Magnesium oxide nanoparticles improved biochemical and antioxidant parameters of radish to induce salt stress tolerance

Radish is a biochemically enriched root-grown vegetable, consumed around the globe. However, radish productivity is significantly hampered by soil salinity, necessitating sustainable mitigation strategies. Nanomaterials are identified as a potential replacement for chemical fertilizers to target sustainable agricultural productivity. However, each type of nanomaterial needs to be experimentally evaluated for its influence on plant types. Given this, we document the growth-promoting effect of biologically synthesized magnesium oxide nanoparticles (MgO-NPs) via nanopriming on radish growth. MgO-NPs induced a notable increase of 65 % in shoot elongation and 93 % in total chlorophyll level of radish, respectively. Likewise, the carbohydrate level was increased by 24 % on nanopriming. MgO-NPs considerably decreased the protein precipitable tannins by 95 % to the control, thus inducing 94 % increase in the protein accumulation of radish. Furthermore, nanopriming induced 50 % increase in total phenolics, 493 % increase in flavonoids, and a 22 % enhancement in the free radical scavenging potential of radish, thus collectively reducing the oxidative stress by 75 % compared to the control. Further, MgO-NPs-primed radish plants showed significantly enhanced salt stress tolerance than non-treated control plants. Nanopriming was observed to induce an increase of 53 and 10 % in the level of carbohydrates and proteins of salt-stressed radish. Likewise, the antioxidant enzyme activities and non-enzymatic polyphenolics were enhanced by 16–60 and 33–34 % on MgO-NPs priming of salt-stressed radish. Therefore, MgO-NPs enhanced the antioxidant potential and carbohydrates and protein levels contributing to the observed salt stress tolerance in radish. Hence, the present study documents the efficacy of biologically synthesized MgO-NPs applied through seed nano priming in specifically alleviating salt stress via enhancing biochemical resilience in radish.