Abscisic Acid

• ABA acts as a general plant growth inhibitor and an inhibitor of plant metabolism
• ABA inhibits seed germination
• ABA stimulates the closure of stomata and increases the tolerance of plants to various kinds of stresses. Therefore, it is also called the stress hormone
• ABA plays an important role in seed development, maturation and dormancy
• By inducing dormancy, ABA helps seeds to withstand desiccation and other factors unfavourable for growth
• ABA acts as an antagonist to GAs