lead accumulation and distribution at cellular level in native plants growing on battery wastes contaminated sites in Ibadan, Nigeria

Introduction: Effective phytoextraction depends on the identification of fast growing plants that can tolerate and accumulate high concentration of metals in their tissue. This study was conducted to identify potential lead hyperaccumulators among the native plant species growing on two abandoned lead-acid battery waste-contaminated sites.

Methodology: Plant samples were collected in triplicates from these sites. Pb accumulation in different parts, translocation (TF) and bioaccumulation factors (BCF) as well as cellular distribution of Pb among the cell organelles (cell wall, mitochondria, plastids, nucleus and soluble fraction) were determined.

Results: Among the plant species (Gomphrena celosioides, Sporobolus pyramidalis, Imperata cylindrica, Chromolaena odorata, Cynodon. dactylon, Rhynchospora corymbosa and Eleusine indica) found on these sites, G. celosioides had the highest Pb concentration (12, 657 mg/kg ) in its shoot and the highest BCF (18.66) and TF (25.62) while others had TF and BCF values that were less than 1. S. pyramidalis and E. indica had lower Pb accumulation. Pb was mostly accumulated in the cell wall and there was an increase in the production of phenolics, flavonoids and chlorophyll.

Conclusion: G. celosioides can therefore be described as a Pb hyperaccumulator and its Pb is mostly accumulated in the cell wall.