Gibberellins

Outline: Gibberellins as Plant Growth Regulators

  • Introduction

    • Definition of gibberellins

    • Over 100 gibberellins reported from various organisms

    • Denoted as GA1, GA2, GA3, etc.

  • Gibberellic Acid (GA3)

    • One of the first discovered gibberellins

    • Most intensively studied form

    • All GAs are acidic

  • Physiological Responses

    • Wide range of physiological responses in plants

    • Ability to increase axis length

    • Used to increase grape stalk length

    • Causes fruits like apples to elongate and improve shape

    • Delays senescence

  • Applications of Gibberellins

    • Increasing grape stalk length

    • Improving fruit shape and size

    • Delaying senescence in fruits and flowers

  • Conclusion

    • Gibberellins play a crucial role as plant growth regulators

    • Versatile in their applications for enhancing plant growth and development

Gibberellins in Agriculture

  • Fruits on Trees

    • Gibberellins (GA3) extend market period

    • Fruits can stay on tree longer

  • Malting Process in Brewing

    • GA3 speeds up malting process

    • Used in brewing industry

  • Sugarcane

    • Carbohydrate stored as sugar in stems

    • Gibberellins increase stem length

    • Yield increase up to 20 tonnes/acre

  • Juvenile Conifers

    • GAs hasten maturity period

    • Early seed production

  • Bolting in Plants

    • Gibberellins promote bolting

    • Internode elongation before flowering

    • Seen in beet, cabbages, rosette plants

Gibberellins are another kind of promotery PGR. There are more than 100 gibberellins reported from widely different organisms such as fungi and higher plants. They are denotedas GA1, GA2, GA3 and so on. However, Gibberellic acid (GA3) was one of the first gibberellins to be discovered and remains the most intensively studied form. All GAs are acidic. They produce a wide range of physiological responses in the plants. Their ability to cause an increase in length of axis is used to increase the length of grapes stalks. Gibberellins ,cause fruits like apple to elongate and improve its shape. They also delay senescence. Thus, the fruits can be left on the tree longer so as to extend the market period. GA3 is used to speed up the malting process in brewing industry. Sugarcane stores carbohydrate as sugar in their stems. Spraying sugarcane crop with gibberellins increases the length of the stem, thus increasing the yield by as much as 20 tonnes per acre.Spraying juvenile conifers with GAs hastens the maturity period, thus leading to early seed production. Gibberellins also promotes bolting(internode elongation just prior to flowering) in beet, cabbages and many plants with rosette habit.