Plant Hormones Flashcards
What are plant hormones?
Chemical signals that modify or control one or more physiological processess
Are plant hormones produced in low or high concentrations?
Low, but they have have big effects on growth and development
Are plant hormones mobile?
Yes!
What are the major plant hormones?
Auxin
Cytokinins
Gibberellins
Abscisic acid
Ethylene
Which plant hormones are involved in growth?
Auxin: to grow/increase
Cytokinins: cell division
Gibberellins: to expand
Which plant hormones are involved in stress control?
Abscisic acid
Ethylene
Which hormone promotes vertical/apical growth?
Auxins
What plays a role in pattern formation of plants, especially roots?
Polar transport of auxins
Where is the primary site of auxin synthesis?
SAM and young leaves
What are auxins used for?
Root growth and plant killer (if overdosed)
If a plant suddenly became bushier, what might the cause be?
The removal of a terminal bud
What do cytokinins work with auxin to control?
Cell division and differenciation
Where are cytokinins produced?
Actively growing areas like roots, embryos, and fruits
What do gibberellins do?
Cell elongation
A release of _______ from the embryo signals seeds to germinate
Gibberellins
What does Abscisic acid (ABA) do/what two effects?
Slows growth
- Seed dormancy
- Drought tolerance
Early germination is caused by?
Inactive/low levels of ABA
How does ABA cause drought tolerance?
Accumulation causes stomata to close rapidly
If a banana were ripening, which hormone is affecting the fruit?
Ethylene
What is senescence?
The programmed death of cells/organs
A burst of _____ is associated with apoptosis (programmed cell death)
Ethylene
What controls leaf abscission (the falling of leaves)
Auxins and ethylene
