Micro(nano)plastics and terrestrial plants: Up-to-date knowledge on uptake, translocation, and phytotoxicity

Micro(nano)plastics (MNPs) are categorized as emerging persistent pollutants that occur widely in various ecosystems. However, their impacts on terrestrial plants (particularly crops) are poorly understood. Given the persistence and widespread distribution of MNPs in the soil, it is necessary to recognize their potential impacts on terrestrial plants. This paper highlights the uptake, translocation, and phytotoxicity of MNPs in terrestrial plants. Due to their small size and high adsorption capacity, MNPs can adhere to the surfaces of seeds and roots, and thus inhibit seed germination, root elongation, and absorption of water and nutrients, and ultimately inhibit plant growth. Microplastics (MPs), especially nanoplastics (NPs), can be absorbed by roots, and be translocated to stems, leaves, and fruits. The adherence and accumulation of MNPs can induce oxidative stress, cytotoxicity, and genotoxicity in plants, leading to a series of changes in plant growth, mineral nutrition, photosynthesis, toxic accumulation, and metabolites in plants tissues. Overall, the phytotoxicity of MNPs varies dependent on their polymer type, size, dose, and shape, plant tolerance, and exposure conditions. Of particular importance is that the accumulation of MNPs and subsequent damage in plants may further affect crop productivity, and food safety and quality, causing potential health risks. Finally, knowledge gaps and future research priorities are discussed.