Minimal Transgenerational Effect of ZnO Nanomaterials on the Physiology and Nutrient Profile of Phaseolus vulgaris

Bean (Phaseolus vulgaris) plants were cultivated in nanoparticle-unamended soil, and their second-generation seeds (S2) were analyzed to determine the transgenerational effects of uncoated nano-ZnO (Z-COTE), coated nano-ZnO (Z-COTE HP1), bulk ZnO, or ionic Zn (ZnCl₂) at 0–500 mg kg^–1. Antioxidant enzymatic activity was determined in immature seeds, while the yield and nutritional composition of the seeds were measured at the end of the growth cycle. None of the treatments affected seed production, maturation time, Zn accumulation, or the content of sugar, starch, or protein in S2, compared with controls. The accumulation of K, P, S, Mg, Fe, Mn, B, Mo, and Cu in S2 seeds also remained unaffected. However, Z-COTE at 500 mg kg^–1 and Z-COTE HP1 at 125 and 500 mg kg^–1 reduced Ni in S2 seeds by 60%, 41%, and 74%, respectively, compared with the control. The Zn nanomaterials (NMs) did not impact the activity of ascorbate peroxidase, catalase, and superoxide dismutase (SOD) in the seeds. However, ZnCl₂ at 500 mg kg^–1 increased SOD by 28% in S2 seeds. The data suggest that ZnO NMs have low residual transgenerational effects on seed composition, which could be beneficial in agricultural production.