Surface coating changes the physiological and biochemical impacts of nano-TiO2 in basil (Ocimum basilicum) plants

Wenjuan Tan; Wenchao Du; Ana C Barrios; Raul Armendariz Jr; Nubia Zuverza-Mena; Zhaoxia Ji; Chong Hyun Chang; Jeffrey I Zink; Jose A Hernandez-Viezcas; Jose R Peralta-Videa; Jorge L Gardea-Torresdey

doi:10.1016/j.envpol.2017.01.002

Surface coating changes the physiological and biochemical impacts of nano-TiO₂ in basil (Ocimum basilicum) plants

Environ Pollut. 2017 Mar:222:64-72. doi: 10.1016/j.envpol.2017.01.002. Epub 2017 Jan 6.

Affiliations

¹ Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States.
² State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China.
³ Chemistry Department, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States.
⁴ Metallurgical and Materials Engineering Department, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States.
⁵ University of California Center for Environmental Implications of Nanotechnology (UC CEIN), California NanoSystems Institute, University of California, Los Angeles, CA, 90095, United States.
⁶ Chemistry Department, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States.
⁷ Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; Chemistry Department, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States.
⁸ Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; Chemistry Department, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, United States. Electronic address: jgardea@utep.edu.

PMID: 28069370
DOI: 10.1016/j.envpol.2017.01.002

Abstract

Little is known about the effects of surface coating on the interaction of engineered nanoparticles (ENPs) with plants. In this study, basil (Ocimum basilicum) was cultivated for 65 days in soil amended with unmodified, hydrophobic (coated with aluminum oxide and dimethicone), and hydrophilic (coated with aluminum oxide and glycerol) titanium dioxide nanoparticles (nano-TiO₂) at 125, 250, 500, and 750 mg nano-TiO₂ kg^-1 soil. ICP-OES/MS, SPAD meter, and UV/Vis spectrometry were used to determine Ti and essential elements in tissues, relative chlorophyll content, carbohydrates, and antioxidant response, respectively. Compared with control, hydrophobic and hydrophilic nano-TiO₂ significantly reduced seed germination by 41% and 59%, respectively, while unmodified and hydrophobic nano-TiO₂ significantly decreased shoot biomass by 31% and 37%, respectively (p ≤ 0.05). Roots exposed to hydrophobic particles at 750 mg kg^-1 had 87% and 40% more Ti than the pristine and hydrophilic nano-TiO₂; however, no differences were found in shoots. The three types of particles affected the homeostasis of essential elements: at 500 mg kg^-¹, unmodified particles increased Cu (104%) and Fe (90%); hydrophilic increased Fe (90%); while hydrophobic increased Mn (339%) but reduced Ca (71%), Cu (58%), and P (40%). However, only hydrophobic particles significantly reduced root elongation by 53%. Unmodified, hydrophobic, and hydrophilic particles significantly reduced total sugar by 39%, 38%, and 66%, respectively, compared with control. Moreover, unmodified particles significantly decreased reducing sugar (34%), while hydrophobic particles significantly reduced starch (35%). Although the three particles affected basil plants, coated particles impacted the most its nutritional quality, since they altered more essential elements, starch, and reducing sugars.

Keywords: Basil; Nutritional value; Surface coating; TiO(2) nanoparticles; Uptake.

Publication types

Comparative Study

MeSH terms

Aluminum Oxide / chemistry
Biological Availability*
Biomass
Dimethylpolysiloxanes / chemistry
Germination / drug effects*
Hydrophobic and Hydrophilic Interactions / drug effects
Nanoparticles
Ocimum basilicum / drug effects*
Ocimum basilicum / growth & development*
Plant Roots / drug effects*
Plant Roots / growth & development
Plant Shoots / drug effects*
Plant Shoots / growth & development
Soil / chemistry
Titanium / analysis
Titanium / chemistry*

Substances

Dimethylpolysiloxanes
Soil
dimethicone
Titanium
Aluminum Oxide