from: Brahma B. Panda, Oct 13, 2015
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    • "DNA damage was detected in all versions of comet assays. Achary et al., 2008 Al 3þ Aluminium chloride induced DNA damage with a dose-dependent pattern. Georgieva and Stoilov, 2008 Bleomycin A dose-dependent increase of DNA in tail was observed and at higher concentration, the share of type 4 comets gradually increased. "
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    ABSTRACT: The comet assay is a sensitive technique for the measurement of DNA damage in individual cells. Although it has been primarily applied to animal cells, its adaptation to higher plant tissues significantly extends the utility of plants for environmental genotoxicity research. The present review focuses on 101 key publications and discusses protocols and evolutionary trends specific to higher plants. General consensus validates the use of the percentage of DNA found in the tail, the alkaline version of the test and root study. The comet protocol has proved its effectiveness and its adaptability for cultivated plant models. Its transposition in wild plants thus appears as a logical evolution. However, certain aspects of the protocol can be improved, namely through the systematic use of positive controls and increasing the number of nuclei read. These optimizations will permit the increase in the performance of this test, namely when interpreting mechanistic and physiological phenomena. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Environmental Pollution 08/2015; 207:6-20. DOI:10.1016/j.envpol.2015.08.020 · 4.14 Impact Factor
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    • "Enhancement of peroxidation of phospholipids in Glycine max (soybean) roots was the first report on the involvement of ROS of Al toxicity in plants (Cakmak and Horst 1991). Since then, several lines of evidences from physiological and genetical studies have supported this idea in plant cells (Jones et al. 2006; Achary et al. 2008; Tahara et al. 2008). Recently Yin et al. (2010) reported highly electrophilic α,β-unsaturated aldehydes (2-alkenals), the lipid peroxide-derived aldehyde, participate in oxidative stress induced by Al in tobacco roots. "
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    ABSTRACT: Achieving sustainable food production to feed the increasing population of the problematic lands of the world is an enormous challenge. Aluminum (Al) toxicity in the acid soil is a major worldwide problem. Liming and nutrient management technologies are worthless due to high lime requirement, and the effect of liming does not persist for long. Besides this, conventional breeding is useful to manage Al toxicity as some plants have evolved mechanisms to cope with Al toxicity in acid soil. Therefore, understanding of Al tolerance mechanisms is prime necessity for improving Al tolerance in crops. Al resistance mechanisms include mainly Al avoidance (Al exclusion) and/or Al tolerance (detoxification of Al inside the cell) mechanisms. In this chapter, we summarize Al behavior in plant root cell. We include recent findings of Al resistance mechanisms and Al-resistant genes which can be useful to produce cultivars adapted to acid soils.
    Stress Responses in Plants, Edited by BN Tripathi and Maria Mueller, 07/2015; Springer.
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    • "Aluminum (Al), the third most abundant metal in the earth's crust, consists of 8 % of its mass (Achary et al. 2008). Al in the environment occurs in the process of smelting, which become part of the soil either directly through the precipitation or dry deposition, or indirectly through contaminated litter. "
    Environmental Science and Pollution Research 09/2014; · 2.83 Impact Factor
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