Indole Acetic Acid

White crystalline powder. Melting point 165-166 ° C (168-170 ° C). Soluble in acetone and ether, slightly soluble in chloroform, insoluble in water.

Used as plant growth stimulant and analytical reagent. Can promote cell division, accelerate root formation, increase fruit setting, and prevent fruit drop

Definition:

Indole-3-acetic acid (IAA) is a naturally occurring plant hormone belonging to the auxin family. It plays a critical role in regulating various physiological and developmental processes in plants, including cell elongation, division, and differentiation.

Mechanism of Action:

IAA promotes cell wall loosening by activating proton pumps and enzymes, enabling cell expansion. It also modulates gene expression to regulate growth and development, particularly in response to light, gravity, and environmental stimuli.

Applications:

1. Agriculture:

   • Enhances plant growth and development in crops.

   • Promotes root elongation and branching.

2. Horticulture:

   • Used in tissue culture and plant propagation to stimulate shoot and root formation.

3. Forestry:

   • Encourages rooting in tree cuttings and improves seedling growth.

4. Research:

   • Widely studied as a model auxin to understand plant growth mechanisms.

Functions in Plants:

• Cell Elongation:
  Stimulates the expansion of plant cells, leading to stem and root growth.

• Root Initiation:
  Encourages the formation of lateral and adventitious roots.

• Tropisms:
  Directs plant responses to light (phototropism) and gravity (gravitropism).

• Fruit Development:
  Contributes to fruit set and growth by promoting cell division and enlargement.

• Senescence Regulation:
  Delays leaf and fruit senescence by maintaining hormonal balance.

Formulations and Usage:

1. Formulations:

   • Powdered or liquid solutions for agricultural and research purposes.

2. Application Methods:

   • Seed Treatment:

     • Coat seeds with IAA to enhance germination and seedling vigor.

     
     

   • Foliar Spray:

     • Apply to leaves to promote growth and development.

     
     

   • Root Dipping:

     • Dip cuttings in IAA solution to stimulate rooting.

     
     

3. Concentration:

   • Effective concentrations typically range from 10 to 1,000 ppm, depending on plant species and application method.

Benefits:

• Improved Growth:
  Enhances overall plant vigor by promoting cell division and elongation.

• Efficient Rooting:
  Boosts root formation and development, particularly in cuttings and transplants.

• Enhanced Productivity:
  Contributes to higher yields and better-quality crops.

Safety and Environmental Considerations:

• Toxicity:

  • Low toxicity when used as directed.

  • Avoid inhalation, ingestion, or prolonged skin contact.

• Environmental Impact:

  • Biodegradable and environmentally safe.

Handling and Storage:

• Storage Conditions:

  • Store in a cool, dry place, away from direct sunlight and moisture.

  • Keep the container tightly closed.

• Safety Measures:

  • Use protective gloves and eyewear when handling.

  • Wash thoroughly after use.

Conclusion:

Indole-3-acetic acid (IAA) is an essential auxin that regulates plant growth and development. Its natural occurrence and effectiveness make it a valuable tool in agriculture, horticulture, and research. Proper application of IAA ensures enhanced productivity, improved plant health, and sustainable growth solutions.