Allison Tielking's Poster for the 2015 St. Louis Honors Science Competition

1. RESEARCH POSTER PRESENTATION DESIGN © 2012
www.PosterPresentations.com
Because MMF1 appears to play an important role in regulating growth, it would be
interesting to explore whether plants with varying MMF1 levels grow to a different
size in adulthood. Would manipulating MMF1 levels cause plants to grow bigger? One
could use the exact same setup to measure adult plant growth on soil and compare it
to that of seedlings. This is a very flexible system that could be employed to
quantify growth rates of different plants with different architectures.
Also, since MMF1 is conserved in several crop species, our data suggest that
manipulating MMF1 levels may be a potential target for altering crop growth.
Plants grow with daily rhythms and the acceleration of
growth occurs at certain times of day. They respond to
different environmental conditions, such as light. In
order to fully understand growth differences, one must
measure changes in growth rate over the day.
Abstract
Experimental Design and Objectives
The figure above depicts the growth rates of
different plants Starting at the third night, there is
clear increase in growth rate of mmf1 mutant plants
(red line) compared with that of the wild type plants
(WT, black line). The sample size per line ≥ 14. Error
bars represent Standard Error. This is one
representative of three biological replicates.
Results
Creating A Script to
Coordinate Illumination and
Photography
#!/bin/bash
sudo /usr/local/bin/gpio mode 0 out
#This internally sets the gpio pin to be an output pin.
sudo /usr/local/bin/gpio write 0 1
#This turns the gpio pin 0 to 3.3 volts relative the
ground.
sleep 0.25
#This sleeps the Pi for .25 seconds before taking the
photo.
raspistill -o /home/pi/camera/$(date +"%Y-%m-
%d_%H%M%S")nusinowlab.jpg -vf -hf$
#This takes the photo, horizontal and vertical flip, saves
in camera folder
sleep 0.25
#Pi sleeps for another .25 seconds after photo is taken
sudo /usr/local/bin/gpio write 0 0
#This turns the gpio pin 0 back to ground level (0.0 Volts)
Materials and Methods Conclusions
1. The Raspberry Pi system can be effectively used to coordinate the illumination
and acquisition of time lapse data of seedling growth.
• More cost-effective.
• Compact: one can afford to use multiple palm-sized Pi systems to increase
the sample size.
2. Compared to prior setups with asynchronous imaging and illumination, all images
are retained.
• Synchronized illumination and imaging minimize the heat effect generated by
light exposure.
• My system also reduces the possibility of equipment-caused data loss.
3. By measuring the growth rates of different lines expressing varying amounts of
MMF1, I found that MMF1 quantitatively alters growth rate mainly during the
evening of each day.
• Lowering MMF1 levels (in mmf1 mutant plants) increased growth rate during
the evening.
• Increasing MMF1 levels (in OX3 plants) decreased overall growth rate.
References
Borevitz, J., Neff, M., Phenotypic Analysis of Arabidopsis Mutants: Hypocotyl Length, Cold Spring Harb. Protoc. (2008).
Chory, J., Chatterjee, M., Cook, R.K., Elich, T., Fankhauser, C., Li, J. et al., From seed germination to flowering, light controls plant
development via the pigment phytochrome. Proc. Natl. Acad. Sci. USA 93, 12066-12071 (1996).
Hsu, P.Y., Harmer, S.L., Wheels within wheels: the plant circadian system. Trends in Plant Science (2013).
Nozue, K., and Maloof, J. N., Diurnal regulation of plant growth. Plant Cell Environ., 29, 396–408 (2006).
Nozue K, Covington MF, Duek PD, Lorrain S, Fankhauser C, Harmer SL, and Maloof JN., Rhythmic growth explained by coincidence between
internal and external cues. Nature, 448, 358-361 (2007).
Nusinow, D.A., Helfer, A., Hamilton, E.E., King, J.J., Imaizumi, T., Schultz, T.F. et al., The ELF4–ELF3–LUX complex links the circadian clock to
diurnal control of hypocotyl growth. Nature 475, 398–402 (2011).
Detailed Procedure
Anyone interested in determining plant growth rate using our system can find a
detailed procedure on the assembly and use of our system at
http://maker.danforthcenter.org/
Allison Tielking1, He Huang2, Rebecca Nolan2, Dmitri A. Nusinow2
1Mary Institute and St. Louis Country Day School, 2Donald Danforth Plant Science Center, St. Louis, MO
Monitoring diurnal growth rates of plants using a low-cost, open-source imaging system.
Current imaging systems use sophisticated cameras and light sources, which can cost
close to $5,000. In this poster, I am going to present a cost-effective ($200) time-
lapse imaging system. The system utilizes a microcomputer called Raspberry Pi and
functions just as well as the aforementioned systems do. I configured the system
and wrote a computer program to synchronize the infrared light illumination and
image capture by the camera. In addition to the low cost, my system also has a very
compact size and all driven autonomously. It is networked, allowing for remote data
acquisitions and can be assembled with relative ease.
The image sequence above shows the accumulated growth of one mmf1 mutant
plant over 96 hours after germination (h.a.g.). A total of 80 images were taken for
that single plant, starting at 24 h.a.g. to monitor its growth.
10396724824 h.a.g
Using a MOSFET Transistor to
Control 12V Power LED Light
Array with the Raspberry Pi
The complete imaging system set up in
the growth chamber.
Performing Data Analysis using
the ImageJ software
Future Directions
Time
Design a low-cost
imaging system with a
compact size that can
do accurate
measurement of plant
growth rates.
The Nusinow lab identified a new plant mutant (mmf1)
of the MMF1 gene, which grows longer hypocotyls
(juvenile stems) than wild type. The OX3 overexpresses
MMF1, and L7 is the rescue line. Backing up these
qualitative observations requires continuous monitoring
growth rates of plants in a variety of conditions,
including dark. By using infrared LED lights, people can
take images of plants in the dark.
Using this system, we determined that the mutant mmf1 plants had increased
relative growth rate specific at night compared to wild type plants. Our data suggest
that MMF1 controls plant growth during the dark period of day.
Pi
Identify a light wavelength
that can be used for
imaging at night and does
not alter plant responses.
Quantify daily growth
and determine the
underlying differences
in growth rates between
various plant lines using
time lapse imaging.
Raspberry Pi microcomputer and camera
that can detect light in near infrared
wavelength (800-1000 nm) (upper)
Acknowledgements
This work was supported by Donald Danforth Plant Science Center Start-up Funds and
a grant from the Raspberry Pi Foundation.
880 nm LED light
array
Light diffuser
Problem/Question: What genes regulate the daily growth rhythms in plants?
Working Hypothesis: The MMF1 gene regulates hypocotyl growth, particularly during the
nighttime.
IV: Hours after germination, various plant lines
DV: Growth rate in mm per hour
Controls: seed environment, procedure, L7 (rescue) and WT lines, length of data
collection
Camera
Plate w/
seedlings
LED array
Snap one picture per hour
I imaged for about 4 and a half days after
germination- which I determined as when
the seedling visibly emerged from the seed
After I measured the hypocotyl length of each seedling at each time point, I took the first
derivative of the data to determine the growth rate in mm per hour, resulting in this graph.
Night
Day