Improved of growth and phytostabilization potential of lead (Pb) in Glebionis coronaria L. under the effect of IAA and GA₃ alone and in combination with EDTA by altering biochemical attributes of stressed plants

This study evaluated the effect of EDTA, IAA and GA₃ alone and in combination in improving plant growth, Pb accumulation, and management of effective mechanisms associated with alleviation of Pb-induced adverse effect in Glebionis coronaria L. grown on industrial area in Alexandria. In this regards, 10-week-old plants were subjected to IAA and GA₃ as a foliar spray and EDTA was supplied in two doses 50 and 200mgkg⁻¹ soil. EDTA significantly reduced the plant growth and dry biomass, whereas GA₃ and IAA foliar spray increased growth significantly when compared with control (uncontaminated soil). In combined treatments of EDTA + GA₃ +IAA, the biomass was restored, which shows that GA₃ and IAA did compensate the negative effect of EDTA on plant growth and increased the Pb uptake significantly into roots. There were high GSH contents parallel with the increase of glutathione-S-transferase activity and induction of the antioxidant enzymes (SOD, CAT, APX, GR) as well as oxidized glutathione and ascorbic acid contents in leaves and roots when compared to control plants. This study suggests that G. coronaria is promising species for decontamination of Pb -contaminated soil and the application of EDTA together with IAA and GA₃ could be a useful strategy for enhancing the phytostabilization capability of Glebionis coronaria L. to eliminate Pb from contaminated soils. Novelty statement: The objective of this paper is to investigate the physiological performance of Glebionis coronaria as a new native for phytoremediation by phytostabilization mechanism of Pb after treatment with EDTA and phytohormones. Chemical additives of EDTA and GA₃ as well as IAA are promising alternatives to provide added benefits due to their individual credentials in improving the overall phytostabilization effectiveness and better immobilization efficiency in treating Pb contaminated soils by altering biochemical attributes of stressed plants. Currently these additives are not employed widely in large-scale field implementations, so field applications of these additives using Glebionis coronaria are essential for Phytoremediation of Pb-contaminated soils.