Tolerance and hyperaccumulation of cadmium by a wild, unpalatable herb Coronopus didymus (L.) Sm. (Brassicaceae)

Ecotoxicol Environ Saf. 2017 Jan:135:209-215. doi: 10.1016/j.ecoenv.2016.10.001. Epub 2016 Oct 13.

Abstract

The potential of a wild, unpalatable plant Coronopus didymus was investigated for the first time in terms of its capability to tolerate and accumulate cadmium (Cd) for phytoremediation purposes. A screenhouse experiment for 6 weeks was conducted to evaluate the effect of Cd from 100 to 400mgkg-1 on growth, biomass, photosynthetic apparatus, Cd uptake and accumulation in C. didymus plants. Application of Cd facilitates the growth of the plants whereas at higher levels a slight reduction was noticed. The concentration of Cd in roots and shoots reached a maximum of 867.2 and 864.5mgkg-1 DW respectively, at 400mgkg-1Cd treatment. Cd exposure increased the generation of superoxide anion (O2•-), H2O2 content, MDA level and antioxidative response (SOD, CAT and POD) in roots and shoots of C. didymus. However, a slight decline in SOD and CAT activities were noticed in roots at highest Cd treatment (400mgkg-1). The bioconcentration (BCF) values for all the concentrations were ˃1 and the translocation factor (TF) values were ˂ 1 at lower level but reached 1 at highest Cd concentration. Thus, C. didymus satisfies the conditions required for hyperaccumulator plants and may be practically employed to alleviate Cd from contaminated soils.

Keywords: Bioconcentration factor; Cadmium; Coronopus didymus; Hyperaccumulator; Translocation factor.

MeSH terms

  • Antioxidants
  • Biodegradation, Environmental*
  • Biomass
  • Brassicaceae / drug effects
  • Brassicaceae / growth & development
  • Brassicaceae / metabolism*
  • Cadmium / administration & dosage
  • Cadmium / metabolism*
  • Cadmium / toxicity
  • Catalase / metabolism
  • Hydrogen Peroxide / metabolism
  • Malondialdehyde / metabolism
  • Peroxidase / metabolism
  • Photosynthesis / drug effects
  • Plant Roots / metabolism*
  • Plant Shoots / metabolism*
  • Soil Pollutants / metabolism*
  • Superoxide Dismutase / metabolism
  • Superoxides / metabolism

Substances

  • Antioxidants
  • Soil Pollutants
  • Cadmium
  • Superoxides
  • Malondialdehyde
  • Hydrogen Peroxide
  • Catalase
  • Peroxidase
  • Superoxide Dismutase