UPTAKE AND TRANSLOCATION OF TI FROM NANOPARTICLES IN CROPS AND WETLAND PLANTS

Abstract

Bioavailability of engineered metal nanoparticles affects uptake in plants, impacts on ecosystems, and phytoremediation. We studied uptake and translocation of Ti in plants when the main source of this metal was TiO₂ nanoparticles. Two crops (Phaseolus vulgaris (bean) and Triticum aestivum (wheat)), a wetland species (Rumex crispus, curly dock), and the floating aquatic plant (Elodea canadensis, Canadian waterweed), were grown in nutrient solutions with TiO₂ nanoparticles (0, 6, 18 mmol Ti L⁻¹ for P. vulgaris, T. aestivum, and R. crispus; and 0 and 12 mmol Ti L⁻¹ for E. canadensis). Also examined in E. canadensis was the influence of TiO₂ nanoparticles upon the uptake of Fe, Mn, and Mg, and the influence of P on Ti uptake. For the rooted plants, exposure to TiO₂ nanoparticles did not affect biomass production, but significantly increased root Ti sorption and uptake. R. crispus showed translocation of Ti into the shoots. E. canadensis also showed significant uptake of Ti, P in the nutrient solution significantly decreased Ti uptake, and the uptake patterns of Mn and Mg were altered. Ti from nano-Ti was bioavailable to plants, thus showing the potential for cycling in ecosystems and for phytoremediation, particularly where water is the main carrier.

KEY WORDS:

• wetland plants
• aquatic plants
• crops
• TiO₂ nanoparticles
• phytoextraction

ACKNOWLEDGMENTS

The authors thank the North Dakota State University Environmental and Conservation Science Graduate Program, the Department of Biological Sciences Frank Cassel Undergraduate Research Awards program, and the Department of Civil Engineering. This project was also supported by grants from the National Center for Research Resources (5P20RR016471-12) and the National Institute of General Medical Sciences (8 P20 GM103442-12) from the National Institutes of Health. Special thanks to Dr. Sharmila Sunwar, Mr. Alex Yellick, and Mr. Ryan Sullivan.