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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #336798

Research Project: Sustainable Vineyard Production Systems

Location: Crops Pathology and Genetics Research

Title: Copper oxide nanoparticle effects on germination, root physiology and hydraulic conductivity of two food crop species

Author
item Margenot, Andrew - University Of California
item Parikh, Sanjai - University Of California
item Dumlao, Matt - University Of California
item Rippner, Devin - University Of California
item Nezami, Sareh - University Of California
item Silk, Wendy - University Of California
item Mcelrone, Andrew

Submitted to: Environmental Science: Nano
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Engineered nanoparticles (NPs) have potential to adversely impact the growth of food crops. We investigated the short-term response of root growth and function to copper oxide (CuO) NP exposure using two food crop species of contrasting root architecture and edible tissues, lettuce (Lactuca sativa) and carrot (Daucus carota subsp. sativus). Lettuce and carrot germination and root length and diameter were assessed after 10-day exposure to CuO NP (16 nm diameter). Dissolution of CuO NPs and the use of a Cu2+ control were used to distinguish Cu2+ toxicity from nano-size effects. In a separate experiment, root hydraulic conductivity (Kh) was assessed for lettuce and carrot seedlings during acute CuO NP exposure. During germination and root growth assays, CuO NP (16 nm diameter; 0.8 – 799 mg Cu L-1) underwent dissolution inverse to concentration (5-46%), and yielded Cu2+ concentrations of 0.6 – 66.8 mg L-1, which was similar to the CuCl2 control of 0.05 – 47.3 mg Cu L-1. Lettuce and carrot germination was not affected by CuO NP, but CuCl2 decreased germination at concentrations = 4.7 mg Cu L-1 by up to 50% for lettuce and 86% for carrot despite similar Cu2+ concentrations in CuO NP treatments. Root length was more reduced by CuCl2 than CuO NP. CuO NP produced dose-dependent increases in root diameter for lettuce (+52% diameter) and carrot (+26%), whereas CuCl2 did not affect (lettuce) or marginally increased (carrot) root diameter. Root Kh was similarly reduced by 16 and 45 nm diameter CuO NPs (799 mg Cu L-1) for lettuce (-46%) but not for carrot. No CuO NP or Cu species were identified by TEM-EDS in xylem sap during conductivity measurements. These results demonstrate adverse effects of CuO NPs on root physiology and function in the early stages of growth of two key food crops not mediated by Cu2+ toxicity.