What is the role of abscisic acid in plants?

Abscisic acid (ABA) in plants primarily regulates seed dormancy and helps the plant respond to stress conditions.

Abscisic acid is a plant hormone that plays a crucial role in various plant growth and development processes. One of its main functions is to induce seed dormancy. This means it helps to keep the seed in a resting state, preventing it from germinating under unfavourable conditions. When conditions become favourable for growth, such as the right temperature and moisture levels, the concentration of ABA decreases, allowing the seed to break dormancy and germinate.

Another significant role of ABA is in the plant's response to stress, particularly drought stress. When a plant is under water stress, ABA levels increase, causing the stomata (small openings on the leaf surface) to close. This reduces water loss from the plant through transpiration, helping it to conserve water. This is particularly important for plants in arid or drought-prone environments.

ABA also plays a role in the synthesis of storage proteins during the maturation of seeds, helping to ensure the seed has the necessary nutrients for germination and early growth. Additionally, it is involved in the regulation of plant growth and development processes such as cell division and elongation, and the transition from vegetative growth to flowering.

In summary, abscisic acid is a vital plant hormone that helps plants adapt to environmental stresses and regulates key growth and development processes. Its role in managing water stress and seed dormancy makes it particularly important for plant survival and reproduction.