Enhancing the lead phytostabilization in wetland plant Juncus effusus L. through somaclonal manipulation and EDTA enrichment

Abstract

We investigated the role of ethylene diamine tetra-acetic acid (EDTA) and somaclonal manipulation on improving lead (Pb) phytostabilization in mat rush (Juncus effusus L.). Seedlings were raised from seeds and callus to study variations in Pb uptake and tolerance. The seedlings were treated with 0.5 and 1.0 mM Pb as alone, and each with 2.5 and 5.0 mM of EDTA. Plants grown from both sources accumulated relatively larger Pb contents in their root tissues that were further enhanced by EDTA supplementation in the hydroponics medium. The tendency of storing higher Pb contents in roots compared to shoots in J. effusus was also evident from lower translocation factor (TF) value that facilitated the plants to avoid from Pb-induced shoot injury. Callus grown plants were more responsive to EDTA amendment showing improved growth, Pb uptake and chlorophyll contents under Pb stress. Both kinds of J. effusus plants tolerated Pb toxicity by modifying antioxidative enzyme activities. Enrichment of Pb-treated media with EDTA further elevated enzymic activities of plant roots contributing to defy Pb-induced oxidative burst. Thus, plant improvement through somaclonal manipulation in J. effusus along with EDTA enrichment could be an appropriate technique for phytostabilization of Pb-contaminated environments.