Abscisic acid

REDIRECT Abscisic acid

"Abscisic acid" redirects here. For the plant hormone, see Abscisic acid.

Overview

Abscisic acid (ABA) is a plant hormone involved in many developmental processes and stress responses. It plays a crucial role in seed dormancy, stomatal closure, and plant stress responses.

Biosynthesis

Abscisic acid is synthesized in the chloroplasts of plant cells. The biosynthesis pathway involves the conversion of carotenoids into ABA through a series of enzymatic reactions. The key intermediate in this process is xanthoxin, which is converted into ABA through oxidation and other modifications.

Function

Abscisic acid is primarily known for its role in:

• Seed Dormancy: ABA helps maintain seed dormancy by inhibiting germination. It ensures that seeds only germinate under favorable conditions.
• Stomatal Closure: In response to drought stress, ABA induces the closure of stomata to reduce water loss through transpiration.
• Stress Response: ABA is involved in the plant's response to various abiotic stresses, such as drought, salinity, and cold.

Signal Transduction

The ABA signal transduction pathway involves several components, including receptors, secondary messengers, and transcription factors. The perception of ABA by its receptors leads to a cascade of events that ultimately result in physiological and developmental changes in the plant.

Related pages

• Plant hormone
• Seed dormancy
• Stomatal closure
• Plant stress responses

Gallery

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  Structure of Abscisic Acid
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  Biosynthesis pathway of Abscisic Acid
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  ABA Signal Transduction Pathway