Abscisic acid is also called as stress hormone because the synthesis of abscisic acid is stimulated by drought, water logging and other adverse environmental conditions. It is produced in many parts of the plants but more abundantly inside the chloroplast of green cells. Abscisic acid owes its name to its role in the abscission of plant leaves. In preparation for winter, ABA is produced in terminal buds. This slows plant growth and directs leaf primordia to develop scales to protect the dormant buds during the cold season.
They are antagonistic to gibberellins as gibberellins promotes stem elongation while abscisics acid acts as growth inhibitor.
