Question

How does gibberellin actually work?

Answer 1

Gibberellin:

1. Gibberellin are terpene derivatives in the form of weak acids.
2. For the first time, a Japanese paid attention to 'bakanae', also known as the ‘foolish seedling disease’ of rice.
3. The cause of this disease was a fungus called Gibberella fujikoroi.
4. Due to the disease some seedlings of rice grew excessively tall.
5. In 1930, Yabuta and Hayashi isolated this substance that induced growth and called it gibberellin.
6. The synthesis of gibberellin takes place in the embryo, buds, apices of young leaves, and roots.
7. The precursor of gibberellin is acetyl CoA.

Functions of gibberellin:

1. Bolting: Gibberellin promotes elongation of the stem making it 5-6 times taller than the original plant, as seen in cabbage and beetroot.
2. It promotes the growth of male flowers.
3. It helps in overcoming seed dormancy.
4. In some fruit like apples, pears, etc. gibberellin causes parthenocarpy.
5. It delays fruit ripening in Citrus.
6. It promotes malt yield from barley.