Synthesis of Gibberellin in Plants
Gibberellins are plant hormones that play a crucial role in various aspects of plant growth and development. They are synthesized in specific tissues of the plant, primarily in the meristematic regions such as the shoot and root tips.

Key Points
- Biosynthesis Pathway: The biosynthesis of gibberellins starts with the conversion of geranylgeranyl diphosphate (GGDP) to ent-kaurene through a series of enzymatic reactions. This pathway involves several enzymes such as copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS).
- Conversion to Active Gibberellins: Ent-kaurene undergoes further modifications to form active gibberellins, such as GA1, GA3, and GA4. These active forms play a crucial role in regulating various physiological processes in plants, including seed germination, stem elongation, and flowering.
- Tissue-Specific Synthesis: The synthesis of gibberellins is tissue-specific, with different tissues expressing specific enzymes involved in the biosynthetic pathway. For example, the shoot apex is a significant site for gibberellin synthesis, as it is essential for stem elongation and leaf expansion.
- Regulation: The synthesis of gibberellins is tightly regulated by various internal and external factors, such as light, temperature, and hormonal interactions. For instance, gibberellin biosynthesis is upregulated in response to environmental cues to promote plant growth and development.
In conclusion, the synthesis of gibberellins in plants occurs in specific tissues through a series of enzymatic reactions. These plant hormones play a crucial role in regulating various physiological processes and are essential for plant growth and development.