Hormones Flashcards
They regulate plant functions
Plant hormones
Are chemical messengers produced in one part of an organism that stimulates or suppresses activity in another part
Hormones
(What Plant Hormones…)
1. It induces growth of shoot
2. It promotes root initiation
3. It stimulates cell elongation
4. It triggers blossoming
- Cytokinin
- Auxin
- Gibberellin
- Florigen
The production of hormones occurs very often at sites of active growth within the ____
meristems
Hormonal Control:
1. Plant Growth Regulators (3)
2. Plant Growth Inhibitors
- Plant Growth Regulators
- Auxin, Gibberellin, Cytokinin - Plant Growth Inhibitors
- Abscisic acid and Ethylene
Are plant hormones that produce dramatic increases in size.
- Ending seed dormancy
- Stimulates stem elongation, germination and flowering
Gibberellin
Causes the ripening of fruits
Ethylene
- Stimulates cytokinesis
- Final stage in cell division
- Produced in growing roots, seeds and fruits
- Involved in growth of side branches
Cytokinins
Cytokinins Key concept in cell division
Cytokinins = More mitosis
More mitosis = More cells
More cells = Plant growth
- Lengthen plant cells in the growing tip
- Stimulates growth of primary stem
- Controls some forms of tropism
Auxins
Is the movement of plant in response to an environmental stimulus
Tropism
Is a plant hormone and is involved in plant defense mechanisms
Jasmonic acid
A defense-boosting hormone as its level increases with pest attack
Salicylic acid
Regulates specific gene sets to help plants sustain during unfavorable environmental conditions
Brassinosteroids
It is essential for proper growth and development of plants
Spatio-temporal action of hormones
