Impact of magnetite iron oxide nanoparticles on wheat ( Triticum aestivum L.) development: Evaluation of oxidative damage

Abstract

Interest on the environmental impact of engineered nanomaterials has rapidly increased over the pastyears because it is expected that these materials will eventually be released into the environment. In thiswork, physiological effects and possible cell internalization of citric acid coated-Fe3O4 nanoparticles(5, 10, 15, 20 mg L1) on wheat (Triticum aestivum L.) plants grown five days under hydroponic conditionswere evaluated. Visualization of root sections by transmission electron microscopy showed that Fe3O4nanoparticles entered the root through the apoplastic route and were then detected in the root epidermalcell walls. Moreover, strong magnetic signals detected by vibrating sample magnetometry (VSM) and ahuge increment in the Fe content (8,07 and 2,01 mg g1 DW for NP20 and C-NP20 treatmentsrespectively) were observed in wheat roots treated with Fe3O4 nanoparticles. However, no superparamagneticsignal was detected in the aerial part which indicated that magnetite nanoparticles werenot translocated by vascular tissues in wheat plants in the experimental conditions of this study.Moreover, Fe3O4 nanoparticles did not affect the germination rate, the chlorophyll content, and theplant growth, and they did not produce lipid peroxidation, nor alter O2 or H2O2 accumulation respect tocontrol plants. Furthermore, electrolyte release and cell death percentage were not modified bynanoparticle treatment. The antioxidant enzyme activities of NP treated plants significantly increased inboth the root and the aerial part respect to the controls, showing a response leading to prevent oxidativedamage. These preliminary results show that these Fe3O4 nanoparticles are not phytotoxic, suggestingthat they could potentially be useful for the design of new products for agricultural use.