Plant Signaling Flashcards
What are phytochromes and chlorophylls?
pigments
What is the function of chlorophyll?
use light to harvest energy and run photosynthesis
What is the function of phytochrome?
uses light to signal plant growth mechanisms
What is photomorphogenesis?
non-directional light response
What is phototropism?
directional light response
Where do plants get red light?
sunlight
What is produced when plants are exposed to red light?
Pr
What is produced when plants are exposed to far red light?
pr and it is converted to Pfr
Is Pr active or inactive?
inactive
Is Pfr active or inactive?
active
What are long day plants?
plants that flower when the days are long
What are short day plants?
plants that flower when days are short
How do long day plants flower?
- Pfr is an activator that activates blooming
- for long day plants, there isn’t enough time to convert all of the pfr to pr, so this stimulates blooming
- this indicates an accumulation of Pfr
How do short day plants flower?
- pfr in this case is an INHIBITOR to growth
- during short day/long nights, more of the pfr is converted to pr
- since the inhibitor is not present, short day plants can flower
Why do plants grow towards blue light?
they absorb it
What does auxin do?
helps with phototropism by signaling lengthening of parts away from light to bend plant
What is gravitropism?
growth of plants towards gravity (the ground)
What does positively gravitropic mean?
roots grow with gravity
What does negatively gravitropic mean?
shoots grow against gravity
What do amyloplasts do?
help roots sink towards gravity
What does auxin drive?
apical bud growth and lateral roots
What does cytokinin drive?
apical root growth and axillary buds
What does auxin inhibit?
axillary buds
What does cytokinin inhibit?
lateral roots
