Phytochromes - R/FR photoreceptors
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l 300 l 400 l 500 l 600 l 700 l 800 Wavelength (nm) 0 - 0.2 - 0.4 - 0.6 - 0.8 - R Pr ϕ = 0.85 k 1, 660 nm k 2, 660 nm Pfr Pfr Phytochromes - R/FR photoreceptors at equilibrium: d[P fr ]/dt = 0 = k 1λ [P r ] - k 2λ [P fr ] [P fr ]/[P tot ] = ϕ = k 1λ / (k 1λ + k 2λ )
description
Phytochromes - R/FR photoreceptors. Pr. Pfr. Pfr. at equilibrium: d [P fr ]/ d t = 0 = k 1 λ [P r ] - k 2 λ [P fr ] [P fr ]/[P tot ] = ϕ = k 1 λ / ( k 1 λ + k 2 λ ). R. ϕ = 0.85. k 2, 660 nm. k 1, 660 nm. Pfr. Phytochromes - R/FR photoreceptors. Pr. Pr. ϕ = 0.03. FR. - PowerPoint PPT Presentation
Transcript of Phytochromes - R/FR photoreceptors
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
