Uptake, Translocation, and Transmission of Carbon Nanomaterials in Rice Plants
Uptake, Translocation, and Transmission of Carbon Nanomaterials in Rice Plants
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DOI：
10.1002/smll.200801556
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发表时间：
2009-05-18
期刊：
影响因子：
13.3
通讯作者：
Ke, Pu Chun
中科院分区：
文献类型：
--
作者：
Lin, Sijie;Reppert, Jason;Ke, Pu Chun
Recent development of nanotechnology has reshaped the landscape of modern science and technology, while in the meantime raised concerns about the adverse effects of nanomaterials on biological systems and the environment.[1, 2] Owing to their mutual interaction, carbon-based nanomaterials readily aggregate and are not considered potential contaminants in the liquid phase.[3] However, when discharged into the environment, the hydrophobicity of nanomaterials can be averted through their interaction with natural organic matter (NOM),[4] a heterogeneous mixture of decomposed animals and plants and a major pollutant carrier [5] in nature. Consequently, mobile NOM-modified nanomaterials may pose a threat to ecological terrestrial species through further physical, chemical, and biological processes. The impact of nanomaterials on high plants has scantly been examined in the current literature. Among the studies available,[6–12] none have used major food crops or carbon nanoparticles (a major class of nanomaterials) for their evaluations. Although both enhanced and inhibited growth have been reported for vegetations exposed to nanomaterials at various developmental stages,[6–12] including seed germination, root growth, and photosynthesis, fundamental questions remain regarding the uptake, accumulation, translocation, and transmission of nanomaterials in plant cells and tissues, and the impact of these processes on plant reproduction.[13] Here, we provide the first evidence on the uptake, accumulation, and generational transmission of NOM-suspended carbon nanoparticles in rice plants, the staple food crops of over half the world’s population. The data presented in this Communication suggest the potential impact of nanomaterial exposure on plant development and the food chain, and prompt further investigation into the genetic consequences through plant–nanomaterial interactions.NOM in freshwater ecosystems ususally has a concentration between 1–100mg LÀ1.[14] To mimic the natural ecosystems we formed a NOM solution of 100mg LÀ1 in Milli-Q water and suspended fullerene C70 and multiwalled carbon nanotubes (MWNTs) in the NOM. Using a Zetasizer (S90, Malvern Instruments) we identified three hydrodynamic diameters of 1.19 (major), 17.99, and 722.10 nm for C70–NOM and one major hydrodynamic diameter of 239.70 nm for MWNT–NOM (see Supporting Information, Sections 1C and 1D). The nonspecific assembly of NOM with C70 or MWNTs is believed to be a dynamic equilibrium process [4] with the hydrophobic moieties of the NOM interacting and p-stacking with the hydrophobic carbon nanoparticle surfaces. Newly harvested rice seeds were incubated in Petri dishes that contained 15 mL of different concentrations of C70–NOM and MWNT–NOM in rice germination buffer. After germination at 25Æ 1 8C for 2 weeks the seedlings were transplanted to soil in big pots and grown in a green house to maturity without addition of nanoparticles. For each sample concentration, 5 pots of plants were maintained for analysis. These plants are referred to as the first generation. The plants grown in the germination buffer are known as the control. Identical amounts of NOM were used for C70–NOM and MWNT–NOM for each concentration. For example, the NOM concentration in ‘‘NOM400’’was identical to that in C70–NOM or MWNT–NOM of 400 mg LÀ1. To investigate generational transmission of nanomaterials, mature seeds from the control plants and C70-treated plants were harvested 6 months after germination, and 60 seeds of similar size for each plant were chosen and sterilized using the same method as …
