Response of Exogenous Abscisic Acid on Antioxidant Enzymes in Rice under Salinity Shock

Effect of abscisic acid (ABA 0.1 mM) as foliar spray was studied on salinity induced antioxidant enzymes and proline content in three contrasting rice cultivars. Salinity shock was imposed on rice cultivars for 72 hours at flowering stage. ABA spray improved RWC (81.7%) as compared to control (75.4%). Proline content and antioxidant enzymes activity significantly increased with increasing salinity level. Maximum proline content was observed in Dandi at 300 mM NaCl. A non-significant effect of foliar ABA spray was observed on proline content and catalase activity but the activities of superoxide dismutase, ascorbate peroxidase and guiacol peroxidase significantly increased. The salt tolerant variety Dandi is more responsive to ABA for up-regulation of antioxidant enzymes activity under salinity shock.