Effect of Low-Dose Nano Titanium Dioxide Intervention on Cd Uptake and Stress Enzymes Activity in Cd-Stressed Cowpea [Vigna unguiculata (L.) Walp] Plants.

Cadmium contamination of agricultural soils is a serious problem due to its toxic effects on health and yield of crop plants. This study investigates the potential of low-dose nano-TiO as soil nanoremediation on Cd toxicity in cowpea plants. To achieve this goal, cowpea seeds were germinated on Cd-spiked soils at 10 mg/kg for 14 days and later augmented with 100 mg nTiO/kg (nTiO-50 nm and bTiO-68 nm, respectively). The results showed that chlorophylls were not altered by nano-TiO intervention. Cadmium partitioning in roots and leaves was reduced by the applied nano-TiO but significantly higher than control. Ascorbate peroxidase and catalase activities in roots and leaves were promoted by nano-TiO intervention compared to control and sole Cd, respectively. However, magnitudes of activity of enzyme activities were higher in nTiO compared to bTiO treatments. The enhanced enzymes activity led to reduced malonaldehyde content in plant tissues. The study concludes that soil application of nano-TiO could be a green alternative to ameliorate soil Cd toxicity in cowpea plants.