title: (1)H NMR and GC-MS Based Metabolomics Reveal Defense and Detoxification Mechanism of Cucumber Plant under Nano-Cu Stress.
abstract: Because copper nanoparticles are being increasingly used in agriculture as pesticides, it is important to assess their potential implications for agriculture. Concerns have been raised about the bioaccumulation of nano-Cu and their toxicity to crop plants. Here, the response of cucumber plants in hydroponic culture at early development stages to two concentrations of nano-Cu (10 and 20 mg/L) was evaluated by proton nuclear magnetic resonance spectroscopy ((1)H NMR) and gas chromatography-mass spectrometry (GC-MS) based metabolomics. Changes in mineral nutrient metabolism induced by nano-Cu were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that nano-Cu at both concentrations interferes with the uptake of a number of micro- and macro-nutrients, such as Na, P, S, Mo, Zn, and Fe. Metabolomics data revealed that nano-Cu at both levels triggered significant metabolic changes in cucumber leaves and root exudates. The root exudate metabolic changes revealed an active defense mechanism against nano-Cu stress: up-regulation of amino acids to sequester/exclude Cu/nano-Cu; down-regulation of citric acid to reduce the mobilization of Cu ions; ascorbic acid up-regulation to combat reactive oxygen species; and up-regulation of phenolic compounds to improve antioxidant system. Thus, we demonstrate that nontargeted (1)H NMR and GC-MS based metabolomics can successfully identify physiological responses induced by nanoparticles. Root exudates metabolomics revealed important detoxification mechanisms.
authors.affiliation: Bren School of Environmental Science and Management, University of California , Santa Barbara, California 93106-5131, United States.|University of California , Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106, United States.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Bren School of Environmental Science and Management, University of California , Santa Barbara, California 93106-5131, United States.|University of California , Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106, United States.
authors.forename: Yuxiong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Materials Research Laboratory, University of California , Santa Barbara, California 93106-5050, United States.
authors.forename: Jerry
authors.initials: J
authors.lastname: Hu
authors.affiliation: Neuroscience Research Institute and Molecular, Cellular and Developmental Biology, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Bren School of Environmental Science and Management, University of California , Santa Barbara, California 93106-5131, United States.|University of California , Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106, United States.
authors.forename: Adeyemi S
authors.initials: AS
authors.lastname: Adeleye
authors.affiliation: Bren School of Environmental Science and Management, University of California , Santa Barbara, California 93106-5131, United States.|University of California , Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106, United States.
authors.forename: Arturo A
authors.initials: AA
authors.lastname: Keller
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D003300:Copper / Q000493:pharmacokinetics / Q000633:toxicity*; D018553:Cucumis sativus / Q000187:drug effects* / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008658:Inactivation, Metabolic; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D055432:Metabolomics / Q000379:methods; D053768:Metal Nanoparticles / Q000633:toxicity; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism
chemical_list: D000596:Amino Acids; D003300:Copper