Efficacy of two different forms of selenium towards reduction of arsenic toxicity and accumulation in Cicer arietinum L.

Arsenic migration from soil to crop plants and subsequently human consumption of contaminated foodstuffs is a serious threat for society. In the present study, two oxidation states of selenium [Se(0) and Se(VI)] were used to check their efficacy towards amelioration of arsenic toxicity in chickpeas (Cicer arietinum L.). Three different concentrations (1, 5, and 10 mg/L) of both oxidation states of selenium were applied separately and in combination against a fixed dose (10 mg/L) of arsenic [(As(V)] treatment on chickpea seedlings. Further, seed germination and seedling growth attributes, oxidative stress, and antioxidant defense under different treatments were analyzed. The changes in anatomical structures and arsenic accumulation in different parts of seedlings were also studied. Results revealed that increased generation of oxidative stress affected physiobiochemical parameters of seedlings and diminished plant growth and deformation in vascular bundles under arsenic stress. However, the combined application of Se with As showed overall improvement in seedling growth, reduced oxidative stress, and organized vascular bundles of chickpea seedlings as compared to arsenic stress alone. The arsenic uptake and accumulation in chickpea seedlings were also reduced upon supplementation of Se. The highest reduction of arsenic accumulation by 42 and 56 % in roots, while 47 and 58 % in shoots were recorded by the application of 10 mg/L of Se(0) and Se (VI) under As stress, respectively. Overall, Se(VI) showed much better performance towards the minimization of arsenic-induced phytotoxicity and arsenic accumulation as compared to Se(0). Therefore, this study explored the efficacy of different forms of selenium towards the mitigation of arsenic toxicity in plants.