Journal of Degraded and Mining Lands Management
Vol 1, No 1 (2013)

Tolerance mechanisms in mercury-exposed Chromolaena odorata (l.f.) R.M. King et H. Robinson, a potential phytoremediator

H J P Alcantara (School of Chemisty, University of Melbourne)
G C Rivero (School of Chemisty, University of Melbourne)
J M Puzon (School of Chemisty, University of Melbourne)



Article Info

Publish Date
30 Oct 2013

Abstract

Chromolaena odorata (L.f.) R.M. King et H. Robinson plants were grown in Hoagland’s solutions with 0.00 ppm and 1.00 ppm Hg(NO3)2. The calcium, magnesium, iron, and sulfur levels in the leaves were found to be not significantly affected by presence of the uptaken Hg2+. The chlorophyll a, chlorophyll b, and total chlorophyll contents of its leaves also remained within normal levels, which may indicate that the photosynthetic machinery of the Hg-exposed C. odorata was unaffected by the presence of Hg2+. The results of the ICP-AES analyses of the Hg2+ contents established the presence of Hg2+ in all the subcellular components obtained from the leaves of the Hg-treated C. odorata plants, and that the ultimate localization of Hg2+ is in the vacuoles. The findings revealed no significant differences in the degree of oxidative injury between the cells from the control and Hg-treated plants, as evidenced by the low lipid peroxidation levels obtained with the TBARS assay. The SH-containing biomolecules that were initially detected through DTNB assay manifested a predominant peak in the RP-HPLC chromatographs of both the control and Hg-treated plants, with their retention times falling within the ranges of GSH, MT, and cysteine standards. However, the concentrations of the GSH- and/or MT-like, Cys-containing biomolecules detected in the leaves of Hg-treated C. odorata plants were ten times higher than those of the control.The findings of this study suggest that the enhanced antioxidative capacity, the production of Hg-binding biomolecules, and the localization of Hg2+ ions ultimately in the vacuoles of the leaves are the mechanisms which bring about Hg2+ tolerance and homeostasis in C. odorata plant. These results indicate that C. odorata is a potentially effective phytoremediator for Hg2+.

Copyrights © 2013






Journal Info

Abbrev

jdmlm

Publisher

Subject

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology

Description

Journal of Degraded and Mining Lands Management is managed by the International Research Centre for the Management of Degraded and Mining Lands (IRC-MEDMIND), research collaboration between Brawijaya University, Mataram University, Massey University, and Institute of Geochemistry, Chinese Academy of ...