Effect of surface coating and organic matter on the uptake of CeO2 NPs by corn plants grown in soil: Insight into the uptake mechanism.
Little is known about the fate, transport, and bioavailability of CeO(2) nanoparticles (NPs) in soil. Moreover, there are no reports on the effect of surface coating upon NPs uptake by plants. In this study, Zea mays plants were grown for one month in unenriched and organic soils treated with coated and uncoated CeO(2) NPs. In addition, plants were exposed to fluorescein isothiocyanate (FITC)-stained CeO(2) NPs and analyzed in a confocal microscope. In organic soil, roots from uncoated and coated NPs at 100, 200, 400, and 800mg kg(-1) had 40, 80, 130, and 260% and 10, 70, 90, and 40% more Ce, respectively, compared to roots from unenriched soil. Conversely, shoots of plants from unenriched soil had significantly more Ce compared with shoots from organic soil. Confocal fluorescence images showed FITC-stained CeO(2) NP aggregates in cell walls of epidermis and cortex, suggesting apoplastic pathway. The μXRF results revealed the presence of CeO(2) NP aggregates within vascular tissues. To the authors knowledge this is the first report on the effects of surface coating and organic matter on Ce uptake from CeO(2) NPs and upon the mechanisms of CeO(2) NPs uptake by higher plants.
Chemistry Department, The University of Texas at El Paso, 500 West Univ. Av., El Paso, TX 79968, USA.
Lijuan
L
Zhao
Jose R
JR
Peralta-Videa
Armando
A
Varela-Ramirez
Hiram
H
Castillo-Michel
Chunqiang
C
Li
Jianying
J
Zhang
Renato J
RJ
Aguilera
Arturo A
AA
Keller
Jorge L
JL
Gardea-Torresdey
D000464:Alginates / Q000737:chemistry* / Q000378:metabolism; D002563:Cerium / Q000737:chemistry / Q000378:metabolism*; D020723:Glucuronic Acid / Q000737:chemistry / Q000378:metabolism; D006603:Hexuronic Acids / Q000737:chemistry / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D013499:Surface Properties; D056928:X-Ray Absorption Spectroscopy; D003313:Zea mays / Q000378:metabolism*
D000464:Alginates; D006603:Hexuronic Acids; D012987:Soil; D012989:Soil Pollutants; D002563:Cerium; C030583:ceric oxide; D020723:Glucuronic Acid