The Effects of Drought on Arabidopsis Ecotypes  Hunter Soltis, Victor Makali, Allison Poole, and Lucy Monigle

1
The Effects of Drought on Arabidopsis Ecotypes
Hunter Soltis, Victor Makali, Allison Poole, and
Lucy Monigle Wofford College, South
Carolina
Arabidopsis is found in almost every part of the
world. Arabidopsis ecotypes have adapted to
thrive in local environment, with varying
climates and precipitation. Does rainfall affect
the growth of three Arabidopsis ecotypes? The
ecotypes selected were determined by the amount
of precipitation they receive. These ecotypes
are Zloc-1 from Bulgaria, NZ1 from Hamilton, New
Zealand and Can-0, from the Canary Islands,
Spain. The Zloc-1 plant has adapted to a
temperate environment, with regular rainfall
equal to about 65 centimeters per year
(http//www.wordtravels.com). The NZ1 plant has
adapted to the high amounts of precipitation in
its region, with more than 121.9 cm per year
(www.climate-charts.com), while the Can-0 plant
had adapted to thrive in a region with low
precipitation, with average yearly rainfall
rarely exceeding 25.4 cm (www.brittanica.com). If
the plants from the different ecotypes are able
to survive under drought conditions, then the
durability and adaptability of the plant will be
shown.
The experiment produced results that were similar
between all groups, because of the conditions
that were applied to the three different
ecotypes. In the first week, the plants had
similar growth because there was no difference in
the soil, and the effects of the drought did not
have a large effect, which was biologically
unsurprising. The second week was more
biologically interesting, as the effects of both
the drought conditions and the ecotypes
demonstrate their adaptation to the environment
and drought tolerance. Our results supported the
null hypothesis. The Arabidopsis was not
negatively effected by drought conditions, but
instead thrived under excess watering. Our
results confirmed what is already known, that
Arabidopsis can survive under diverse conditions.
For future studies, we recommend that this
experiment be carried out for longer then two
weeks. Drought plants should have been planted in
a less water-saturated soil and watering
conditions need to be consistent. Measurements
for plants with irregular growth (bent or fallen)
could have been taken using a string method.
Effect of Drought on Stem Growth of 3
Arabidopsis Ecotypes
Simulated drought conditions will stunt stem
growth in Arabidopsis.
The graph shows that stem growth was not
negatively affected by drought conditions, but
displayed an adaptability to varied conditions.
Between the ecotypes, there was not much
variability in growth, which was unexpected.
18 seeds of ecotype Can-0 were placed in the soil
of each of two trays, tray C-1, and tray C-2.
This was repeated for ecotype NZ1 into tray N-1
and tray N-2, as well as for ecotype Zloc-1 into
tray Z-1 and tray Z-2. The seeds were germinated
for 2-4 days under a photoperiod of 16hrs
light/8hrs dark. Plants from N-1, Z-1, and C-1
were be the control group. They were watered
every other day. Plants from N-2, C-2, and Z-2
were be under drought conditions, and were not be
watered. All plants were kept under the same
photoperiod of 16hrs light/8hrs dark, with the
temperatures kept between 20 C and 25 C. Stem
lengths were measured once a week with a caliper
or measuring stick.
ANOVA Effect of Drought on Stem Growth of 3
Arabidopsis Ecotypes
www.wordtravels.com www.climate-charts.com
www.brittanica.com
During the first week, condition and ecotype had
little effect on stem growth. During the second
week however, condition and ecotype had
individual effects on the growth, and there was a
significant difference in growth when both
ecotype and condition are taken into account.
We would like to thank G.R. Davis, C.
Abercrombie, their assistants T. Player and A.
Steadman. Our class and the rest of the Biology
Department!
2
The Effects of Seed Depth on Germination and
Plant Survival Morgan Hiler, Carrie Martin, and
Hannah LeirmoeWofford College, South Carolina
All seeds germinated, so there was obviously no
treatment effect on germination ( P-value was 1
Fishers exact test). Seeds planted correctly
beneath the dome of agar did not break the
surface. These results suggest that had the
experiment continued, the plants under the agar
would have eventually died.
Arabidopsis seeds are wind distributed they
germinate and grow where they land on the surface
of soil. In the laboratory to facilitate the
measurement of shoot and root growth the seeds
are grown in agar. As far as we know, there has
been no previous experimentation to determine if
the seeds of Arabidopsis will be able to grow
when planted beneath the surface of the agar or
soil. Using agar we will endeavor to answer this
question.
These results support the original hypothesis
that the seeds planted in both conditions would
germinate however, those seeds planted beneath
the agar were generally not capable of breaking
the surface. Therefore, in the natural habitat of
the Arabidopsis if the seeds are planted rather
than wind distributed the seeds will not be able
to survive. This is because the seeds do not have
enough stored energy to support the plant long
enough for the shoot to break the surface and
begin photosynthesis. The seedlings that broke
the domes surface had a shorter distance,
because they were not placed exactly underneath
the middle of the dome or they moved when the
domes were placed on top of the seeds. There
could be several confounding factors in this
experiment such as the seeds below the agar did
not receive direct light like the seeds on the
surface. Some seeds could fail to germinate at
all.  
Arabidopsis seeds are planted below the surface
of the agar will germinate, but the shoots will
not be able to break the surface of the agar.
Experiment Procedure 1. 14 seeds spaced evenly
across the surface of the agar in the six Petri
dishes. 2. 0.8 agar was used to make 42 small
domes of agar on a flat surface. 3. The domes
were cooled carefully and were removed and placed
on top of the seven seeds in each Petri dish. 4.
Dishes were sealed and labeled 1, 2, 3, 4, 5, and
6. Once sealed, the dishes were placed under a
16 hrs light and 8 hrs dark cycle under
florescent lights. 5. After a week seeds were
checked for germination. 6. After two weeks the
seeds were checked again for any continued
germination and if any of the seeds under the
agar domes had broken the surface.
Week 2 Seed Scan Top to Bottom, Right to Left 1,
2, 3, 4, 5, 6,
(http//www.calstatela.edu/faculty/vllnwth/grow.ht
m)
Week 1 Seed Scan Top to Bottom, Left to Right 1,
2, 3, 4, 5, 6
Thanks to Professors Davis and Abercrombie for
their support and suggestions. Thanks also to T.
Player and A. Steadman
3
The Growth of Shoots in Arabidopsis Plants in
Soil and AgarLeah Odom, Gordon Gulledge, Becka
Dunbar, and Becky GardnerWofford College
It was found that Arabidopsis seedlings have a
longer shoot when grown in soil instead of agar.
On average, the seedlings grown in soil measured
around 7mm while the seedlings grown in agar
averaged only 4mm.
Since most plants are already planted in soils
and not in agar dishes, we think that planting
the seeds in soil will speed up the germination
time. Many times, in research labs, Arabidopsis
are grown in agar. However, a study done by
Robert Eddy and Daniel Hahn from Purdue
University showed that Arabidopsis plants can be
grown in soil. Our experiment is whether soil or
agar would be produce longer shoot lengths in the
Arabidopsis.
These results support the hypothesis that
Arabidopsis seedlings planted in soil grow
significantly longer shoots after two weeks than
seedlings planted in agar.
If Arabidopsis seeds are planted in soil, the
shoot will be longer than if planted on agar
plates.
Arabidopsis plants are found in a wide variety of
environments and conditions. Planting Arabidopsis
seedlings in a laboratory limits the conditions
of growth and does not represent a natural
environment. By planting in seedlings in soil,
you are able to simulate natural environmental
conditions. An advantage of planting the
seedlings in agar is being able to observe the
full growth of the plants. These results show
that soil provides better conditions for
Arabidopsis shoot growth. After comparing the
results of shoot growth in agar and soil, they
support our original hypothesis proving that the
shoot lengths of the Arabidopsis seedlings grown
in soil are significantly longer than those grown
in the agar. This experiment was fairly
simplistic, only observing the germination
percentage and the average shoot length. In
future experiments, it would be more beneficial
to incorporate different temperatures or light
cycles to simulate varied environments. This
would allow the scientist to more accurately
determine the causes of accelerated shoot length
growth.
The graph above shows the shoot length (in mm) of
Arabidopsis plants, after two weeks, grown in
soil and agar. The graph proves that the shoot
length is significantly longer in the seedlings
planted in soil. It can be said that the
treatment of the seedlings has a large impact on
how much they will grow.

1. Ten Arabidopsis thaliana seeds of each Ecotype
   Columbia were planted on the upper edge of the
   agar in each of five different small cups. Each
   cup was designated by a letter and each seed in
   the cup was given a number so that we were able
   to keep track of each plant.
2. Cups covered with saran wrap were placed in a
   vertical position underneath florescent lighting
   on a 16 hour light 8 hour dark photoperiod. This
   was the control group in the experiment.
3. Ten Arabidopsis seeds were also placed in each of
   5 soil filled cups covered in saran wrap with the
   exact same photoperiod.
4. The humidity levels of both the soil and the agar
   plates were kept as similar as possible by
   covering each of the cups with saran wrap.
5. The seeds were observed once a week on Wednesday
   over a period of two weeks. On the first Week, we
   recorded germination rates of the plants and on
   the second week we measured the shoot length of
   each of the 100 plants.
6. After measuring the shoot length and recording
   the germination rates, we were able to use the
   SPSS program to run analysis of our experiment.

Part I Effects of Soil vs. Agar on Germination
Seeds germinated equally well on soil and in
agar. (P0.176, Fischers exact test) (data not
shown). We have no statistically significant
evidence that germination rate is associated with
treatment.
Part II Effects of Soil vs. Agar on Shoot
Length
Arabidopsis grown in soils shoots grew
significantly longer than those grown on agar.
(P.000, ANOVA, Fdf1,7231.16)
The authors are indebted to G.R.. Davis for help
with data collection and to C.L. Abercrombie for
help with statistical analysis.
4
The Effects of Oil Contamination on Development
of Arabidopsis Matt Steelman, Josh Fester,
Tinus Van Wyk, and Nicole SowersWofford College,
South Carolina
Some Arabidopsis ecotypes such as those from
Ireland and Bulgaria are known to grow on
roadsides where petroleum runoff could affect
their growth. In an experiment using just
phenanthrene as the pollutant, the Arabidopsis
plants were shown to be negatively affected. We
desired to perform a similar experiment using
basic petroleum to see the effect of this on
plants in our world today. This desire is based
on the real-world problem that is pollution.
The results of our experiment served to support
our alternate hypothesis that an increased
concentration of oil in the agar would stunt the
growth of the root. Although there was a small
increase in growth from 0 oil to 0.1 oil, this
increase is not significant enough to disprove
the alternate hypothesis. Implications of This
Experiment The results of this experiment provide
large implications for the natural world. Today,
society deals with multiple forms of pollution
which are destructive to the world we live in.
This experiment shows that pollution in the soil
due to oil spills, emissions, etc., will prove
detrimental to plant life on earth. Therefore,
we must find ways to avoid significant use of oil
and, if nothing else, to prevent disasters such
as oil spills from occurring within our society.
Future Experiments We recommend that future
experiments find a more effective way to measure
the root such as taking it out of the agar. Also,
the experimenter must make sure that light is
evenly distributed to each agar plate. The next
step to this experiment could be to find the
lethal concentration of oil for this plant.
Germination Overall, germination was unaffected
by increased concentration of oil dissolved in
the agar (p0.667, ?2 with 6 degrees of freedom
4.08).
Root Growth Overall, root growth in the plant
decreased as the concentration of oil in the agar
increased (p0.001, Analysis of Variance FdF 3,
70 6.054
The Addition of petroleum into the agar for
Arabidopsis thaliana ecotype Columbia will
significantly stunt the growth of the plants
root.
Root Growth vs. Concentration
In order to complete this experiment, we will
need the following items Four agar plates such
as used in our lab over the past two weeks 1. 8
agar plates 2. 40 Arabidopsis (ecotype-
Columbia) seeds 3. 5w-30 motor oil 4. Image J
Software 5. Agar 6. Fluorescent Grow
Lights Prior to the actual planting of the
Arabidopsis, we had to mix 0.01, 0.1, and 1
petroleum in agar. We used these concentrations
to see how growth is affected by the amount of
pollution present in the soil. We limited the
highest concentration to 1 in order to lower the
risk of potential destruction of the plant
entirely. Once this was done, we planted 10
seeds of Arabidopsis in each of four agar plates.
We planted these seeds at the upper edge of the
agar on each of the plates. The seeds were
planted in a horizontal line , and the plates
were sealed and placed vertically beneath grow
lights throughout the experiment. One plate
acted as the control group, and the other three
had the variant concentrations of the petroleum
product. Each of the plates had equal
photoperiods, which were 16 hours of light and 8
hours of darkness. We produced this light cycle
by setting a timer for the fluorescent light in
the lab. We allowed them to germinate and mature
over a period of two weeks and we measured the
length of the shoots each week. The root length
was measured using Image J software. These
measurements provided the results for our
experiment.
Special thanks to Dr. Davis and Dr. Abercrombie
for their assistance. Also, thanks to Andy
Steadman and Thomas Player.
1) Lui, Hong. An oxidative stress response to
polycyclic aromatic hydrocarbon exposure is
rapid and complex in Arabidopsis thaliana. Plant
Science Vol. 176 Issue 3 March 2009 pg. 375-382.
5
The Effects of Agar Composition on Root
Development in Arabidopsis thalianaMatthew
Boggs, Aaron Seigler, James SkinnerDepartment of
Biology, Wofford College, Spartanburg, SC 29303
Agar composition did not significantly affect
root growth in the Arabidopsis thaliana
(Columbia).
Agar, a gelatinous substance derived from red
algae, is commonly used at a concentration of
0.8 to grow Arabidopsis plants in the
laboratory. To determine whether this is the
optimal agar concentration for root growth, we
tested in 0.8, twice that at 1.6, and half at
0.4. The Arabidopsis thaliana ecotype Columbia
was used for the experiment as its not from a
region with extreme weather conditions.
The 1.6 agar produced some of the longest
roots, but statistical evidence showed no
advantage among the different agar
compositions. The fragile state of the 0.4 agar
was another problem. The consistency of the 0.4
was so watery that it was difficult to measure
root length because the plants were floating
around in the dish. An unequal distribution of
light over the plants also could have created
skewed results. For the first week of the
experiments, the agar dishes were laid out in
such a way that the 0.4 and 1.6 dishes received
more light than the 0.8 dishes. The problem was
corrected for the second week, but the uneven
light distribution could have provided an unfair
advantage for the 0.4 and 1.6 dishes. While
there was no significant advantage for any of the
compositions, the statistical cutoff was almost
crossed by the data. A larger sample size would
be more appropriate given our hypothesis.
The greater the density of an agar solution that
Arabidopsis thaliana (Columbia) seeds are
cultivated in, the longer the roots.
Materials 1. 6 square agar plates 2. 48
Arabidopsis seeds (Columbia) 3. 1 set of grow
lights 4. 0.40 agar for two dishes (Control
Group) 5. 0.80 agar for two dishes 6. 1.60
agar for two dishes 7. Tape 8. Marker 9. Agar
Plate Rack 10. Caliper   Methods 1. Three
compositions 0.40, 0.80, and 1.60. 2. Two
dishes with 0.40. 3. Two dishes with 0.80. 4.
Two dishes with 1.60. 5. 8 seeds placed in
upper edge of each agar plate. 6. Dishes sealed
and marked accordingly. Marked with small numbers
to not obstruct measurements. Tape that sealed
the dishes was placed in a position that did not
inhibit measurement. 7. Dishes were placed under
growth lights in vertical positions on an agar
rack. Dishes went under light cycle of 16 hour
days and 8 hour nights. 8. Measurements of root
length were taken with Image J software over a 2
week period, once a week.
Agar concentration had no effect on germination
rate (p0.262, Pearson Chi Squared Test
df25.259.) data not shown
The authors are indebted to the tireless work of
G. R. Davis and Ab Abercrombie G. R. Davis for
providing the resources and leadership necessary
for this experiment and Ab Abercrombie for his
assistance with the statistical analysis for the
results.
Agar concentration had no statistical effect on
root growth at 2 weeks (p 0.062, Repeated
measures analysis of variance, DF2, 29 F 3.06)
6
Effects of LED and Fluorescent Lights on Growth
of Arabidopsis Kevin OQuinn, Mesha Arant,
Jordan Ball, and T.J. WhiteDepartment of
Biology, Wofford College, Spartanburg, SC 29303
Different types of lights have been used to
increase the growth of various plants. Our
experiment tested whether LED or fluorescent
lights produce plants with larger root length and
higher germination rates. Fluorescent lights,
which emit heat, some noise, and consume more
energy, and use light that is not as
concentrated as the light of the LED lights. LED
lights use about 10 of the energy of fluorescent
lights, are a more concentrated light source, and
can last for a significant number of years more
than the fluorescent lights.
Plants that were grown under LED lights (n24)
had smaller root lengths than plants that were
grown under fluorescent light (n24). The
germination rate, not shown, was not
statistically relevant (Chi-square (dF1)0.137
p.712). After looking at the growth rate from
Week 1to Week 2, we found, using a
variable-selection procedure and found that root
length yielded the best results. Analyzing the
variable using Fdf1,3611.8 p.002. with this
we concluded that the Fluorescent lights grew the
roots of the Arabidopsis longer than the LED
light panel.
LED growing plates will allow the plants to grow
quicker and larger. The percent germinated will
be greater under the LED growing lights rather
than underneath the florescent lights.
LED growing plates did not produce plants with
longer root lengths nor higher germination rates.

• Materials
• 48 Arabidopsis seeds
• Growing Plates
• Fluorescent Growing Lights and LED Growing Plates
• Agar
• Pipettes
• Tape
• Methods
• 0.8 Agar was placed into 6 growing plates and
  were left to set. Three plates were designated
  for the LED lights, and three were designated for
  the fluorescent lights.
• 8 seeds were placed in each growing plate.
• The plates were sealed and placed in a vertical
  position under the LED and Fluorescent lights.
  The distance from the lights to the plants was
  33.65cm.
• They were maintained with a photoperiod of 16
  hours of light and 8 hours of darkness each day.
  Germination rates and root length were measured
  each week of the experiment.

Our experiment showed that fluorescent lights
produced plants with longer roots than the LED
light panel. The size of the roots that were
grown by the Fluorescent lights had a
considerable size advantage over the LED lights.
Of course, one of the drawbacks of the
Fluorescent lights is that they require a lot
more energy to work than the LEDs. The LEDs use
only about 10 of the energy of the Fluorescent.
One of the things that might have affected the
results was the height from the light source to
the plants. Because the LED panel consisted of
blue and red diodes, the chance that moving it
either closer or farther from the plants may have
optimized the productivity of the light panel.
Either way, in this experiment, the Fluorescent
lights grew the roots longer than the LED light
panel.  
The chart shows the average growth of the roots
of the two treatment groups. Along the x-axis is
the treatment while on the y-axis is the length
it grew. The circles show the average length
while the error bars show 95 confidence
intervals.