Relatively Low Dosages of CeO 2 Nanoparticles in the Solid Medium Induce Adjustments in the Secondary Metabolism and Ionomic Balance of Bean ( Phaseolus vulgaris L.) Roots and Leaves

Nanoparticles (NPs) are known to significantly alter plant metabolism in a dose-dependent manner, with effects ranging from stimulation to toxicity. The metabolic adjustment and ionomic balance of bean ( L.) roots and leaves gained from plants grown in a solid medium added with relatively low dosages (0, 25, 50, and 100 mg/L) of CeO NPs were investigated. Ce accumulated in the roots (up to 287.91 mg/kg dry weight) and translocated to the aerial parts (up to 2.78% at the highest CeO dosage), and ionomic analysis showed that CeO NPs interfered with potassium, molybdenum, and zinc. Unsupervised hierarchical clustering analysis from metabolomic profiles suggested a dose-dependent and tissue-specific metabolic reprogramming induced by NPs. The majority of differential metabolites belonged to flavonoids and other phenolics, nitrogen-containing low molecules (such as alkaloids and glucosinolates), lipids, and amino acids.