Mineral nutrient imbalance, total antioxidants level and DNA damage in common bean (Phaseolus vulgaris L.) exposed to heavy metals

Abstract

The present study aimed to analyze the biological effects induced by bioaccumulation of metals in common bean (Phaseolus vulgaris L.). Effects of mineral nutrient imbalance, total antioxidants level and DNA damage induced by accumulation of heavy metals, were investigated in bean seedlings treated with two selected metal concentrations for 7 days. Metal content is analyzed by inductively coupled plasma -atomic emission spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay is used and Random Amplified Polymorphic DNA (RAPD) method was applied for investigation of DNA damages. The increasing metal concentration in the treatment medium changed synchronously metal content in samples, and decreased total antioxidant activity in all samples with exception only for samples treated with Ni and Cd. The obtained "DNA fingerprints" demonstrated that the increasing metal concentrations induced changes in RAPD profiles (disappearance and/or appearance of bands in comparison with untreated control samples). The highest number of missing bands was observed in samples treated with zinc (total 4 bands) and nickel (total 4 bands) at both concentrations. These results suggested that mineral nutrient imbalance is involved in changes of antioxidant levels and DNA damages of the seedlings, which may help to understand the mechanism of metal toxicity in plants.

Melatonin Modulates Plant Tolerance to Heavy Metal Stress: Morphological Responses to Molecular Mechanisms

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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 …”

Presence of arsenic and potentially toxic metals (Cd, Cr, Pb) in water and soil of the NE shore of Chapala Lake, Mexico, and its genotoxic effect in the edible chayote fruit (Sechium edule (Jacq.) Sw.)

“…The presence of diverse metals in the water used to irrigate agricultural crops, as well as their accumulation in soil and crops, can produce a genotoxic affectation that limits adequate development during the plant's vegetative cycle, as well as the yield and nutritional quality of the crop (Maleki et al, 2017). Pollutants predominantly of industrial and agricultural origin can generate cellular stress and cause damage at different levels, including DNA (Moura et al, 2012;Gjorgieva et al, 2013;Siddiqui, 2015). Given that Lake Chapala is endangered (Hansen and Maya, 1997;Rosales-Hoz et al, 2000;Jay and Ford, 2001;Global Nature Fund, 2009;Ontiveros-Cuadras et al, 2014), the potential conflict over regional water resources is high due to overexploitation and contamination.…”