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United States Department of Agriculture

Agricultural Research Service

Research Project: CHARACTERIZATION AND ENHANCEMENT OF PLANT RESISTANCE TO WATER-DEFICIT AND THERMAL STRESSES Title: The Effects of Multi-walled Carbon Nanotubes on the Physiology, Morphology, and Rhizoshpere Microbial Community of Medicago Sative and Pteris Vittata.

Authors
item Shrestha, Babina -
item Canas, Jaclyn -
item Payton, Paxton
item Acosta-Martinez, Veronica

Submitted to: Journal of Society of Environmental Toxicology and Chemistry
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2010
Publication Date: N/A

Technical Abstract: Applications of nanomaterials are increasing due to their noble physical structures. Carbon nanotubes (CNTs) are one of the most widely used carbon nanomaterial at present, however the fate, transport and toxicity of CNTs is still not well understood. Potential concern has been raised regarding future effects on the environment, humans, animals as well as plants. Due to CNTs capacities to adsorb organic and inorganic contaminants and their ability to penetrate the plant cell wall, their potential use in phytoremediation of inorganic and organic contaminants has been proposed. However, considering very few studies have been conducted on the phytotoxicity of carbon nanotubes, it is important to assess the toxicity of CNTs on plants and soil microbial communities. Both plant and soil rhizosphere microbial communities have important roles in phytoremediation. In this study, preliminary experiments will be conducted to determine an appropriate CNTs soil concentration range to be used in a planned future phytoremediation study as well as to understand the potential toxicity of CNTs on plant and soil rhizosphere microbial communities. This study will investigate the effects of the presence of multi-walled carbon nanotubes (MWNTs) on plant (Medicago sativa and Pteris vittata) physiology, morphology and soil rhizosphere microbial community. Medicago sativa (Alfalfa plant) and Pteris vittata (Chinese Brake Fern) are most widely used and studied for phytoremediation of PAHs and PCBs, and arsenic respectively. Plants will be grown in a control soil and in soil spiked with MWNTs at six different concentrations (5, 10, 25, 50, 100 and 200 mg/kg). The study will be conducted for three months during which shoot and root growth, water uptake, transpiration and photosynthesis rate will be monitored. Also the uptake and distribution of MWNTs within different parts of the plants will be monitored at the end of study period. Soil rhizosphere microbial biomass, composition and activity will also be measured. The results at different concentrations of MWNTs will be compared to each other and the control to determine if there are significant differences in plant physiology, morphology and soil rhizosphere microbial community due to presence of MWNTs in soil. The study results will provide information on potential toxicity of carbon nanotubes on the plants and rhizosphere microbial communities. This data will be valuable for risk assessment and evaluation of nanomaterials.

Last Modified: 10/22/2014
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