Date of Graduation

Fall 2015

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Alexander Wait

Keywords

Arabidopsis thaliana, single-walled carbon nanotubes, growth, gas exchange, physiology

Subject Categories

Biology

Abstract

The effect of pure single-walled carbon nanotubes (SWCNTs) on plant growth and gas exchange was investigated in Arabidopsis thaliana. To date there has been no research on the effects of SWCNTs on whole plant physiology. A. thaliana seeds were directly grown in growth medium containing SWCNTs concentrations of 24.93micrograms/ml and 53.55 micrograms/ml. control plants were grown in media containing distilled water. I determined growth by measuring dry mass of plants. I determined gas exchange by measuring photosynthetic rates, stomatal conductance, transpiration rates, and water use efficiency. I also examined the following physiological mechanisms that would limit plant growth: ATP and NADPH supply to light reactions through photosynthetic light response curves, and rubisco activity through photosynthetic CO2 response curves. The presence of SWCNTs in the growth medium had no impact on the whole plant dry weight accumulation in any of the six experimental trials I carried out. Plants grown in growth media containing SWCNTs of a concentration of 24.93 micrograms/ml (4 experimental trials, n=12) and 53.55 micrograms/ml (1 trial, n=3) did not significantly influence any gas exchange variable after 21 days of growth. I also examined gas exchange variables after 7, 14, and 21 days of growth (1 trial, n=3). In this trial, there was a statistically significant treatment and time effect on photosaturated photosynthetic rate, photosynthetic efficiency and water use efficiency. My study illustrates that pure SWCNTs at realistic environmental conditions have no serious negative effects on plant growth and gas exchange; however, they may affect plant developmental rates. These findings have implications for plant and animal health, public awareness, and environmental remediation. KEYWORDS: Arabidopsis thaliana, Single-walled carbon nanotubes, growth, gas exchange, physiology

Copyright

© Rajeeva Voleti

Open Access

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Biology Commons

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