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2014
Measuring Photosynthesis to Evaluate
Photoprotection by Anthocyanins in Malosma
laurina
Jorge Bojorkez-Calderon
Pepperdine University
Hannah Imson
Pepperdine University
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Bojorkez-Calderon, Jorge and Imson, Hannah, "Measuring Photosynthesis to Evaluate Photoprotection by Anthocyanins in Malosma
laurina" (2014). Pepperdine University, All Undergraduate Student Research. Paper 113.
http://digitalcommons.pepperdine.edu/sturesearch/113
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Measuring Photosynthesis to Evaluate Photoprotection by Anthocyanins in Malosma laurina Jorge Bojorkez-Calderon & Hannah Imson
Pepperdine University, Seaver College
Abstract
Anthocyanin, like chlorophyll, is a pigment
molecule present in plants. However, while
chlorophyll reflects green light, anthocyanin
reflects red light, a much lower frequency,
and therefore absorbs less energy. Pigment
molecules are very involved in
photosynthesis in that they absorb the
energy needed to push those reactions
forward, and carotenoids and anthocyanins
function to take absorb excess sunlight
(Bliger and Björkman 1990). Anthocyanins
in particular, have also been speculated to
protect again UV damage (Merzlyak and
Chivkunova 2000).
Malosma laurina, also known as laurel
sumac, utilizes this pigment molecule to
help defend against the Mediterranean-like
environmental conditions it faces. The
juvenile leaves of Malosma are easily
identified by their rich red color and soft
leaves, while the mature leaves are tougher
and green colored.
Through the use of Li-6400 XT, the objective
of our group is to determine the difference in
photo-protection levels between the red,
juvenile leaves and the green, juvenile
leaves of Malosma laurina. We will be
observing the differences in photosynthetic
rates, as well as the various fluorescence
values. We expect to see lower
photosynthetic rates in the red leaves.
•  CO2 = 400 µmol/mol
•  Li-6400XT Portable Photosynthesis
System
•  Temperature = 23ºC
In order to determine whether or not anthocyanins play an essential role in the photoprotection
of Malosma laurina, photosynthesis was measured using the Li-6400XT Portable Photosynthesis
System. Constant variables were used to determine any changes in the leaf’s ability to enable
the process of photosynthesis. The only variable that was increased throughout the experiment
was the amount of photons (Quantum), which was increased in increments of 200 µmol m-2 s-1
from 1000 to 2000 µmol m-2 s-1. All data was collected on Pepperdine’s campus.
Results
There were several significant differences
identified between the red and green
leaves of Malosma laurina. While the
photosynthetic rates of the green leaves
averaged 20, the photosynthetic rate of the
much younger red leaves averaged 4.
This significant difference is due to the
presence of anthocyanin, which absorbs
excess light and various energies of light
at lower frequencies than chlorophyll can
absorb. Therefore, our group can
conclude that the presence of anthocyanin
is very effective in the photoprotection of
the juvenile leaves.
22
4
References
2
Photosynthesis (µmol/m s)
Introduction
•  Juvenile red and green leaf
Photosynthesis (µmol/m s)
Conclusion
•  Flow = 300 µmol m-2 s-1
•  Laurel Sumac (Malosma laurina)
2
The purpose of this investigation was to
observe the differences between the
photosynthetic rates and photo-protection of
young, red, juvenile leaves of Malosma
laurina, and compare it to young, green
leaves. To accomplish this, the open-system
of Li-6400 XT was brought out into the field
to a shrub of Malosma laurina that was
flourishing and had both red and green
leaves present. Then, data of fluorescence,
photosynthetic rate, and conductance was
taken from both red leaves and green
leaves, and the photosynthetic rates were
compared. Through this investigation, we
were able to quantify that in young, red
leaves, which had anthocyanin, the
photosynthetic rate was lower when
compared to the young, green leaves on the
same plant.
Materials and Methods
21
20
19
18
500
1000
1500
2000
3.5
Bilger, W., & Björkman, O. (1990). Role of the
xanthophyll cycle in photoprotection elucidated by
measurements of light-induced absorbance changes,
fluorescence and photosynthesis in leaves of Hedera
canariensis. Photosynthesis Research, 25(3),
173-185.
2. 
Merzlyak, M. N., & Chivkunova, O. B. (2000). Lightstress-induced pigment changes and evidence for
anthocyanin photoprotection in apples. Journal of
Photochemistry and Photobiology B: Biology, 55(2),
155-163.
3. 
Pratt, R. B., Ewers, F. W., Lawson, M. C., Jacobsen,
A. L., Brediger, M. M., & Davis, S. D. (2005).
Mechanisms for tolerating freeze–thaw stress of two
evergreen chaparral species: Rhus ovata and
Malosma laurina (Anacardiaceae). American Journal
of Botany, 92(7), 1102-1113.
3
2.5
500
2500
1000
1500
2000
2500
2
PPFD (µmol/m s)
2
PPFD (µmol/m s)
FIGURE 1: Shows the linear relationship of green leaves and
the rate of photosynthesis as photons (or sunlight) is increased.
TABLE 1: Summarizes
the data collected out
in the field for both
leaves in one plant of
Malosma laurina
1. 
FIGURE 2: Shows the linear relationship of red leaves and the
rate of photosynthesis as photons (or sunlight) is increased.
Quantum
(µmol m-2 s-1)
Green Leaf – Photosynthesis
(µmol m-2 s-1)
Red Leaf – Photosynthesis
(µmol m-2 s-1)
1000
18.6
2.57
1200
19.5
3.07
1400
20.2
3.47
1600
20.6
3.50
1800
21.1
3.71
2000
21.4
3.85
Discussion
After establishing the linear relationship between the production of photosynthesis and the
amount of photons received by a leaf, we were able to determine the rate of photosynthesis
between a green leaf and a red leaf found in the same plant of Malosma laurina (figure 1 and 2).
Upon further statistical analysis, we decided to execute the Student t-test and compared the two
groups to determine the significance of producing anthocyanins. The Student t-test along with an
ANOVA analysis, under equal variance, gave us a p-value of 0.001, lower than an alpha set at
0.05, making it statistically significant. The statistical analysis allowed for us to accept our
hypothesis, which makes logical sense. Since red leaves tend to have higher anthocyanins, red
pigmentation, they utilize most of their energy protecting themselves from harmful UV light (both
A and B rays) (Pratt et al. 2005). Green leaves can be thought as more mature, which causes
them to utilize the majority of their resources activating the process of photosynthesis. If you look
at the data found in table 1, you can already determine that green leaves are working
significantly harder, approximately 5-6 times harder, to convert light into energy.
Acknowledgements
We would like to thank the Natural Science
Division at Pepperdine University for their
ongoing support during this experiment and
for lending us their equipment. We would
also like to thank Dr. Stephen Davis for his
undivided attention during our initial stages of
planning. We truly hope this experiment
incorporates a big concept the biology of
plants. Thank you!