*2.2.1 Osmotic stress and ionic stress*

High soil salinity is bound to cause osmotic stress, followed by ionic stress. These two high soil salinity-caused direct stresses (ionic and osmotic) induce secondary stresses such as oxidative stress. Increased Na<sup>+</sup> ions in the soil mainly cause osmotic stress. Equilibrium in ion homeostasis is severely disturbed, which includes an increase in the Na<sup>+</sup> levels, K<sup>+</sup> efflux, K<sup>+</sup> leakage, K<sup>+</sup> deficiency in the cytosol, replacement of Ca2+ with Na+, and eventual impaired Na+ /K<sup>+</sup> ratio, nutritional disbalance, and disrupted enzyme activity [11, 12, 15]. Significantly reduced water absorption, decreased osmotic potential, closure of the stomata, inhibited CO2 influx, and impaired downstream processes were reported as a result of osmotic stress in plants [22–24].
