PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Titanium dioxide nanoparticles (TiO₂ NP) are used worldwide for various applications such as antibacterial agents, photo-catalyst, drug delivery system, sunscreens and electronics. In the present investigation, the effect of TiO₂ NP in promoting the growth of the Brassica juncea L. under cadmium (Cd) and arsenic (As) stress was analyzed. The 28-day-old mustard seedlings were subjected to two sets of treatments. In the first set, seedlings were exposed separately to 6 mM Cd(II), 500 µM As(III) and TiO₂ NP (500 mgl^-1 TiO₂) for 96 h. In the second set, seedlings were exposed, in combination of Cd (II)+TiO₂ NP (6 mM+500 mgl^-1), and As(III)+TiO₂ NP (500 µM+500 mgl^-1) for 96 h. After that chlorophyll content, malondialdehyde content and antioxidant enzymes activity were analyzed. Seedlings under heavy metal (HM) stress showed stunted growth, increased malondialdehyde (MDA) content and antioxidant enzyme activity. The application of TiO₂ NP along with Cd and As ameliorated the deleterious impact of heavy metals by promoting growth of mustard seedlings as compared to individual Cd- and As-alone treatment. Overall, this study concluded that TiO₂ NP supplemented with heavy metal might be a promising approach in mitigating the adverse effects of heavy metal stress on mustard growth and development.