Most microplastics are emitted, either directly or via the degradation of plastics, to the terrestrial environment and accumulate in large amounts in soils, representing a potential threat to terrestrial ecosystems. It is very important to evaluate the uptake of microplastics by crop plants because of the ubiquity of microplastics in wastewaters often used for agricultural irrigation worldwide. Here, we analyse the uptake of different microplastics by crop plants (wheat (Triticum aestivum) and lettuce (Lactuca sativa)) from treated wastewater in hydroponic cultures and in sand matrices or a sandy soil. Our results provide evidence in support of submicrometre- and micrometre-sized polystyrene and polymethylmethacrylate particles penetrating the stele of both species using the crack-entry mode at sites of lateral root emergence. This crack-entry pathway and features of the polymeric particles lead to the efficient uptake of submicrometre plastic. The plastic particles were subsequently transported from the roots to the shoots. Higher transpiration rates enhanced the uptake of plastic particles, showing that the transpirational pull was the main driving force of their movement. Our findings shed light on the modes of plastic particle interaction with plants and have implications for crops grown in fields contaminated with wastewater treatment discharges or sewage sludges.
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The data that support the findings of this study are available in the paper and its Supplementary Information or from the corresponding author upon request.
Jambeck, J. R. et al. Plastic waste inputs from land into the ocean. Science 347, 768–771 (2015).
Barnes, D. K. A. et al. Accumulation and fragmentation of plastic debris in global environments. Phil. Trans. R. Soc. B 364, 1985–1998 (2009).
Wallace, H. Presence of microplastics and nanoplastics in food, with particular focus on seafood. EFSA J. 14, e04501 (2016).
Wardrop, P. et al. Chemical pollutants sorbed to ingested microbeads from personal care products accumulate in fish. Environ. Sci. Technol. 50, 4037–4044 (2016).
Rochman, C. M. Microplastics research-from sink to source. Science 360, 28–29 (2018).
Seltenrich, N. New link in the food chain? marine plastic pollution and seafood safety. Environ. Health Persp. 123, A34-41 (2015).
Nizzetto, L., Langaas, S. & Futter, M. Pollution: do microplastics spill on to farm soils? Nature 537, 488 (2016).
Zhou, Q. et al. The distribution and morphology of microplastics in coastal soils adjacent to the Bohai Sea and the Yellow Sea. Geoderma 322, 201–208 (2018).
Weithmann, N. et al. Organic fertilizer as a vehicle for the entry of microplastic into the environment. Sci. Adv. 4, EAAP8060 (2018).
Nizzetto, L., Futter, M. & Langaas, S. Are agricultural soils dumps for microplastics of urban origin? Environ. Sci. Technol. 50, 10777–10779 (2016).
van Sebille, E. A global inventory of small floating plastic debris. Environ. Res. Lett. 10, 124006 (2015).
Rodriguez-Seijo, A. et al. Histopathological and molecular effects of microplastics in Eisenia andrei Bouché. Environ. Pollut. 220, 495–503 (2017).
Huerta Lwanga, E. et al. Field evidence for transfer of plastic debris along a terrestrial food chain. Sci. Rep. 7, 14071 (2017).
Sato, T. et al. Global, regional, and country level need for data on wastewater generation, treatment, and use. Agric. Water Manage. 130, 1–13 (2013).
Kalčíková, G. et al. Wastewater treatment plant effluents as source of cosmetic polyethylene microbeads to freshwater. Chemosphere 188, 25–31 (2017).
Schwab, F. et al. Barriers, pathways and processes for uptake, translocation and accumulation of nanomaterials in plants - critical review. Nanotoxicology 10, 257–278 (2016).
Robardsa, W. & Jackson, M. in Perspectives in Experimental Biology Vol. 2 (ed. Sunderland, N.) 413–422 (Pergamon, 1976).
Karas, I. & Mccully, M. E. Further studies of the histology of lateral root development in Zea mays. Protoplasma 77, 243–269 (1973).
Huang, J. Ultrastructure of bacterial penetration in plants. Annu. Rev. Phytopathol. 24, 141–157 (1986).
Vega-Hernández, M. C. et al. Novel infection process in the indeterminate root nodule symbiosis between Chamaecytisus proliferus (tagasaste) and Bradyrhizobium sp. New Phytol. 150, 707–721 (2001).
Marschner, H. Mineral Nutrition of Higher Plants 2nd edn (Academic, 1995).
Carpita, N. et al. Determination of the pore size of cell walls of living plant cells. Science 205, 1144–1147 (1979).
Smith, H. The Molecular Biology of Plant Cells (Univ. of California Press, 1978).
Enstone, D. E. & Peterson, C. A. Suberin lamella development in maize seedling roots grown in aerated and stagnant conditions. Plant Cell Environ. 28, 444–455 (2005).
Gouin, T. et al. Use of micro-plastics beads in cosmetics products in Europe and their estimated emissions to the North Sea environment. SOFW J. 141, 40–46 (2015).
Plastic in Cosmetics (UNEP, 2015).
Fendall, L. S. & Sewell, M. A. Contributing to marine pollution by washing your face: microplastics in facial cleansers. Mar. Pollut. Bull. 58, 1225–1228 (2009).
Fahn, A. Plant Anatomy (Pergamon, 1982).
Ristroph, K. D. et al. Zein nanoparticles uptake by hydroponically grown soybean plants. Environ. Sci. Technol. 51, 14065–14071 (2017).
González-Melendi, P. et al. Nanoparticles as smart treatment-delivery systems in plants: assessment of different techniques of microscopy for their visualization in plant tissues. Ann. Bot. 101, 187–195 (2008).
Taylor, A. F. et al. Investigating the toxicity, uptake, nanoparticle formation and genetic response of plants to gold. PLoS ONE 9, e93793 (2014).
Larue, C. et al. Accumulation, translocation and impact of TiO2 nanoparticles in wheat (Triticum aestivum spp.): influence of diameter and crystal phase. Sci. Total Environ. 431, 197–208 (2012).
Zhang, M. & Akbulut, M. Adsorption, desorption, and removal of polymeric nanomedicine on and from cellulose surfaces: effect of size. Langmuir 27, 12550–12559 (2011).
Wen, F. et al. Extracellular proteins in pea root tip and border cell exudates. Plant Physiol. 143, 773–783 (2007).
Driouich, A. et al. Root border cells and secretions as critical elements in plant host defense. Curr. Opin. Plant Biol. 16, 489–495 (2013).
Nel, A. E. et al. Understanding biophysicochemical interactions at the nano-bio interface. Nat. Mater. 8, 543–557 (2009).
Wang, C. X. et al. Modelling the mechanical properties of single suspension-cultured tomato cells. Ann. Bot. 93, 443–453 (2004).
Yu, M. et al. Rapid transport of deformation-tuned nanoparticles across biological hydrogels and cellular barriers. Nat. Commun. 9, 2607 (2018).
Li, L. Z. et al. Uptake and accumulation of microplastics in an edible plant. Chin. Sci. Bull. 64, 928–934 (2019).
White, P. J. Long-Distance Transport in the Xylem and Phloem (Elsevier, 2011).
Production/Crops (FAO Statistics Division, 2017); http://faostat3.fao.org/browse/Q/QC/E.
GEMS/Food Regional Diets: Regional Per Capita Consumption of Raw and Semi-processed Agricultural Commodities (WHO, 2003).
Lehner, R. et al. Emergence of nanoplastic in the environment and possible impact on human health. Environ. Sci. Technol. 53, 1748–1765 (2019).
Ter Halle, A. et al. Nanoplastic in the North Atlantic subtropical gyre. Environ. Sci. Technol. 51, 13689–13697 (2017).
Lambert, S. & Wagner, M. Characterisation of nanoplastics during the degradation of polystyrene. Chemosphere 145, 265–268 (2016).
Mitrano, D. M. et al. Synthesis of metal-doped nanoplastics and their utility to investigate fate and behaviour in complex environmental systems. Nat. Nanotechnol. 14, 362–368 (2019).
Zubris, K. A. V. & Richards, B. K. Synthetic fibers as an indicator of land application of sludge. Environ. Pollut. 138, 201–211 (2005).
Lu, S., Qu, R. & Forcada, J. Preparation of magnetic polymeric composite nanoparticles by seeded emulsion polymerization. Mater. Lett. 63, 770–772 (2009).
Peng, B. et al. Synthesis of monodisperse, highly cross-linked, fluorescent PMMA particles by dispersion polymerization. Langmuir 28, 6776–6785 (2012).
Hoagland, D. R. & Arnon, D. I. The Water-Culture Method for Growing Plants without Soil Circular No. 347 (Univ. of California, College of Agriculture, 1938).
Jiao, L. et al. Improving the brightness and photostability of NIR fluorescent silica nanoparticles through rational fine-tuning of the covalent encapsulation methods. J. Mater. Chem. B 5, 5278–5283 (2017).
Stanghellini, C. & Van Meurs, W. T. M. Environmental control of greenhouse crop transpiration. J. Agric. Eng. Res. 51, 297–311 (1992).
We acknowledge the financial support by the National Nature Science Foundation of China (grant nos 41877142 and 41991330), the Key Research Program of Frontier Sciences, CAS (grant no. QYZDJ-SSW-DQC015) and the External Cooperation Program of BIC, Chinese Academy of Sciences (grant no. 133337KYSB20160003). We thank P. Christie from the Institute of Soil Science, Chinese Academy of Sciences, China, for contributing to language polishing.
The authors declare no competing interests.
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Li, L., Luo, Y., Li, R. et al. Effective uptake of submicrometre plastics by crop plants via a crack-entry mode. Nat Sustain (2020). https://doi.org/10.1038/s41893-020-0567-9
Nature Sustainability (2020)