Crosstalk between Abscisic Acid and Auxin under Osmotic Stress

Since their early migration from aquatic environments to land, plants have been susceptible to numerous variable environmental stresses, which strongly influenced their growth and development. Among these, osmotic stress is potentially one of the most catastrophic stresses. Phytohormones immensely contribute to the adaptation of plants in response to these stresses, and much research has been done regarding crosstalk between different plant hormones in synergistic or antagonistic interactions. However, the possible associations between auxin and abscisic acid (ABA) under changing environmental conditions (especially osmotic stress) have not been well clarified at this time. Biologists are becoming increasingly interested in revealing the possible crosstalk between ABA and auxin in the acquisition of these stress resistance mechanisms. Recently, progress has been made in identifying the stress perception, transduction, and possible biosynthetic signaling pathways of the two endogenous hormones and the genes that are key mediators of their pathways. However, there is still a large information gap regarding the ABA-auxin crosstalk module under osmotic stress. Given the current state of information, we focused on summarizing the converging points of ABA and auxin under osmotic stress, as this could potentially be a strong topic of extensive research in the coming years.