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This video is a
compilation of time lapse frames taken once an hour over a period of
five days using video cameras and Kujata software developed by Mark
Hyett (University of Virginia; mhyett@std.saic.com) and Steve Kay (Scripps Research
Institute). Plant A and Plant B each represent a different
Arabidopsis
thaliana genotype.
Notice that although the plants are of two different genotypes, the
seed leaves or cotyledons move in almost perfect synchrony. These
seedlings were germinated under a 16:8 LD [16 hours light, 8 hours
dark] regimen then transferred to continuous white light at ZT = 3.00
[3 hours after dawn] at three days old. Data collection started at
about subjective dawn on Day Four.
click image above for more detail
Representative
Graphs for Plant A and Plant B Type Plants
Vertical Leaf Movement
These graphs represent vertical Arabidopsis thaliana leaf movement data taken by video
cameras and computer software over a period of five days. The data
here in red with white fuzzy points are the vertical positions of a
single cotyledon, a seed leaf, fit with a representative curve in
white by Fast Fourier Transform Non-Linear Least Square (FFT-NLLS)
fit analysis. Each peak represents the "up" position of the cotyledon
as the underside of the petiole grows more than the upper side. Each
trough is the "down" position as the upper side of the petiole grows
more than the underside. As the plant itself elongates, the cotyledon
is carried upward, and thus the base y position increases with time.
FFT-NLLS employs software developed by Martin Straume (University of
Virginia; ms3g@virginia.edu) and more fully described in the
following publication: Plautz, J.D., Straume, M., Stanewsky, R.,
Jamison, C.F., Brandes, C., Dowse, H.B., Hall, J.C., and Kay, S.A.
(1997). Quantitative analysis of Drosophila period gene transcription in living animals.
J. Biol. Rhythms 12, 204-217. Carl Strayer (University of Virginia;
cas3s@cms.mail.virginia.edu) wrote a great macro (LMRA) to import
the data generated through Mark's software into Marty's FFT-NLLS
program.
Graphic
representations of circadian [15 - 35 hours] period lengths for
individual seed leaf movement for up to 12 plants [= 24 seed leaves]
per named genotype, with some having more than one period in
circadian range. Each point represents a period length between peaks
like those seen in the fit curve shown in the Vertical Leaf Movement
Data graphs above versus its relative weakness. The closer the
point's relative amplitude [y axis] is to 1, the weaker the rhythm.
The mean period length for Plant A type Arabidopsis thaliana plants is not signifcantly different
from that of Plant B type plants.
Graphic
representations of phase for seed leaf movement circadian rhythms.
Each graph includes the phases for up to 12 plants [=24 seed leaves]
per named genotype, with some having more than one detectable phase.
Each point represents a phase of peaks like those seen in the fit
curve shown in the Vertical Leaf Movement Data graphs above versus
its relative weakness. The closer the point's relative amplitude [y
axis] is to 1, the weaker the rhythm. The mean phase for Plant A type
Arabidopsis
thaliana plants is
not significantly different from that of Plant B type plants.
Leaf Movement
References
- Dowson-Day, M.J. and
Millar, A.J. (1999). Circadian dysfunction causes aberrant
hypocotyl elongation patterns in Arabidopsis. Plant J. 17,
63-71.
- Engelmann, W., Simon, K.
and Phen, C.Y. (1992). Leaf movement rhythm in Arabidopsis
thaliana. Z. Naturforschung 47c, 925-928.
- Hicks, K.A., Millar,
A.J., Carré, I.A., Somers, D.E., Straume, M., Meeks-Wagner,
D.R. and Kay, S.A. (1996). Conditional circadian dysfunction of
the Arabidopsis early-flowering 3 mutant. Science 274,
790-792.
- Millar, A.J.,
Carré, I.A., Strayer, C.A., Chua, N.-H. and Kay, S.A.
(1995). Circadian clock mutants in Arabidopsis identified by
luciferase imaging. Science 267, 1161-1163.
- Schaffer, R., Ramsay, N.,
Samach, A., Corden, S., Putterill, J., Carré, I.A. and
Coupland, G. (1998). LATE ELONGATED HYPOCOTYL, an Arabidopsis gene
encoding a MYB transcription factor, regulates circadian
rhythmicity and photoperiodic responses. Cell 93,
1219-1229.
- Schuster, J. and
Engelmann, W. (1990). Recording of rhythms in organisms using
video-digitizing. In Chronobiology: Its role in clinincal
medicine, general biology, and agriculture. Part B., ed. pp.
389-396.
Acknowledgements
- We thank Mark Hyett,
Steve Kay, Carl Strayer and Martin Straume for computer software
and much great advice. Thanks also to John Poisson for his great
advice and photographic know-how.
These movie pages were
developed by Janet
Painter and Bob
Gross.
More
Classic Plant Movement Videos (from Roger Hangarter, Indiana
University)
Rhythmic
Hypocotyl Elongation and Luciferase Videos (from the lab of Andrew
Millar, University of Warwick, UK)
Rob McClung's
Home Page
updated October 17,
2005
.
