Metal(loid) induced toxicity and defense mechanisms in Spinacia oleracea L.: Ecological hazard and Prospects for phytoremediation

Ecotoxicol Environ Saf. 2019 Nov 15:183:109570. doi: 10.1016/j.ecoenv.2019.109570. Epub 2019 Aug 20.

Abstract

A pot study was conducted to assess the phytoremediation potential of Spinach plants along with their physiological and biochemical response when grown in soil contaminated with heavy metal(loid)s (HMs). Plants were grown under different doses of Pb, Cd and As; and their metal(loid) accumulation efficiency was studied upon harvest; expressed in terms of bioabsorption coefficient (BAC), bioconcentration factor (BCF) and translocation factor (TF). Results showed significant (p ≤ 0.05) difference in physiological and biochemical mechanisms of plants as detected through decrease in concentration of cellular constituents (pigments, carbohydrates, total nitrogen content); and increase in antioxidants (both enzymatic and non-enzymatic). Despite of accumulating high amount of HMs in tissues, no visible signs of toxicity were seen; and hence the efficient survival and defense mechanism shown by spinach plants conclude that they are a viable option to be used for phytoremediation of sites contaminated with Cd and Pb. Since the content of Cd and Pb in edible part was higher than safe limits prescribed by USEPA, the present investigation also highlights the ecological hazards that may result upon cultivation of spinach in contaminated soil for agricultural purpose; or its accidental exposure to food chain when grown for phytoremediation.

Keywords: Hazard quotient; Heavy metal; Phytoextraction.

MeSH terms

  • Agriculture
  • Antioxidants / metabolism*
  • Biodegradation, Environmental
  • Ecology
  • Metalloids / analysis
  • Metalloids / toxicity*
  • Metals, Heavy / analysis
  • Metals, Heavy / toxicity*
  • Soil / chemistry
  • Soil Pollutants / analysis
  • Soil Pollutants / toxicity*
  • Spinacia oleracea / drug effects*
  • Spinacia oleracea / growth & development
  • Spinacia oleracea / metabolism

Substances

  • Antioxidants
  • Metalloids
  • Metals, Heavy
  • Soil
  • Soil Pollutants