Application of metabolomics to assess the impact of Cu(OH)(2) nanopesticide on the nutritional value of lettuce (Lactuca sativa): Enhanced Cu intake and reduced antioxidants

作者：Zhao, Lijuan; Huang, Yuxiong; Hannah-Bick, Cameron; Fulton, Aaron N.; Keller, Arturo A.^*

来源：NanoImpact, 2016, 3-4: 58-66.

DOI：10.1016/j.impact.2016.08.005

• COPPER NANOPARTICLES
• POLYAMINES
• PLANTS
• QUALITY
• FRUIT
• DISSOLUTION
• METABOLISM
• TOXICITY
• CAPACITY
• EXPOSURE

Copper-based nanopesticides are increasingly being used in the agriculture, especially in organic farming. This has triggered some concerns about their risk to environmental and human health. In this study, 24-day-old lettuce plants grown in soil were exposed via the leaves to different concentrations (0, 1050 and 1555 mg/L) of Cu(OH)(2) nanopesticides for one month. Results showed Cu was mainly localized in lettuce leaves (823-1111 and 1353-2008 mg/kg in vascular and photosynthetic tissues), which may potentially increase Cu intake and impact human health. In addition, foliar application of Cu(OH)(2) nanopesticide significantly increased potassium concentration in lettuce leaves by 6-7% and 21-28%, in vascular and photosynthetic tissues. A Gas Chromatography-Time-of-Flight Mass Spectrometry (GC-TOF-MS) based metabolomics approach was applied to determine hundreds of organic compounds simultaneously. Using relative quantitation and Partial Least Squares-Discriminant Analysis (PLS-DA) clustering of all compounds, clear differences were observed in the metabolite profiles of control and Cu(OH)(2) nanopesticides treated leaves. Discriminating compounds include amino acids, organic acids, polyamines, vitamin C and polyphenols. Dehydroascorbic acid and cis-caffeic acid, which are important antioxidants, were significantly decreased (19-33% and 5-8%) due to foliar exposure to the nanopesticide. Total antioxidant capacity was significantly decreased 20-23% after exposure to Cu(OH)(2) nanopesticides. There was also up-and down-regulation of a number of amino acids, particularly 4-hydroxybutytic acid (GABA) which decreased 50% compared to the control, potentially affecting the overall nutritional value of lettuce leaves exposed to the Cu(OH)(2) nanopesticides. In future work, determining an appropriate level of nanopesticide will be important to obtain the antifungal benefits without resulting in a significant decrease in nutritional value.

• 出版日期2016-7