The Effect of Beta Carotene on Plants Infected with Agrobacterium Tumefaciens Christina Adams Grade 9 Problem • Will Beta Carotene have any role in preventing the effect of Agrobacterium tumefaciens on violets? • I picked this experiment because of my interest in Botany and how different bacteria and solutions can affect the plant’s growth. Research • Beta Carotene is a red-orange pigment found in various types of plants. Beta Carotene is converted in the body to Vitamin A. • Agrobacterium tumefaciens is the bacteria that causes tumor formation in over 140 different dicot plants (plants with 2 or more embyrotic leaves.) • A. tumefaciens can live freely in soil or inside plants as a parasite; Causes disease by transferring its own DNA into plants cells. • Most A. tumefaciens infections caused by wounds in the plants (result from grafting together different plant stocks.) Hypothesis • If Beta Carotene is used, then it should have no effect on preventing damage from the Agrobacterium tumefaciens. Beta Carotene Materials • • • • • • 24 violets Beta Carotene solution Disinfectant Bunsen Burner Inoculating Needle Agrobacterium Tumefaciens Procedure • 8 plants were placed in each pot • Pot A is inoculated with A. tumefaciens and watered with 100ml of beta carotene twice weekly. • Pot B is inoculated with A. tumefaciens and watered with 100ml of distilled water twice weekly. • Pot C is not inoculated, but watered with 100ml of distilled water twice weekly. • The height of the plants will be documented over a 30-day period. Independent and Dependent Variables • Independent variable: what the seeds are germinated in • Dependent variable: the height and growth rate of the plants • Control: Group C (water control group) Data Control vs. Beta Carotene 25.000% y = 0.0459x + 0.0077 20.000% y = 0.029x - 0.0034 Percent Change 15.000% Control Beta Carotene 10.000% Linear (Control) Linear (Beta Carotene) 5.000% 0.000% -2 -5.000% -1 0 1 2 Time (Weeks) 3 4 5 6 Data Control vs. Bacteria 25.000% y = 0.0459x + 0.0077 Percent Change 20.000% 15.000% y = 0.0096x + 0.0176 Control A. tumefaciens Linear (Control) 10.000% Linear (A. tumefaciens) 5.000% 0.000% -2 -1 0 1 2 Time (Weeks) 3 4 5 6 Data Beta Carotene vs. Bacteria 16.000% 14.000% y = 0.029x - 0.0034 12.000% y = 0.0096x + 0.0176 Percent Change 10.000% Beta Carotene 8.000% A. tumefaciens 6.000% Linear (Beta Carotene) Linear (A. tumefaciens) 4.000% 2.000% 0.000% -2 -2.000% -1 0 1 2 Time (Weeks) 3 4 5 6 Conclusion • If Beta Carotene is used then it will have no effect on A. tumefaciens infections. • This was not supported. • The control group had the highest growth rate followed by the beta carotene group. • The bacterial group had the lowest growth rate -Growth stopped after two weeks and plants began to brown Conclusion (cont) • How to improve experiment: - use different types of plants, such as monocot plants, and different types of solution to test the effectiveness of prevention. - Test the effectiveness of the Beta Carotene on infected plants in higher doses. - Test Beta Carotene on humans with cancer. Works Cited • Bochinski, Julianne Blair. The Complete Handbook of Science Fair Projects. N.p.: n.p., n.d. Print. • Helling, Christopher H. “How Effective is Beta Carotene in Fighting Cancer in Plants?” California State Science Fair 2008 Project Summary. N.p., n.d. Web. 5 Oct. 2011. • Tzfira, Tzvi, and Vitaly Citovsky. “Taking Biology Lessons from a Bug.” The Agrobacterium- Plant Cell Interaction. N.p., n.d. Web. 6 Oct. 2011. • University of Minnesota- Department of Pediatrics. “Agrobacterium Infections in Humans.” University of Minnesota. N.p., n.d. Web. 6 Oct. 2011. • Various school students. “Do Plants Get Cancer?” Student Sheet. N.p., n.d. Web. 6 Oct. 2011. • Thank you for listening!