Seed priming with Calcium oxide nanoparticles improves germination, biomass, antioxidant defence and yield traits of canola plants under drought stress

Abstract

• Seed priming with calcium oxide nanoparticles have remediating effects of drought in canola plants. • Seed priming with calcium oxide nanoparticles improves germination parameters of canola plants exposed to drought stress. • Seed priming with calcium oxide nanoparticles improves the growth and antioxidant defence of canola plants under drought. • •Seed priming with calcium oxide nanoparticles improves performance of canola in terms of yield attributes. Recent advances in calcium signalling have proved that calcium plays a key role in mitigating abiotic stresses and strengthening the internal defence of plants. In the present research, calcium was imparted through seed nano-priming with calcium oxide nanoparticles (CaONPs) at concentrations of 25, 50, 75, and 100 ppm compared to control (0 ppm) under PEG-induced drought in the canola plants. During the germination experiment, seedlings were given drought conditions simulated by PEG-6000 treatment maintaining water potential at -0.15 MPa and pH of 5.5 supplemented with Hoagland solution at room temperature. As a control, no PEG-6000 was given. After the germination experiment, a pot experiment was conducted under artificial climate chambers. Seed nano-priming with 75 ppm CaONPs improved germination percentage and seedling fresh weight by 30% and 34% respectively under drought stress. Seed nano-priming with 75 ppm CaONPs increased the number of leaves by 16%, total chlorophyll contents by 28.9%, improved the number of pods per branch, number of seeds per pod, 100 seed weights, and yield by 29.99%, 73.076%, 35.13%, and 35.18% respectively under drought stress. Furthermore, the levels of antioxidant enzymes were improved and levels of stress indicators declined significantly. Present research recommends the use of CaONPs as pre-sowing treatments to the seed to improve the performance of canola plants.