Modulatory effects of selenium nanoparticle against drought stress in canola plants

This work aimed to study the impact of exogenously applied selenium nanoparticle (Se NP) on physiological and biochemical attributes of canola to improve the drought tolerance. Drought stress was imposed by poly ethylene glycol at different concentrations (0, 10 and 15% (W/V)) with or without Se NP (2 and 5 mg/L). Se NP increased plant growth in a dose-dependent manner during drought stress. Se NP boosted chlorophyll precursors such as protoporphyrin, magnesium protoporphyrin, thereby inducing chlorophyll biosynthesis. Enzymes of Krebs cycle, namely aconitase and succinate dehydrogenase, up-regulated by Se NP in canola plants subjected to drought stress. Se NP aided to osmotic regulation and osmotic protection by accumulating osmotic regulatory substances (proline, soluble sugar and protein). Treatment with Se NP reinforced antioxidant defense mechanisms by inducing superoxide dismutase, catalase, peroxidase, total phenol and tocopherol, thereby reducing hydrogen peroxide and malondialdehyde as oxidative stress markers. Thus, Se NP facilitated free radicals scavenging in stressed plants. Generally, Se NP acts as activator for drought stress-related resistance responses and causes the improvement of canola tolerance under drought conditions.