Iron plaque formation in the roots of Pistia stratiotes L.: importance in phytoremediation of cadmium

Abstract

Aquatic macrophytes play an important role in the removal of toxic metals from wastewater. Therefore, the induction of Fe plaque on the roots, and its consequences on Cd tolerance investigated in an aquatic macrophyte Pistia stratiotes L. The presence of Fe²⁺ ion but not Fe³⁺ resulted in Fe plaque formation. Induction of Fe plaque decreased Ca and increased K and Fe accumulations in the root. Plaque formed plants had accumulated less Cd until 50.0 µM CdCl₂ treatments because plaque acted as a barrier to Cd exposure. However, at higher concentrations (500.0 µM CdCl₂), plaque formed plants contained more Cd in the roots. Cadmium inducible ion leakage in the root and lowering of the photosynthetic pigment content were less in plants with a plaque. Stretching of aromatic carbonyl groups and alkyl groups among plaque formed plants upon Cd treatments indicated the putative role of phenolics in Cd detoxification.

Keywords:

• Aquatic macrophyte
• aerenchyma
• acidic pH
• ion leakage
• malondialdehyde
• metal tolerance
• phenolics

Acknowledgment

Thanks are due to the University of Hyderabad for the facility.

Disclosure statement

KST and AS equally contributed in the manuscript with the supervision of MNVP.