Session: General Poster:

The effect of surface-functionalized nanomaterials (NMs) on the development of agricultural plants, especially the belowground root crops, has attracted increased interest. After release, NMs may remain in the soil for an extended period and undergo significant transformation reactions. In this study, carrots (Daucus carota L.) were grown in soils amended with titanium dioxide nanoparticles (nTiO₂, pristine, hydrophilic- or hydrophobic-surface coated) at 100, 200, and 400 mg/kg until full-plant maturity. To investigate the aging effect, nanoparticles were weathered in native soil for four months before the cultivation of plants. In carrots treated by the freshly exposed nTiO₂, the taproot fresh biomass was significantly decreased by all nTiO₂ forms at 400 mg/kg compared with control. An abnormal increase of taproot splitting was found. The accumulation of Mg, Mn, and Zn in the taproot was decreased. However, after the aging process, all the negative impacts listed above were alleviated, both in a surface coating and concentration dependent-manner. The aged surface-coated nTiO2 improved taproot and leaf fresh biomass and plant height compared to control. The Fe in leaves, Mg in taproots, and Ca, Zn, and K in roots were enhanced by exposure to the aged nTiO2. These results may contribute to the development of safe and sustainable applications of nTiO₂ in nano-enabled agriculture.

Jorge Gardea-Torresdey

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