Abscisic Acid

When our bodies require water, we become thirsty. The "thirst signal" shows that we require water. When a plant requires water, such as during a drought, it does not have many alternatives. A rain dance is essentially out of the question.

Plants create abscisic acid, a chemical messenger, to inform the rest of the plant that it is water-stressed. Abscisic acid is produced in droughted leaves, roots, and developing seeds and can move up and down a plant stem in the xylem or phloem, sounding the alarm.

Some of the functions of the Abscisic Acid Hormones are as follows:

• Causes leaf and fruit abscission.
• It inhibits seed germination.
• Induces leaf senescence.
• Accelerates dormancy in seeds, which is important for storage.
• Stimulates stomatal closure to prevent transpiration during water stress.  

That's a quick rundown of the five key plant hormones: auxin, gibberellin, cytokinin, ethylene, and abscisic acid. Remember that hormones are powerful small chemical messengers, yet they would lose their potency if they lingered and accumulated in plant tissues. As a result, they degrade and are replaced over time