Comparative analysis of abscisic acid recovery on two varieties of rice (Oryza sativa L.) under drought condition

The plant stress hormone, abscisic acid (ABA), acts a crucial role in regulating and mitigating drought stress. The present study evaluates the effects of exogenously applied ABA and adaptation strategies respond to concrete challenges of two rice varieties (Aduthurai 45 and 49) under drought stress conditions. The present findings help to predict the degree of drought resistance variety of rice. The nine different treatments were conducted in ninety-day old plants: PS, NS, and different concentrations (10, 15, 25, 50, 75, 100, and 125 μM) of abscisic acid-treated plants and data were collected. Exogenous ABA treatment significantly increased in morphological characteristics compared to control. The 100 μM concentration increased the chlorophyll pigments, RWC, biochemical parameters (reducing sugar, starch, protein, amino acid, and proline), lipid peroxidation, and antioxidant activities (CAT, POD, SOD, and APX) of ADT-49 compared to ADT-45. The present findings depict that two rice (ADT-45 and ADT-49) varieties under drought imposition decrease the growth characteristics. However, the specific concentration at 100 μM of ABA foliar application has positively enhanced the morphology, RWC, chlorophyll pigments, and biochemical contents. A significantly improved ROS plant defense system was noted to increase enzymatic antioxidant activities and yield characters due to the exogenous application of ABA under drought stress. These results show that the simple and relatively reliable variety ADT-49 was drought tolerant than ADT-45, which was either sensitive to drought stress or drought escape by complete their life cycle by early.