Uptake of Engineered Nanomaterials in Plants and Implication to Food Quality and Safety.

Engineered nanoparticles (NPs) have been widely used in agricultural and food industry. In this study, Au, CuO, CeO₂, TiO₂ NPs, and carbon nanomaterials were used to examine their uptake and accumulation in crops and vegetables. For Au NPs, negatively charged Au NPs were translocated much more than the neutral and positively charged Au NPs in different plant species. CuO NPs not only inhibited the growth and development of corn seedlings, but also were translocated to shoots and leaves via xylem. Agricultural crops (e.g., tomato, soybean) were able to uptake carbon nanotubes (CNTs) and distribute them in different tissues. CuO NPs were also observed in the flowers and harvested seeds of Arabidopsis, confirming the parent-progeny transfer of engineered NPs. These NPs could transfer through some terrestrial food chains. Biomagnification was observed for Au and CeO₂ NPs through tobacco-hornworm, and kidney bean-bean beetle, respectively. C₆₀ facilitated chlordane accumulation in tomato/soybean. However, other ENPs (e.g., CNTs, Ag, TiO₂) suppressed the accumulation of both organic compounds and heavy metals in crops and vegetables. Moreover, NP (e.g., TiO₂, CeO₂) exposures led to significant alternation in contents of proteins and micronutrients in fruits and seeds. All these results have implications for food quality, safety and security.