PLANT HORMONES
PLANT HORMONES
• All are produced in specific parts of the plant – eg shoot tip
PLANT HORMONES
• All are produced in specific parts of the plant – eg shoot tip
• Transported to other parts of the plant – eg region of elongation
PLANT HORMONES
• All are produced in specific parts of the plant – eg shoot tip
• Transported to other parts of the plant – eg region of elongation
• Effective in very small amounts.
TYPES OF HORMONES
• Auxins
- Produced in tips of roots and short and promote elongation and differentiation
of the cells.
TYPES OF HORMONES
• Auxins
- Produced in tips of roots and short and promote elongation and
differentiation of the cells.
- Responsible for apical dominance in which the main stem is the dominant
growth site as growth of side stems is suppressed.
TYPES OF HORMONES
• Auxins
- Produced in tips of roots and short and promote elongation and
differentiation of the cells.
- Responsible for apical dominance in which the main stem is the dominant
growth site as growth of side stems is suppressed.
- Main Auxin is Indole Acetic Acid (IAA)
TYPES OF HORMONES
• Gibberellins
- Similar production sites and effects as Auxins.
TYPES OF HORMONES
• Gibberellins
- Similar production sites and effects as Auxins.
- Promotes growth by rapid elongation of cells, especially those of the stem
between the nodes (where side branches and leaves come off).
TYPES OF HORMONES
• Gibberellins
- Similar production sites and effects as Auxins.
- Promotes growth by rapid elongation of cells, especially those of the stem
between the nodes (where side branches and leaves come off).
- Also known as ‘bolting hormone’
TYPES OF HORMONES
• Gibberellins
- Similar production sites and effects as Auxins.
- Promotes growth by rapid elongation of cells, especially those of the stem
between the nodes (where side branches and leaves come off).
- Also known as ‘bolting hormone’
- Promotes cell differentiation of cambium.
TYPES OF HORMONES
•
-
Gibberellins
Similar production sites and effects as Auxins.
Promotes growth by rapid elongation of cells, especially those of the stem between
the nodes (where side branches and leaves come off).
- Also known as ‘bolting hormone’
- Promotes cell differentiation of cambium.
- Breaks dormancy of seeds and buds.
TYPES OF HORMONES
• Cytokinins
- Produced in the tips of roots and promotes cell division/mitosis.
TYPES OF HORMONES
• Cytokinins
- Produced in the tips of roots and promotes cell division/mitosis.
- Balance the growth in roots ad short, and also act to slow aging of tissues.
TYPES OF HORMONES
• Abscisic Acid
- Promotes formation of abscission zone, the layer of cells where leaves and
fruit fall from the tree.
TYPES OF HORMONES
• Abscisic Acid
- Promotes formation of abscission zone, the layer of cells where leaves and
fruit fall from the tree.
- Promotes seed dormancy
TYPES OF HORMONES
• Abscisic Acid
- Promotes formation of abscission zone, the layer of cells where leaves and
fruit fall from the tree.
- Promotes seed dormancy
- Stimulates closing of stomata in most plants.
TYPES OF HORMONES
• Ethene
- Produced and accumulates in aging fruit, promoting their ripening.
TYPES OF HORMONES
• Ethene
- Produced and accumulates in aging fruit, promoting their ripening.
- Produced in aging leaves, assisting in their fall.