Phytoextraction of Chromium VI by Raphanus sativus L. under exogenous application of citric acid

Abstract

The pollution of environment by toxic heavy metals has increased dramatically over the past decades due to various sources of contamination, mainly industrial and human activities. Soil is the main recipient of air and water contamination. In this study, we evaluated the ability of radish plants to accumulate chromium VI (Cr(VI)) (150 ppm) under the application of citric acid (CA) (15 mM). The results showed that Cr(VI) reduced shoot dry weight, root dry weight, hypocotyl dry weight, and total chlorophyll content. On the other hand, Cr(VI) increased H2O2, malondialdehyde, and antioxidant activities of the radish plant. However, the application of CA improved the growth and physiological parameters and antioxidant content (superoxide dismutase 5 % and 4 %, peroxidase content 24 % and 4.25 %, catalase 38 % and 28 %, and ascorbate peroxidase 4 % and 35 %) in root and shoot part respectively, and increases the accumulation of Cr(VI) in different parts of the radish plant.