Influence of Heavy Metal Stress on Antioxidant Status and DNA Damage inUrtica dioica

Abstract

Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity.

Heavy metals and their general toxicity for plants

“…The main toxic effects of heavy metals over antioxidant system are seen in the increase in activity of some enzymes, depletion of depot of low molecular weight antioxidants and generation of ROS. There is a variety of studies in various plant species subjected to heavy metal stress that reported the antioxidant activity effects on plants (2, 17,51,52 …”

Effects of Heavy Metals from Soil and Dust Source on DNA Damage of the Leymus chinensis Leaves in Coal-Mining Area in Northwest China

“…Surface mining operations, collection, transportation and handling of coal are the major sources of such fugitive emission[1], and these emissions can contribute significantly to heavy metal contamination around mining areas[2]. Moreover, heavy metals from these emissions are easily absorbed by plants, animals and human beings exposed to these elements[3], and can cause genetic damage on some extent[4]. …”

“…Monterroso et al[12] identified metal-tolerant plants with potential application in phytoremediation strategies, evaluated the distribution and chemical fractionation of heavy metals in soils and their accumulation or exclusion by native plant species growing in an abandoned Pb/Zn mine in North Western Spain. Gjorgieva et al[4] investigated effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems. The results suggested that heavy metal stress influenced antioxidant status and also induced DNA damages in U .…”

Genotoxicity assessment of pesticides on terrestrial snail embryos by analysis of random amplified polymorphic DNA profiles

“…RAPD has been successfully used on many organisms, such as plants [5][6][7], algae [8,9], and fish [10][11][12][13][14]. This technique has been used to detect signs of genotoxicity from various contaminants, including non-essential metals, such as cadmium, boron, arsenic, mercury, nickel, and aluminum [15][16][17][18][19], and essential metals, such as zinc, sodium, manganese, and copper [6,7,9,[20][21][22].…”

“…This technique has been used to detect signs of genotoxicity from various contaminants, including non-essential metals, such as cadmium, boron, arsenic, mercury, nickel, and aluminum [15][16][17][18][19], and essential metals, such as zinc, sodium, manganese, and copper [6,7,9,[20][21][22]. RAPD has also been used to demonstrate the genotoxicity of various physical compounds, such as UV A and B [8] and gamma rays [23], the radioactivity of uranium and tritium [24,25] and emergent pollutant nanoparticles, such as ZnO and CuO [26].…”