Reference

EDTA (Ethylenediaminetetraacetic acid) plays a significant role in enhancing the transport and accumulation of lead (Pb) in Indian mustard (Brassica juncea). The primary mechanisms by which EDTA aids this process are:

1. Solubilization of Lead: EDTA acts as a chelating agent, binding with lead ions in the soil to form Pb-EDTA complexes. This chelation significantly increases the solubility of lead, making it more available for plant uptake [source].

2. Enhanced Mobility: The Pb-EDTA complex is more mobile within the plant system compared to lead ions alone. EDTA facilitates the transport of lead from the roots to the shoots of the plants. Studies have shown that Indian mustard exposed to Pb and EDTA in hydroponic solutions can accumulate up to 55 mmol kg^-1 of lead in dry shoot tissue [source].

3. Increased Uptake: By sequestering lead in a form that is more easily transported within the plant, EDTA enhances the overall uptake of lead by the plants. This chelation process minimizes the negative effects of lead toxicity and helps in its translocation to the aerial parts of the plant [source].

4. Transport Mechanism: The ability of EDTA to bind tightly with lead ions helps in overcoming the usual limitations posed by the immobility of lead in soil. As a result, the Pb-EDTA complex can move through the plant's vascular system more effectively, allowing higher concentrations of lead to be accumulated in the shoots and leaves of Indian mustard [source].

Below are some visual aids depicting these processes:

By utilizing EDTA, researchers can significantly enhance the phytoremediation potential of Indian mustard for lead-contaminated soils.