Edinburgh, Scotland, United Kingdom - TAIR

From protein dynamics to physiology: phytochrome
B mediated photomorphogenesis
Plants have evolved a variety of sophisticated mechanisms to respond and adapt
to exogenic factors in their natural environment. Multiple photoreceptors regulate
the plant’s development according to the spectral quality and light intensity. In a
combined experimental and theoretical approach we gain new insights into the
phytochrome B controlled signal transduction system in Arabidopsis thaliana.
By suggesting a multiscale approach we connect the mesoscopic phytochrome
B protein dynamics to the macroscopic response. Using the protein dynamics in
combination with a model for hypocotyl growth, we estimate the relevant dynamic
parameters of the phytochrome pathway and the growth kinetics. We challenge
the model by predicting the fluence rate response behavior for an overexpression
line. Furthermore, we predict from the theoretical considerations that
the hypocotyl length depends on the total phytochrome amount in an algebraic
manner. Using experimentally measured phytochrome levels of different mutants
and the corresponding hypocotyl lengths, we find an excellent agreement
between our theoretical prediction and the experimental results. Hence, our
multiscale approach captures the main features of phytochrome B mediated
photomorphogenesis in Arabidopsis.
92
C41
Saturday 15:45 - 16:00
Systems Biology
Julia Rausenberger1
Andrea Hussong2
Stefa Kircher2
Ferenc Nagy3
Jens Timmer4
Eberhard Schøfer2
Christian Fleck1
1Center for Biological
Systems Analysis
University of Freiburg
2Institute of Biology II
University of Freiburg
3University of Edinburgh
4Institute of Physics
University of Freiburg