pH changes and organic acids exudation by Eriophorum angustifolium roots exposed to elevated concentration of toxic elements
(English)Article in journal (Refereed) Submitted
This study was aimed to investigate the influence of Eriophorum angustifolium roots on surrounding water pH in the presence of heavy metals and As, and the possible mechanism behind. We monitored the pH in the surrounding nutrient solution by E. angustifolium roots at a starting pH 3.5 and in the presence of a combination of As, Pb, Cu, Cd and Zn at different concentrations. The metal and As contents in the plant shoots and roots were analyzed as well as organic acids in the root exudates. Fluorescence microscopy and a pH-specific fluorescent dye were used to investigate the influence of different elements on apoplastic pH of E. angustifolium roots. The results showed that the roots have the ability to increase the rhizosphere pH even in the presence of different free metal ions and As. The plant root metal and As contents were significantly higher as compared with shoots. Metal and As treatment at higher concentrations significantly caused the apoplastic pH to increase in this species. Of the acids analyzed, the exudation of the oxalic, formic and succinic acids was significantly enhanced after metal and As exposure, as compared with control, giving the maximum concentration of these acids after 25 µM As, Cu, Zn, Pb and 2.5 µM Cd treatment. The roots of E. angustifolium respond to toxic ions by releasing organic acids, which transiently induce rhizosphere basification.
Eriophorum angustifolium, Heavy metals and As, pH changes, Organic acids, Phytostabilization
Research subject Plant Physiology
IdentifiersURN: urn:nbn:se:su:diva-64327OAI: oai:DiVA.org:su-64327DiVA: diva2:457078
In thesis, Mechanisms behind pH changes by plant roots and shoots caused by elevated concentration of toxic elements2011-11-162011-11-162011-11-17Bibliographically approved