title: Effects of surface ligands on the uptake and transport of gold nanoparticles in rice and tomato.
abstract: Nanotechnology is advancing rapidly and substantial amounts of nanomaterials are released into the environment. Plants are an essential base component of the ecological environment and play a critical role in the fate and transport of nanomaterials in the environment through plant uptake and bioaccumulation. In this study, plant uptake of gold nanoparticles (GNPs) functionalized with three types of short ligands [cysteamine (CA), cysteine (CYS) and thioglycolic acid (TGA)] and of nearly identical hydrodynamic size (8-12nm) was investigated in the major crops rice (Oryza sativa L.) and tomato (Solanum lycopersicum). Uptake and translocation of GNPs not only depended on particle surface charge, but were also related to the species of ligand on the GNPs. The negatively charged GNPs capped with the CYS ligand (GNP-CYS) were more efficiently absorbed in roots and transferred to shoots (including stems and leaves) than that of GNPs capped with CA and TGA. The absorption process of GNPs involved a combination of both clathrin-dependent and -independent mechanisms. The endocytosis of GNPs was strongly inhibited by wortmannin, suggesting that clathrin-independent endocytosis was an important pathway of nanoparticle internalization in plants. Competition experiments with a free ligand (CYS) showed that the CYS ligand probably facilitated the endocytosis process of GNPs and increased the internalization of GNP-CYS in plants. The results will aid understanding of the mechanisms of nanoparticle uptake and translocation in plants.
authors.affiliation: Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China; Institute of Soil and Fertilizer, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. Electronic address: xxye@issp.ac.cn.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Institute of Soil and Fertilizer, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
authors.forename: Xisheng
authors.initials: X
authors.lastname: Guo
authors.affiliation: Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Geng
authors.affiliation: Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. Electronic address: gzhwang@issp.ac.cn.
authors.forename: Guozhong
authors.initials: G
authors.lastname: Wang
mesh_terms: D003543:Cysteamine / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D006046:Gold / Q000493:pharmacokinetics*; D008024:Ligands; D018551:Solanum lycopersicum / Q000378:metabolism*; D053768:Metal Nanoparticles; D012275:Oryza / Q000378:metabolism*; D013864:Thioglycolates / Q000378:metabolism
chemical_list: D008024:Ligands; D013864:Thioglycolates; D003543:Cysteamine; D006046:Gold; C017487:2-mercaptoacetate; D003545:Cysteine
keywords: Nanoparticle surface functionalization ligand; Rice and tomato; Uptake and translocation; Wortmannin and ikarugamycin inhibitor