ABSTRACT
Plants tolerate drought, salinity, and heat stresses with the storage of osmotic regulators. Osmotic regulators contain amino acids, sugars, and some mineral ions, hormones, and proteins. Proline is one of the active amino acids in the osmotic regulation phenomenon that plays a significant role in the formation and maintenance of osmotic pressure inside the plant. Osmotic stress is one of the environmental factors limiting plant photosynthesis. Increasing the soluble sugar content is one of the reasons for increasing the internal osmotic pressure of the plant, which attempts to neutralize the osmotic pressure of the environment and even absorb the water in the soil as much as possible. The concept of osmotic pressure regulation is the reduction of osmotic potential in response to water stress. Hence, the breeders are working with various breeding methods to achieve varieties that tolerate drought stress.
