Analysis on the Growth Effect of Nano Titanium Dioxide on Lactuca sativa

Abstract:

In order to clarify the effect of nano titanium dioxide particles (TiO₂ NPs) on growth of Lactuca sativa, the growth, physiological and biochemical indexes of L. sativa were studied treated with TiO₂ NPs (300-1 200 mg/L) by using a self-designed hydroponic device. The results showed that the root length, stem length, leaf surface area, fresh weight and dry weight of seedlings increased treated with 300 mg/L TiO₂ NPs. With the increasing of TiO₂ NPs concentration, the growth indexes showed a downward trend, but still higher than those of the control group. The activities of antioxidant enzymes (SOD, POD) in L. sativa decreased significantly at low TiO₂ NPs concen-tration (300 mg/L). With the increament of TiO₂ NPs concentration, the activities of SOD, POD gradually increased. Therefore, it was suggested that L. sativa has a concentration-dependent effect on TiO₂ stress, showing "promotion at low concentration and inhibition at high concentration". The damage of nanomaterials of L. sativa could be reduced by its antioxidant enzyme system.

Key words:Nano titanium dioxide;Lactuca sativa;Concentration dependence;Toxic effect