What effect does abscissic acid have on plant growth?

Abscisic acid (ABA) is a plant hormone known primarily for its role in regulating various aspects of plant growth and development, particularly in response to environmental stress. One of its key functions is to inhibit growth. When plants experience conditions such as drought, abscisic acid levels increase, leading to the closure of stomata to reduce water loss. This hormone slows down growth processes because it signals the plant to conserve resources and energy rather than expend them on growth.

In addition to its role in growth inhibition, abscisic acid also plays a crucial part in seed dormancy, ensuring that seeds do not germinate under unfavorable conditions. By inhibiting growth, it helps the plant to survive during stressful times, effectively maintaining homeostasis. This is why abscisic acid is characterized primarily by its growth-inhibiting properties, making the understanding of its function critical for comprehending how plants adapt to varying environmental conditions.