Effect of nanoceria (CeO2) and sodium nitroprusside (SNP) on germination and seedling growth of Pishgam wheat variety under drought stress

A factorial experiment with three replications was conducted based on CRD to evaluate the influence of nanoceria and sodium nitroprusside in improving germination and biochemical characteristics of wheat under drought stress. The effects of nanoceria including 0, 500, 1000 and 2000 mg L-1 as well as 0 and 100 μM sodium nitroprusside as NO donor were studied under levels of drought stress (0, -0.4 and -0.8 MPa). Drought stress increased MGT, the activity of SOD, CAT, APX enzymes and MDA content in wheat seedlings but reduced other studied parameters such as germination percentage and germination rate. Simultaneous application of nanoceria and sodium nitroprusside significantly affected some studied parameters. Application of nanoceria (1000 mg L-1) + sodium nitroprusside enhanced germination percentage and seed vigor index by 44.5 and 75.5 percent respectively under -0.8 MPa drought stress. Aforementioned treatment also improved the activity of SOD and APX by 19.7 and 41.1 percentage respectively and decreased MDA content in wheat seedling by 33.5 percentage under -0.8 MPa drought stress. It seems that sodium nitroprusside and nanoceria alleviate the adverse effects of drought stress on wheat seedling via improving germination indices and promoting antioxidant defense system.