Effect of Different Anions On IAA Oxidase and IAA Carboxyproton in OAT Seedlings Under Saline Environment

Under saline environment IAA oxidase activity of oat seedlings increased while the level of native IAA decreased which was in proportion to anions present. In vitor, IAA formed an unstable complex with CO₃ and HCO₃ as a replacement of carboxyproton of IAA, resulting in the formation of sodium salts. In presence of Na₁SO₄ and NaCl carboxyproton of IAA get readily ionised, so that H⁺ ions catalyse oxidation of IAA in presence of IAA destroying enzyme. Thus, plant growth is basically regulated by change in osmotic system and ion specificity is also controlled by hormonal level of IAA through IAA oxidase activity and change in carboxy proton of IAA.