PHYSIOLOGICAL AND MOLECULAR ADAPTATION RESPONSE OF SOYBEAN SEEDLINGS UNDER OSMOTIC STRESS

Water is essential for plant growth and development; however, an excessive and lower amount of water negatively affects crop productivity and survival. In natural ecosystems, flash floods may cause the complete submergence of plants in water, which results in the induction of multiple stress tolerance mechanisms. The conditions underwater and the reaction of plants to these conditions are low oxygen, low light, and nutrient deficiency come under the former category of drought stress and are conditions that the plant faces underwater. Production of endogenous hormones and activation of signaling molecules of the glutamate family are the plant responses to the above stress conditions. A high risk of infection is a consequence of being immersed in water. In this study, we aimed to explore soybean's tolerance mechanisms and acclimatization responses to partial and complete submergence and drought at the physiological and molecular levels, which will provide insights into the regulatory networks eliciting tolerance during water stress. The results suggested that upon exposure to the osmotic stress, there is an increase in the concentration of histidine, arginine, proline, and glutamate contents in the complete submergence and drought stress group as compared to the control group. Moreover, the results also suggested that the SA level increases in its 12 hours and then decreases in the next 120 hours. Interestingly the regulation of ABA is the opposite. It increases as it increases with time. An increased width leaf was observed in all study groups except the control group.