Download - Phytochromes - R/FR photoreceptors
Transcript
FR730 nm
R660 nm
l300
l400
l500
l600
l700
l800
Wavelength (nm)
0 -
0.2 -
0.4 -
0.6 -
0.8 -
R
Pr
ϕ = 0.85
k1, 660 nmk2, 660 nm
PfrPfr
Phytochromes - R/FR photoreceptors
at equilibrium:
d[Pfr]/dt = 0 = k1λ[Pr] - k2λ[Pfr]
[Pfr]/[Ptot] = ϕ = k1λ / (k1λ + k2λ)
FR730 nm
R660 nm
l300
l400
l500
l600
l700
l800
Wavelength (nm)
0 -
0.2 -
0.4 -
0.6 -
0.8 -
FR
PrPr
Pfr
ϕ = 0.03
k1, 720 nmk2, 720 nm
Phytochromes - R/FR photoreceptors
Yet: phyA exhibits strongest effect (growth inhibition) in FR
Distribution of the position of the maximum in the action spectrum
How to construct a far-red light receptor from a red light receptor
X Y
Slightly extended network
I
∅ ∅
IIZ
∅
Low fluence rates
High fluence rates
Realization in planta
Different compartments
k1
k2
PrPn
frBinding of FHY1 Cn
fr
k2
k1
Pnr
k1
k2
Pfr