Date of Award
Doctor of Philosophy
Environmental Science and Engineering
The widespread use of copper-based nanomaterials has been accompanied by an increasing interest to understand their potential risks. Due to high surface area to volume properties, nanomaterials are more reactive than their bulk counterparts. Copper nanoparticles are used in numerous products, and could enter the environment through their synThesis or incidental use. It is essential to understand the effects of nanoparticles on edible crops by performing both short-term and long-term experiments at relevant exposure concentrations. In order to evaluate biochemical and physiological effects crops, sugarcane and zucchini, were grown in soil amended with: Kocide 3000 (copper-based fungicide), nano-sized CuO (nCuO), a bulk micron-sized CuO (bCuO), copper nanoparticles (Cu NP), and CuCl2. Briefly, our results show immature sugarcane plants increased their activity of stress enzymes ascorbic peroxidase (APX) and catalase (CAT), at varying concentrations. Concentrations of Cu in roots increased with treatment, with minimal translocation into aerial tissues. Mature sugarcane plants showed no changes in Cu concentrations in root and leaf tissues, but superoxide dismutase activity in sugarcane roots treated with Cu NP and CuCl2 decreased by 55%. Zucchini grown for 3 weeks saw Cu concentrations in root, stem, and leaf tissues increase with rising treatment. APX activity in zucchini roots treated with Kocide, nCuO, and bCuO decreased 45%, while CAT activity in roots treated with Cu NP decreased 77%. Similarly, mature zucchini showed Cu increases in root, leaf, and flower tissues, with all applied treatments. CAT activity in roots increased only in plants treated with Cu NP at 400 mg kg-1. In all studies, plant growth was unaffected by the applied treatments. Based on the results observed, sugarcane and zucchini displayed minimal negative effects upon exposure to copper-base nanoparticles at the tested concentrations.
Received from ProQuest
Tamez, Carlos, "Investigation Into The Effects Of Copper Based Nanoparticles On Sugarcane (saccharum Officinarium) And Zucchini (cucurbita Pepo)" (2019). Open Access Theses & Dissertations. 177.