Toxicogenic effects of yttrium oxide nanoparticles on Allium cepa root tip meristem cells

Yttrium is a heavy and emerging rare earth metal, and its effects on organisms have been poorly understood. This study aimed to investigate the cellular changes caused by the metal yttrium in Allium cepa, in order to provide data on its effects on the plant organism. A. cepa seeds were germinated in three concentrations of yttrium oxide: C1 (100 µg/ml), C2 (10 µg/ml), and C3 (1 µg/ml), and ultra-pure water was used as a negative control, while trifluralin at 0.84 mg/l was used as a positive control. The following effects were evaluated: physiological, cytotoxic, and genotoxic. DNA breaks were analyzed using the alkaline precipitation technique and the variation in the number of nucleoli using the AgNOR banding technique. The results obtained were expressed as means and standard deviations, compared with the negative control, and subjected to ANOVA. The cytogenetic tests were subjected to the Tukey test; the Scott-Knott test was used for comparisons of single breaks (p > 0.05). For the data on the number of nucleoli, a generalized linear model (GLM) with a quasipoisson distribution was applied and adjusted by the Tukey test (p < 0.05). The results indicated that yttrium oxide was phytotoxic, genotoxic, and mutagenic depending on its concentration, where C1 indicated a phytotoxic effect, C2 indicated cytotoxic, genotoxic, and mutagenic effects, and C3 indicated a genotoxic effect. In addition, all concentrations caused variation in the number of nucleoli per nucleus. It was concluded that, depending on its concentration, yttrium oxide can induce seed growth and germination and cause damage to the genetic material of the exposed organism, suggesting that the concentrations of these metals should be regulated.