Plant Hormones and pathogenic defense Flashcards
1
Q
What are the six hormones of plants?
A
- Auxin (IAA)
- Cytokinins
- Gibberellins
- Brassinosteroids
- Abscisic acid (ABA)
- Ethylene
2
Q
Auxin (IAA) functions
A
- Stimulates stem elongation (low concentration only).
- promotes the formation of lateral and adventitious roots.
- Regulates development of fruit.
- enhances apical dominance.
- Promotes vascular differentiation.
- Retards leaf abscission.
3
Q
Where is the site of Auxin synthesis?
A
Shoot apical meristems and young leaves
4
Q
Cytokinins functions
A
- Regulate cell division in shoots and roots.
- Modify apical dominance and promote lateral bud grown.
- promotes movement of nutrients into sink tissues.
- stimulate seed germination.
- Delay leaf senescence. (Death)
5
Q
Where is cytokinins primarily synthesized?
A
In roots
6
Q
Gibberellins functions
A
- stimulates stem elongation, pollen development, pollen tube growth, fruit growth, and seed development and germination.
- regulates sex determination and the transition from juvenile to adult phases.
7
Q
Where is Gibberellins synthesized?
A
Meristems of apical buds and roots, young leaves, and developing seeds
8
Q
Brassinosteroids functions
A
- promote cell expansion and cell division in shoots.
- Promote root growth at low concentrations.
- Inhibit root growth at high concentrations.
- promote xylem differentiation and inhibit phloem differentiation
- promote seed germination and pollen tube elongation
9
Q
Abscisic acid (ABA) functions
A
- Inhibits growth
- promotes stomatal closure during drought stress
- Promotes sees dormancy and inhibits early germination
- Promotes leaf senescence and desiccation tolerance
10
Q
Where is ABA synthesized?
A
In almost all plant cells (tissue)
11
Q
Ethylene functions
A
- Promotes ripening of many types of fruit, leaf abscisson, and the triple response in seedlings
- Enhances the rate of senescence
- Promotes root and root hair formation
- Promotes flowering in pineapple family
12
Q
Where can ethylene be produced?
A
In almost all parts of a plant.
