Effect of heavy metal and EDTA application on heavy metal uptake and gene expression in different Brassica species

Abstract

The present study investigates the effect of different concentration of heavy metals (Cd, Cr and Pb) and ethylenediaminetetraacetic acid (EDTA) application on two Brassica species (Brassica carinata and Brassica juncea). EDTA application had significant (p<0.05) effect on shoot length, shoot fresh weight, shoot dry weight, root length, root fresh weight, root dry weight and accumulation of heavy metals in both species. Species also produced significant (p<0.05) effect on all parameters except shoot length of the plant. The effect of heavy metals on shoot length, shoot fresh weight, root fresh weight and accumulation of heavy metals was also reported to be significant (p<0.05). Interaction between heavy metals × species showed a significant (p<0.05) effect on shoot fresh weight, shoot dry weight, root length and accumulation of heavy metal in both Brassica species. The data reveal that maximum shoot length, shoot fresh weight, shoot dry weight, root fresh weight and root dry weight was achieved by control plants. In addition, maximum heavy metals (142.88 mg kg^-1) were observed for B. juncea that were grown under 150 mg kg^-1 Pb and 0 mM EDTA stress. Exposure of Brassica species to heavy metals and EDTA resulted in the expression of newly synthesized and abundantly expressed polypeptides, which may play a role in phytoremediation.

Keywords: Brassica, phytoextraction, heavy metals, EDTA, gene expression