Effect of metal oxide nanoparticles on amino acids in wheat grains (Triticum aestivum) in a life cycle study.

Engineered nanoparticles (NPs) are now used as additives in pesticides and fungicides and as novel fertilizers in agriculture so there is an urgent need to explore their effects on crop yield and quality in a full life cycle study. In the present study, three widely used NPs (TiO₂, Fe₂O₃ and CuO NPs applied at doses of 50 and 500 mg/kg) were selected to investigate their long-term impact on wheat growth. TiO₂ NPs did not affect the growth and development of wheat, but Fe₂O₃ NPs promoted wheat precocity and CuO NPs inhibited the growth and development of the wheat grains. The Cu content in grains treated with CuO NP increased by 18.84%-30.45% compared with the control. However, the contents of Fe and Zn were both significantly lower in the CuO NP treatments. Univariate and multivariate analyses were used to analyze the effect of different NPs on the composition of amino acids in wheat grains. Exposure to TiO₂ NPs at dose of 500 mg/kg increased the overall amino acid nutrition in the edible portion of wheat. Fe₂O₃ NPs at both doses increased the contents of cysteine (Cys) and tyrosine (Tyr). The addition of CuO NPs reduced the level of some essential amino acids in wheat grains, isoleucine (Ile), leucine (Leu), threonine (Thr) and histidine (His). Overall, evaluation of the potential impacts of metal-based NPs on the nutritional quality of wheat grains could provide important information for their safe use when incorporated into agrichemicals in sustainable agriculture.