Advances in transport and toxicity of nanoparticles in plants

Abstract

In recent years, the rapid development of nanotechnology has made significant impacts on the industry. With the wide application of nanotechnology, nanoparticles (NPs) are inevitably released into the environment, and their fate, behavior and toxicity are indeterminate. Studies have indicated that NPs can be absorbed, transported and accumulated by terrestrial plants. The presence of NPs in certain edible plants may decrease harvests and threaten human health. Understanding the transport and toxicity of NPs in plants is the basis for risk assessment. In this review, we summarize the transportation of four types of NPs in terrestrial plants, and the phytotoxicity induced by NPs, including their impacts on plant growth and cell structure, and the underlying mechanisms such as inducing oxidative stress response, and causing genotoxic damage. We expect to provide reference for future research on the effects of NPs on plants.

Keywords: Absorb; Nanoparticles; Phytotoxicity; Plants; Transport.

Fig. 1

Characterization of NPs. a Metal NPs: 10 nm silver NPs [22]; (b) Metal oxide NPs: 79.6 ± 5 nm zinc oxide NPs [40]; (c) Carbon-based NPs: 2 nm CDs [41]; (d) 100 nm PS-NPs [42]. CDs carbon dots, PS-NPs polystyrene nanoplastics

Fig. 2

Transport and distribution of NPs in plants. a TEM image of Ag NPs in onion cells. Red arrows indicate NPs and blue arrows indicate microtubules [43]; (b) EDX mapping of wheat cells exposed to CuO NPs [19]; (c–d) Localization of GNS in leaves of eggplant and pepper (C elliptic chloroplasts, CW cell wall, GC giant chloroplasts, GS giant starch grains) [46]; (e) Transverse (upper) and longitudinal (lower) confocal images of rice roots exposed to plastic NPs [47]. TEM transmission electron microscopy, EDX energy-dispersive X-ray spectroscopy, GNS graphene nanosheets

Fig. 3

Absorption and transportation mechanism of NPs in plants. a NPs are absorbed by stomatal, and transfer from leaves and stems to roots; (b) NPs transfer through apoplast pathway; (c) NPs enter and transport by xylem and phloem, and transfer from roots to leaves or stems; (d) NPs transport through diffusion, endocytosis, and carrier proteins and channels. The red dots represent NPs

Fig. 4

Effects of NPs exposure on plants. a Exposure of Fe NPs promoted the growth of pepper seedlings [78]; b Plastic NPs exposure inhibited the root elongation of wheat seedlings [81]; (c) Exposure of Al₂O₃ destroyed the plasma membrane structure of soybean roots (PM plasma membrane, CW cell wall, ML middle lamella, GC Golgi complex, M mitochondria) [82]; (d) The internalization of Ag NPs increased the level of ROS in Vicia faba leaves [83]; (e) Ag NPs induced chromosome aberration in wheat root tip cells [84]; f, Plastic NPs exposure stimulated the transcriptomics response of rice [57]

Fig. 5

Mechanism of phytotoxicity induced by NPs. CAT catalase; DSBs double strand breaks, MDA malondialdehyde, ROS reactive oxygen, SOD superoxide dismutase, SSBs single-strand breaks. The red dots represent NPs