CAFFEINE S EFFECT ON MUNG BEAN GERMINATION AND GROWTH TODD ORAVITZ 9 TH GRADE CENTRAL CATHOLIC

Transcription

1 CAFFEINE S EFFECT ON MUNG BEAN GERMINATION AND GROWTH TODD ORAVITZ 9 TH GRADE CENTRAL CATHOLIC

2 INSPIRATION

3 CAFFEINE Naturally occurring substance Bitter, white purine compound Similar chemical structure to adenine and guanine

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

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 Control Total Χ 2 = , 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 avg shoot height (mm) general linear modeling, p = bluecaffeine greencontrol 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

20 mass (g) AVG MASS/PLANT WET caffeine control wet mass above above ground ground below ground total caffeine, g control, g p value significant? no yes no

21 mass (g) AVG MASS/PLANT DRY caffeine control dry mass above above ground ground below ground ground total caffeine, g control, g p value significant? yes no no

22 ABOVE/BELOW GROUND WET MASS RATIO Caffeine 0.297/0.261 = Control 0.259/0.308 = 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

24 HEIGHT, WET MASS CORRELATION height (mm) blue caffeine; R=0.963 green control; R=0.807 p<0.001 total wet mass (g)

25 height (mm) HEIGHT, DRY MASS CORRELATION blue caffeine; R=0.941 green control; R=0.815 p<0.001 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

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

29 LIMITATIONS AND EXTENSIONS Limitations 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; 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 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. 226 (4671), 184-7;

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 Column Column Column ANOVA Source of Variation SS df MS F P-value F crit Between Groups Within Groups Total

34 ANOVA TESTING ABOVE/BELOW DRY MASS Anova: Single Factor SUMMARY Groups Count Sum Average Variance Column Column Column Column ANOVA Source of Variation SS df MS F P-value F crit Between Groups E Within Groups Total

35 ABOVE/BELOW GROUND DRY MASS RATIO mass ratio Caffeine 0.224/0.129 = Control 0.176/0.142 = 1.239