Comparative growth, biochemical and antioxidative response of Glycine max and Sesamum indicum to MnS nanoparticles

Manganese is an important micronutrient that affects plant growth and development. This study proved that Manganese Sulfide nanoparticles (MnS NPs) are a better alternative to manganese salt (MnSO₄) for the growth of Sesamum indicum and Glycine max under in vivo conditions. SEM, FTIR, EDX and, XRD revealed spherical, pure and, 8 nm size of MnS NPs. The addition of MnS NPs to the soil increased root and shoot length, number of branches, biomass, and protein contents in a dose-dependent manner up to 40 mg/kg in both G. max and S. indicum. Atomic Absorption Spectroscopy (AAS) showed bioaccumulation of Mn at 103.8 and 50.4 mg/kg DW in G. max root and shoot respectively at 80 mg/kg NPs soil and, 127.6 and 84.6 mg/kg DW in S. indicum root and shoot respectively at 80 mg/kg NPs soil. NPs application leads to the activation of antioxidant enzymes (SOD, POD) and the synthesis of secondary metabolites (total phenolics and flavonoids) in a concentration-dependent manner. The extract obtained from NPs treated plants showed higher total antioxidant capacity (TAC), total reducing power (TRP), and DPPH free radical scavenging activity. The hierarchical cluster analysis indicates 40 and 60 mg//kg soil NPs to be the stimulant of plant growth and alkaloid production. The results show that MnS NPs application influenced the plant biochemical profile, and enzymatic and non-enzymatic antioxidants in a dose-dependent manner. Therefore, MnS NPs can be novel elicitors to improve plant growth and biological contents.