Computational Modeling Reveals Central Parameters for Brassinosteroid-regulated Cellular Processes Linked to Elongation Growth in the Arabidopsis Root

  • 6 October 2022
    4:00 PM
  • University Campus Bohunice (pavilion B11/ seminar room 132)

Lecture will be held in English

Speaker

Prof. Dr. Klaus Harter,

Leader or research group

Plants face the problem that they are confined to their environment and have to endure and adapt to a broad array of environmental conditions. Furthermore, plants have to convert the "diffuse" energy source "light" into biochemical energy and to enrich mineral nutrients during uptake from the soil. To optimize photosynthesis and nutrient supply and, thus, growth and development in a highly competitive environment, plants depend on a multitude of signal perception systems for these endogenous and exogenous signals. Phytohormones, which are also perceived by specific receptors, fulfill a pivotal role in coordinating the responses to environmental cues with those induced by developmental processes. This complex coordination challenge does not lead to stochastic or chaotic reactions but to distinct output responses resulting in well-defined physiological adaptations as well as appropriate growth and development. These responses to a variety of simultaneously incoming exogenous and endogenous stimuli presuppose a kind of signal perception, transduction and processing machinery requiring highly networked molecular integration mechanisms. Although several specific and more-or-less linear signalling pathways have been described for higher plants in recent time, hardly anything is known about the components, composition and molecular mechanisms underlying signal integration.

Our present research focuses on the specific features of plant signal perception, signal transduction and information integration with our main concentration on the processes which are unique for higher plants.


Link to research group of professor Harter.

About the lecture

"Computational Modeling Reveals Central Parameters for Brassinosteroid-regulated Cellular Processes Linked to Elongation Growth in the Arabidopsis Root"

Brassinosteroids (BR) are key hormonal regulators of plant development. However, whereas the individual components of BR perception and signaling are well characterized experimentally, the question of how they do act together and whether they are sufficient to carry out the critical function of cellular elongation remains open. Here, computational modeling with quantitative cell physiology was combined to understand the dynamics of the plasma membrane (PM)-localized, fast BR response pathway during the initiation of cellular responses in the epidermis of the Arabidopsis root tip linked to cell elongation. The model, consisting of ordinary differential equations, comprises the BR induced hyperpolarization of the PM, the acidification of the apoplast and subsequent cell wall swelling. Evidence will be shown suggesting that the competence of the root epidermal cells for the BR response predominantly depends on the amount and activity of H+-ATPases in the PM. The model further predicts that an influx of cations is required to compensate for the shift of positive charges caused by the apoplastic acidification. A potassium channel was subsequently identified and experimentally characterized, fulfilling this function. Thus, a landscape of components and parameters for physiological processes was established that is linked to cell elongation, a central process in plant development. In addition, sptPALM data of the spatiotemporal dynamics of BRI1 and other BR signaling components will be presented which will be integrated for further refinement in our computational model in the future.

 

Registration for lunch with the speaker /for Ph.D. students/

The sponsored lunch usually takes place in the Campus River restaurant. Please meet the speaker and other students at 12:45 at the reception desk at the main entrance (building B22, see the map below).






Loading map…

Loading map…

You are running an old browser version. We recommend updating your browser to its latest version.

More info