Lead bioaccumulation, subcellular distribution and chemical form in sugarcane and its potential for phytoremediation of lead-contaminated soil

Abstract

Sugarcane is a promising species for lead (Pb) phytoextraction due to its large biomass and high tolerance toward Pb content. To understand the mechanisms involved in Pb tolerance and detoxification and its potential for phytoremediation in sugarcane, the bioaccumulation, subcellular distribution, and chemical forms of Pb in different tissues were investigated through pot cultivation sugarcane with increasing Pb concentrations in the present study. Results showed that sugarcane could tolerate high concentrations of Pb (up to 1250.0–1750.0 mg/kg); the Pb content in roots and shoots increased with increasing Pb concentration. A large amount of Pb content was stored in roots. The subcellular distribution of Pb in sugarcane revealed that the majority of Pb was bound to the cell wall. Meanwhile, the greatest amount of Pb was extracted by 2.0% acetic acid and 0.6 mol/L HCl, which indicated that most of Pb was combined with undissolved phosphate and oxalate. These results implied that the Pb formation of undissolved salts and compartmentalization in the cell wall may be a key strategy for Pb detoxicity and tolerance in sugarcane.

Keywords:

• chemical form
• lead
• sugarcane
• subcellular distribution

Additional information

Funding

This work was supported by the Guangxi Natural Science Foundation (Grant No. 2015GXNSFEA139001) from the Guangxi science and Technology Department, the project of International Scientific Exchange Program (grant No. 7-1, 2017) from the Ministry of Science and Technology of the People’s Republic of China, Guangxi Major Projects of Science and Technology (Grant No. GXMPSTAA17202032).