<i>In vitro</i> breeding of grey poplar (<i>Populus</i> × <i>canescens</i>) for phytoremediation purposes

Abstract

Abstract BACKGROUND: Paraquat‐tolerant poplar ( Populus × canescens ) clones (PQT) were selected in in vitro nodal segment cultures at the sublethal paraquat concentration (0.4 µmol L −1 ). After testing on tissue culture media, regenerants were micropropagated, rooted and transplanted to a greenhouse followed by a field test at heavily contaminated fields of the Chemical Company Balatonfüzfö (Hungary). RESULTS: PQT clones showed significantly higher gst (glutathione S‐transferase) gene expression level than the wild type (WT) analyzed by qRT‐PCR (quantitative reverse transcriptase real time PCR). The expression level of gst gene in the PQT clones showed 70‐fold (without paraquat treatment), 4‐fold (at 0.1 µmol L −1 paraquat), 20‐fold (at 0.4 µmol L −1 paraquat) and 40‐fold (at 1 µmol L −1 paraquat) increments compared with WT. For functional analysis, enzyme activities of lipoxygenase (LOX; EC 1.13.11.12), glutathione S‐transferase (GST; EC 2.5.1.18), ascorbate peroxidase (APOX; EC 1.11.1.11) and glutathione reductase (GR; EC 1.6.4.2) were determined. The enzyme activity of GR and LOX, and the glutathione content (GSH) were found to be significantly higher in PQT clones. CONCLUSIONS: Paraquat‐tolerant clones as powerful new stress tolerant and non‐GMO plants can provide an effective tool for phytoremediaton purposes where the pollutants cause oxidative stresses. Copyright © 2009 Society of Chemical Industry