EVALUATION OF IRON ON CADMIUM UPTAKE BY TOMATO, MOREL AND LEAF RED BEET IN HYDROPONIC CULTURE

Abstract

The objective of this research was to determine the effect of iron (Fe) deficiency on the uptake of cadmium (Cd) by three plants: tomato (Lycopersicon esculentum Mill.), morel (Solanum nigrum L.), and leaf red beet (Beta vulgaris var.cicla L.) in hydroponic culture. We also investigated the influence of Fe deficiency on rhizosphere pH, bioconcentration factor (BCF), and translocation factor (TF) in three plants. The plants were grown in Hoagland's solution for 28 days, then some plants were still in full strength Hoagland's solution (+Fe) for seven days, the others were generated in full strength Hoagland's solutions without Fe (−Fe) for seven days. After the seedlings had grown for five weeks, the seedlings were exposed for four daysat concentrations of Cd 0 mg L⁻¹ (control), 0.1 mg L⁻¹, and 1 mg L⁻¹. The results showed that Fe deficiency induced Cd uptake, biomass decrease and solution pH decrease in hydroponic culture by three plants. Values of BCF and TF indicated that three plants had dissimilar abilities of phytoextraction and transportation of heavy metals under Fe deficiency status, but BCF and TF of Fe-deficient plants were higher compared to Fe sufficient ones at different Cd concentrations. These results suggested Fe deficiency induced the change of root exudation and rhizosphere, which enhance Cd bioavailability. Therefore, Fe-deficient plants accumulated more Cd than Fe-sufficient ones.

Keywords:

• phytoremediation
• Fe deficiency
• plants
• cadmium

ACKNOWLEDGMENTS

This study was financially supported by the National High-Tech Research Progress Plan (863) (No. 2007AA06A405).