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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #336798
Title: Copper oxide nanoparticle effects on root growth and hydraulic conductivity of two vegetable crops

Author
item MARGENOT, ANDREW - University Of California
item RIPPNER, DEVIN - University Of California
item DUMLAO, MATT - University Of California
item NEZAMI, SAREH - University Of California
item GREEN, PETER - University Of California, Davis
item PARIKH, SANJAI - University Of California
item McElrone, Andrew

Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2018
Publication Date: 10/1/2018
Citation: Margenot, A., Rippner, D., Dumlao, M., Nezami, S., Green, P.G., Parikh, S., McElrone, A.J. 2018. Copper oxide nanoparticle effects on root growth and hydraulic conductivity of two vegetable crops. Plant and Soil. 431(1-2):333-345. https://doi.org/10.1007/s11104-018-3741-3.
DOI: https://doi.org/10.1007/s11104-018-3741-3

Interpretive Summary: Aims: Root growth and water transport were evaluated for two vegetable crops of contrasting root architecture (lettuce, carrot) exposed to copper oxide nanoparticles (CuO NPs). Methods: 10-day seedling root growth assays were evaluated for 16 nanometer (nm) diameter CuO NP and CuCl 2control (0.8 – 798.9 mg Cu L -1). In a separate experiment, hydraulic conductivity (K h) of root systems not previously exposed to NP was tested using 16 and 45 nm CuO NP (798.9 mg Cu L -1) relative to CuO NP-free controls, and xylem sap was assessed by TEM-EDS for presence of CuO NPs. Results: 16 nm CuO NP produced dose-dependent increases in root diameter for lettuce (+52%) and carrot (+26%) seedlings, whereas CuCl 2did not affect (lettuce) or marginally increased (carrot) root diameter. Root K hwas similarly reduced by 16 and 45 nm CuO NPs for lettuce (-46%) but not for carrot, and no Cu was identified by TEM-EDS in xylem sap. Conclusions: Adverse effects of CuO NPs on root physiology and function in the early stages of growth of two key food crops are not necessarily due to Cu 2+toxicity and can be specific to crop species. In addition to triggering root thickening, reduction of root K hsignifies that CuO NPs can compromise root water transport and thus crop performance.

Technical Abstract: Aims Root growth and water transport were evaluated for two vegetable crops of contrasting root architecture (lettuce, carrot) exposed to copper oxide nanoparticles (CuO NPs). Methods 10-day seedling root growth assays were evaluated for 16 nanometer (nm) diameter CuO NP and CuCl2 control (0.8 – 798.9 mg Cu L'¹). In a separate experiment, hydraulic conductivity (Kh) of root systems not previously exposed to NP was tested using 16 and 45 nm CuO NP (798.9 mg Cu L'¹) relative to CuO NP-free controls, and xylem sap was assessed by TEM-EDS for presence of CuO NPs. Results 16 nm CuO NP produced dose-dependent increases in root diameter for lettuce (+52%) and carrot (+26%) seedlings, whereas CuCl2 did not affect (lettuce) or marginally increased (carrot) root diameter. Root Kh was similarly reduced by 16 and 45 nm CuO NPs for lettuce (-46%) but not for carrot, and no Cu was identified by TEM-EDS in xylem sap. Conclusions Adverse effects of CuO NPs on root physiology and function in the early stages of growth of two key food crops are not necessarily due to Cu²' toxicity and can be specific to crop species. In addition to triggering root thickening, reduction of root Kh signifies that CuO NPs can compromise root water transport and thus crop performance.