title: Charge, size, and cellular selectivity for multiwall carbon nanotubes by maize and soybean.
abstract: Maize (Zea mays) and soybean (Glycine max) were used as model food-chain plants to explore vegetative uptake of differently charged multiwall carbon nanotubes (MWCNTs). Three types of MWCNTs, including neutral pristine MWCNT (p-MWCNT), positively charged MWCNT-NH2, and negatively charged MWCNT-COOH, were directly taken-up and translocated from hydroponic solution to roots, stems, and leaves of maize and soybean plants at the MWCNT concentrations ranging from 10.0 to 50.0 mg/L during 18-day exposures. MWCNTs accumulated in the xylem and phloem cells and within specific intracellular sites like the cytoplasm, cell wall, cell membrane, chloroplast, and mitochondria, which was observed by transmission electron microscopy. MWCNTs stimulated the growth of maize and inhibited the growth of soybean at the exposed doses. The cumulative transpiration of water in maize exposed to 50 mg/L of MWCNT-COOHs was almost twice as much as that in the maize control. Dry biomass of maize exposed to MWCNTs was greater than that of maize control. In addition, the uptake and translocation of these MWCNTs clearly exhibited cellular, charge, and size selectivity in maize and soybean, which could be important properties for nanotransporters. This is the first report of cellular, charge, and size selectivity on the uptake by whole food plants for three differently charged MWCNTs.
authors.affiliation: †Department of Civil and Environmental Engineering and IIHR Hydroscience and Engineering, The University of Iowa, Iowa City, Iowa 52242, United States.
authors.forename: Guangshu
authors.initials: G
authors.lastname: Zhai
authors.affiliation: †Department of Civil and Environmental Engineering and IIHR Hydroscience and Engineering, The University of Iowa, Iowa City, Iowa 52242, United States.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Gutowski
authors.affiliation: ‡Central Microscopy Research Facility, The University of Iowa, Iowa City, Iowa 52242, United States.
authors.forename: Katherine S
authors.initials: KS
authors.lastname: Walters
authors.affiliation: §School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Yan
authors.affiliation: †Department of Civil and Environmental Engineering and IIHR Hydroscience and Engineering, The University of Iowa, Iowa City, Iowa 52242, United States.
authors.forename: Jerald L
authors.initials: JL
authors.lastname: Schnoor
mesh_terms: D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D018515:Plant Leaves / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure; D018526:Plant Transpiration / Q000502:physiology; D013025:Glycine max / Q000166:cytology* / Q000254:growth & development / Q000648:ultrastructure; D003313:Zea mays / Q000166:cytology* / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D037742:Nanotubes, Carbon