Sustainable agriculture through nano-priming: Evaluating the role of biogenic manganese oxide nanoparticles in mitigating wastewater-induced stress in wheat (Triticum aestivum)

Nanoparticles have potential to mitigate the harmful effects of wastewater in agricultural crop, reducing crop contamination and improving wheat growth and development. However, no information has been reported concerning the impact of seed priming of biogenic MnO-NPs on the germination and physiochemical parameters of wheat crop under wastewater stress condition. The current study examined the impact of primed seed with biosynthesized manganese oxide nanoparticles (MnO-NPs) from Bacillus flexus on wheat growth under wastewater stress. This study was conducted in a pot experiment. Wheat seeds were primed with different concentrations of MnO-NPs (0, 20,40, 60, 80, and 100 mg L-1). Primed seeds were sown in wastewater-polluted soil. The pot experiment was conducted for 30 days. The soil in the pots was kept consistently moist, with moisture levels at about 60-70% of the soil's maximum water-holding capacity. Control included seeds without MnO-NP priming. The wastewater contained contaminants such as heavy metals and organic pollutants. The result showed that 80 mg L-1MnO-NP treatment showed a more positive impact in combating wastewater stress. MnO-NPs at 80 mg L-1 positively influenced wheat seed germination parameters up to 57% and growth attributes by 63.75% compared to the control treatment. Moreover, seed priming with MnO-NPs at 80 mg L-1 improved gas exchange attributes by 67%, increased chlorophyll contents by 53.5%, and enhanced antioxidant enzyme activities: 38% for superoxide dismutase (SOD), 61% for ascorbate peroxidase (APX), 65% for catalase (CAT), and 55% for peroxidase (POD). Meanwhile, hydrogen peroxide(H2O2), malondialdehyde (MDA), and electrolyte leakage (EL) were decreased by 51%, 69%, and 52% respectively. These results demonstrate that primed seed with MnO-NPs can significantly enhance wheat's germination and biochemical attributes under wastewater stress, providing a promising approach for improving crop resilience and productivity in wastewater polluted conditions.