1. Caffeine’s Effect on Mung Bean Germination and growth
Todd Oravitz
9th grade
central catholic

2. INSPIRATION

3. caffeine Naturally occurring substance Bitter, white purine compound
Similar chemical structure to adenine and guanine
Adenine and guanine found in DNA and bind to thymine and cytosine, respectively.

4. Caffeine effects
Blocks adenosine receptors, leading to calcium loss in plant cells
Low calcium can cause problems with
Cell membrane permeability
Cell plate formation

5. Caffeine effects Interferes with plant cytokinesis
Stops Golgi vesicles from fusing with membranes by decreasing ATP activity
Has been shown to inhibit cell division in plants

6. Caffeine in nature Pesticide-like protection to plants containing it
Germination of competing seedlings may be slowed by plants depositing caffeine in nearby soil

7. Guarana plant Effective natural stimulant
Seeds contain about twice the caffeine concentration as those from coffee

8. Guarana plant
Naturally alters one’s perception of fullness, leading to weight loss
FDA recognizes it as “generally safe”

9. Purpose
To determine if caffeine has an effect on germination and growth of mung beans

10. HYPOTHESeS
Null
Caffeine will not have a significant effect on mung bean germination and growth
Alternative
Caffeine will have a significant effect on mung bean germination and growth

11. materials Seed starter trays Potting soil Mung beans
Guarana – caffeine source
Sunlight via window
Room lights
Tap water
Pyrex 500mL measuring cup (to make test solution)
10mL measuring cup (for watering)
Ruler
Scientific scale
(no continuous, dedicated light source)

12. procedure Planted mung beans 72 plants each in test and control groups
5 mL caffeine solution [200mg/L] given every other day to test group
5 mL tap water given every other day to control group
Per research, 3.8cm is optimal depth for planting mung beans.

13. procedure Main shoot height of mung beans measured daily for 28 days
Mung bean mass measured on day 28:
Plant removed, rinsed with tap water and cut at ground level
Above and below ground wet masses measured, then added for total
Procedure repeated after air drying for three hours to obtain dry mass

14. Caffeine
control
DAY 28

15. Germination analysis No growth Growth Total Caffeine 51 21 72 Control19 53 70 74
144
Highly significant difference in the NUMBER of mung beans that grew between caffeine and control groups.
Χ2 = , p <

16. conclusions Null hypothesis rejected
Alternative hypothesis accepted – caffeine had a significant effect on mung bean germination and growth
Specifically, it significantly decreased the number of mung beans that germinated

17. Question
When caffeine group mung beans did germinate, did they exhibit similar growth characteristics to control?

18. CAFFEINE EFFECT ON SHOOT HEIGHT
general
linear
modeling,
p = 0.812
avg shoot height (mm)
blue-caffeine
green-control
General Linear Modeling – way to evaluate how similar the 2 curves are; kind of like comparing the slope of 2 lines. Average growth per plant for plants that grew (eliminated those with no growth).
day

19. Height analysis Daily average mung bean shoot height compared
Only plants that germinated
No significant difference between caffeine and control average daily shoot heights
General Linear Modeling w/p value – the 2 curves are NOT SIGNIFICANTLY DIFFERENT

20. AVG MASS/PLANT – WET mass (g) wet mass above ground below ground total
T-test with significant p value only for below ground wet mass. Average wet mass/plant for plants that had growth (dropped ones that did not grow).
wet mass
above ground
below ground
total
caffeine, g
0.297
0.261
0.558
control, g
0.259
0.308
0.567
p value
0.052
0.035
0.785
significant? no
yes

21. AVG MASS/PLANT – DRY dry mass above ground below ground total
T-test with significant p value only for above ground dry mass. Average dry mass/plant for plants that grew (eliminated ones that did not grow).
dry mass
above ground
below ground
total
caffeine, g
0.224
0.129
0.353
control, g
0.176
0.142
0.318
p value
0.009
0.262
0.125
significant?
yes no

22. ABOVE/BELOW GROUND WET MASS RATIO

23. Mass analysis T-test done for all 6 subgroups
Significant difference seen in 2
Below wet (p=0.035) and above dry (p=0.009)
No significant difference in the other 4
Above wet, total wet, below dry and total dry
Overall, then, no significant difference between caffeine and control mass, when broken down into the subgroups. T-tests done for all 6 subgroups.

24. HEIGHT, WET MASS CORRELATION
blue – caffeine;
R=0.963
green – control;
R=0.807
p<0.001
height (mm)
Only plotted height vs mass for those plants that grew (dropped ones with no growth).
total wet mass (g)

25. HEIGHT, DRY MASS CORRELATION
blue – caffeine;
R=0.941
green – control;
R=0.815
p<0.001
height (mm)
Only plotted height vs mass for those plants that grew (dropped ones with no growth).
total dry mass (g)

26. Height vs mass analysis
Height vs total wet and dry mass
Only plants that germinated
Pearson correlation coefficient
Height correlated with mass in both wet and dry groups
PCC – way to look at how shoot height correlated with mass. NO SIGNIFICANT DIFFERENCES BETWEEN HEIGHT/MASS OR CAFFEINE/CONTROL. More evidence that when mung beans grew in the caffeine group, they grew just like those in the control group.

27. conclusions Null hypothesis rejected
Alternative hypothesis accepted – caffeine had a significant effect on mung bean germination and growth
Specifically, it reduced the number of plants that germinated

28. conclusions
Mung beans in the caffeine group that did germinate, however, showed similar growth to control
No significant differences in
Average daily shoot height
Average total wet mass
Average total dry mass
Kind of a secondary conclusion – when caffeine mung beans grew they were the same as control plants.

29. Limitations and extensions
Did not control soil content
Short drying time
Inconsistent lighting
Extensions
Different caffeine concentrations
Correlate pre-planting mung bean mass with germination
Defined non-sunlight source

30. bibliography ag.arizona.edu/pubs/garden/mg/soils/types.html
Arnaud, M.J The pharmacology of caffeine. Prog. Drug Res. 31:
Bonsignore, C.L, and Hepler, P.K. “Caffeine Inhibition of Cytokinesis: Dynamics of Cell Plate Formation- Deformation in vivo.” Protoplasma. 129, 28-35; 1985.
en.wikipedia.org/wiki/guarana
Etherdon, G.M., and M.S. Kochar Coffee: Facts and controversies. Arch. Fam. Med. 2(3):
extension.oregonstate.edu/lane/sites/default/files/docume nts/cffee07.pdf
Hazardous Substances Data Bank Caffeine. HSDB number 36. Bethesda, MD: National Library of Medicine.

31. Bibliography
Hepler, P.K. “Calcium: A Central Regulator of Plant Growth and Development.” Plant Cell 2005; 17;
Kabagambe, Edmond K. "Benefits and Risks of Caffeine and Caffeinated Beverages." UpToDate. Wolters Kluwer Health, 27 Feb 2013.
Lopez-Saez, J.F. et al. “ATP level and caffeine efficiency on cytokinesis inhibition in plants.” Eur J Cell Biol Jun; 27(2):
Nathanson, J.A. “Caffeine and related methylxanthines: possible naturally occurring pesticides.” Science (4671), 184-7; 1984.

32. Acknowledgements
Thanks to Mr. Krotec for support and guidance throughout the experiment.
Thanks to James Ibinson, MD, PhD, for help with statistical analysis.
Thanks to my parents for helping me with ideas and suggestions, as well as supply of materials.

33. ANOVA TESTING – above/below wet mass
Anova: Single Factor
SUMMARY
Groups
Count
Sum
Average
Variance
Column 1 21
6.233
Column 2
5.489
Column 3 53
13.718
Column 4
16.345
ANOVA
Source of Variation SS df MS F
P-value
F crit
Between Groups 3
Within Groups
144
Total
147

34. ANOVA TESTING – above/below dry mass
Anova: Single Factor
SUMMARY
Groups
Count
Sum
Average
Variance
Column 1 21
4.701
Column 2
2.71
Column 3 53
9.332
Column 4
7.547
ANOVA
Source of Variation SS df MS F
P-value
F crit
Between Groups 3
1.6E-07
Within Groups
144
Total
147

35. ABOVE/BELOW GROUND dry MASS RATIO