Nickel accumulation, localisation and the biochemical responses in Eclipta prostrata (L.) L

Abstract

ABSTRACTThe objective of the study was to examine the growth, accumulation and biochemical responses in Eclipta prostrata (L.) L., at increasing levels of nickel in soil after 30 days of treatment. Accumulation of nickel in different parts of the plant was found in a concentration-dependent manner, and the uptake was significantly higher in roots than in shoots. Lipid peroxidation was significantly increased in the metal-exposed plant, compared with the control. The plant exhibited a significant decrease in its pigment content at Ni treatment levels from 100 mg/kg onwards. Compared with the control, a significant increase was observed in the metal exposed plant in its non-enzymatic antioxidants such as proline, flavonoid and phenolic compounds, as well as in the activity of enzymatic antioxidants like superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase. The present study revealed the mechanism adopted by E. prostrata in alleviating nickel-induced oxidative damage. Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) provided supporting evidence for the uptake of heavy metals, localisation and binding or interaction of nickel in the leaf. Thus, the plant appears to have the potential as a tolerant nickel phytoremediator species for application in decontamination of moderately polluted soils.