Transcript 3/17 - Utexas

Bonus #2 is due F 3/21
Circadian Rhythms: daily patterns set by light
(northern flying squirrel)
CB 48.25
Action
spectrum of
photosynthesis
CB 10.9
Seedling germination may depend on light
CB 39.18
Phytochrome: a reversible receptor
CB 39.20
http://www.mcdb.ucla.edu/Research/Tobin/research.html
Phytochrome
sets the
circadian
clock
http://www.mcdb.ucla.edu/Research/Tobin/research.html
http://plantsinmotion.bio.indiana.edu/plantmotion/movements/leafmovements/clocks.html (oxalis)
http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/tropisms.html (sunflower tracking)
The molecular identity of the circadian
clock is unknown
http://www.ou.edu/wanglab/Circadian.html
CCA1 is a transcription factor that regulates
some photosynthetic genes.
25 28 31 34 37 40 43 46 49 52 55 57
http://www.mcdb.ucla.edu/Research/Tobin/research.html
Overexpression of
CCA1 in transgenic
Arabidopsis plants
abolished the
circadian rhythms
of several genes
with dramatically
different phases.
http://www.mcdb.ucla.edu
/Research/Tobin/research.
html
Plants were created that lack a functional
CCA1 gene
http://www.mcdb.u
cla.edu/Research/T
obin/research.html
With no CCA1 protein, phytochrome induction of
Lhcb RNA is reduced to 60% of the normal level.
http://www.mcdb.ucl
a.edu/Research/Tobin
/research.html
http://www.mcdb.ucla.edu/Research/Tobin/research.html
http://www.mcdb.ucla.edu/Research/Tobin/research.html
Plants overexpressing
CCA1 had delayed
flowering.
Furthermore, leaf
movement rhythms
were abolished
Hey, want to
swap some
pollen?
I don’t have
any flowers.
I guess I will
have to find
another plant.
I hate when
that happens.
You give really
good pollen.
Plants use day length to synchronize flowering
CB 39.22
The critical period is actually night length
CB 39.22
Phytochrome
regulates
flowering
time
CB 39.23
Hormonal
regulation of
flowering time
Exposed to
flower inducing
photoperiod
CB 39.24
NOT exposed to
flower inducing
photoperiod
CB 36.13
Water moves from
the ground through
roots into the shoot
and out stomata in
the leaves.
What happened to this root?
CB 39.28
•Bonus #2 is due F 3/21
•For W Fraken-plants (CB concept 38.4)