Colonization and phytoremediation potential for Miscanthus sacchariflorus in copper tailings

ABSTRACT

A pot experiment was conducted to explore the effects of copper (Cu) tailings with various proportions in the substrate on seed germination and morphological traits of the plant. Concurrently, to identify the adaptive and tolerance strategies of the plant to Cu tailings, the uptake and accumulation of the plant to heavy metals, variations in soil enzymatic activities, and metal speciation in the blank, rhizospheric, and non-rhizospheric soils were estimated. Cu tailings at 25% proportion in the substrate exerted no significant negative effects on seed germination and seedling growth. However, Cu tailings at higher proportions (≧50%) inhibited seed germination and disturbed the plant physiological metabolism and growth. More biomass allocated to the plant roots could contribute to more heavy metals being immobilized, arresting their translocation from roots to shoots. This was accepted as a crucial defense mechanism for the plant against heavy metal co-contamination. The plant can improve the biological properties of Cu tailings in terms of enhanced invertase and phosphatase activities. And in turn, this can effectively alleviate heavy metal phytotoxicity. Simultaneously, it markedly decreased exchangeable Cu and Zn content in the rhizosphere in 25% Cu tailings treatments. In 50% Cu tailings treatment, no differences were observed in Zn speciation between rhizosphere and non-rhizosphere soils. In 75% Cu tailings, compared to the non-rhizosphere, an obvious reduction in exchangeable Cu in rhizosphere occurred, while an opposite tendency was demonstrated in carbonate-bound Zn. The plant could successfully colonize in Cu tailings, and represent a phytoremediation potential in Cu tailings.

GRAPHICAL ABSTRACT

KEYWORDS:

• Copper tailings
• Miscanthus sacchariflorus
• colonization
• phytoremediation
• soil enzyme activity

Acknowledgements

We also thank the Advanced Analysis and Testing Center of Nanjing Forestry University for its kind support during the manuscript preparation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and materials

The datasets used or analysed during the current study are available from the corresponding author on reasonable request.

Authors contributions

Jianpan Xin: The author principally contributed to data analysis and paper writing and modification; Runan Tian: The author have made substantial contributions to the design of the work, revised it critically for crucially intellectual content, and also provide the work with funding assisstance; Yali Liu, Jiefeng Liu: Both the authors devoted themselves to conducting the experiment and collecting the data.

Additional information

Funding

This work was supported by China Postdoctoral Science Foundation [grant number 2020M671509]; National Natural Science Foundation of China [grant number 30972408] and the Priority Academic Program Development of Jiangsu Higher Education Institutions.