Physiological and Biochemical Changes Imposed by CeO2 Nanoparticles on Wheat: A Life Cycle Field Study

Area of Science:

• Environmental Science
• Plant Biology
• Nanotechnology

Background:

• Plant interactions with nanomaterials are often studied under controlled conditions and at early growth stages.
• Understanding the long-term effects of nanomaterials like nano-ceria (nCeO2) on crop plants throughout their entire lifecycle is crucial for agricultural applications.

Purpose of the Study:

• To evaluate the effects of different concentrations of nano-ceria (nCeO2) on wheat plants over their complete lifecycle under field lysimeter conditions.
• To assess impacts on physiological parameters, cellular structure, yield, and grain composition.

Main Methods:

• Wheat plants were grown in a field lysimeter and treated with 0 (control), 100 (low), and 400 (high) mg/kg of nCeO2.
• Measurements included chlorophyll content, enzyme activities (catalase, superoxide dismutase), cell microstructure, flowering time, starch grain size, biomass, yield, shoot cerium concentration, and grain composition (sugar, starch, protein).

Main Results:

• High nCeO2 concentration decreased chlorophyll content and increased antioxidant enzyme activities (catalase, superoxide dismutase).
• Both low and high nCeO2 concentrations altered root and leaf cell microstructures, delayed flowering, and reduced starch grain size.
• While final biomass, yield, shoot cerium, and grain sugar/starch remained unaffected, grain protein content significantly increased (24.8% at 100 mg/kg, 32.6% at 400 mg/kg).

Conclusions:

• Nano-ceria exposure affects wheat physiology and cellular structure throughout its lifecycle, with concentration-dependent effects.
• Despite alterations, nCeO2 did not negatively impact overall yield or biomass but enhanced grain protein content.
• Further field studies across plant lifecycles are recommended to fully understand nCeO2 ecotoxicity and agricultural potential.