1. Plant Responses to the Environment
Introduction
My goal for this class is to convince you that plants are not as boring as many people think they are.
They are quite dynamic creatures doing amazing things, if observed carefully.
Plants live on a different time scale from that of humans and other animals. Often we have to use time lapse video images to catch their movements.

2. Plants respond to many environmental stimuli

3. Plants respond to the direction of light
CB 39.0

4. Spectrum of light energy
CB 10.6

5. Photosynthesis:
Plants can make sugar using energy from the sun, water from the ground, and CO2 from the air.
CB 10.5

6. Action spectrum of photosynthesis
CB 10.9

7. Seedling germination may depend on light
CB 39.18

8. Light quantity and quality in different environments

9. Seedling germination may depend on light
CB 39.18

10. Phytochrome: a reversible receptor
CB 39.20

11. Shade Avoidance
direct light
shade

12. Light quality is different in shade…more far-red
direct light
shade

13. Why is phytochrome reversible?

14. Light quality is different in shade…more far-red
direct light
shade

15. Plants respond to many environmental stimuli

16. Plants respond to touch
CB 39.26

17. Plants respond to touch
touched
not touched
CB 39.26

18. Another touch response
CB 39.27

19. Bad touch: Herbivory

20. Bad touch: Herbivory
sytemin

21. Bad touch: Herbivory
Jasmonic acid
systemin

22. Bad touch: Herbivory Jasmonic acid systemin Protease Inhibitors

23. Bad touch: Herbivory Jasmonic acid systemin I’ve got indigestion!
Protease
Inhibitors
Protease
Inhibitors
Protease
Inhibitors
Jasmonic acid
Protease
Inhibitors
systemin
Protease
Inhibitors
Protease
Inhibitors
I’ve got indigestion!

24. Insect saliva can let plants know which insect is attacking
plants respond to both the wound (mechanical damage) and to insect derived compounds, but they can tell the difference between a mechanical wound and an insect caused wound.
- plants can sense insect saliva proteins that trigger a defense response

25. Plants release several volatile chemicals to signal other organisms
CB 39.29

26. Plants release several volatile chemicals to signal other organisms
Plant biology: Night moves of pregnant moths
Clarence A. Ryan (29 March 2001) Nature 410,

27. Moth type and time
Plants release different volatiles depending on who and when they are being eaten.
De Moraes C. M., Mescher M. C., Tumlinson J. H. Nature 410, (2001)

28. Plants release several volatile chemicals to signal other organisms
Plant biology: Night moves of pregnant moths
Clarence A. Ryan (29 March 2001) Nature 410,

29. Marine Biology…