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!