Full-time postdoctoral researcher (2-year contract) - Mechanism of perception of cyclic lipopeptides from soil bacilli by the wheat plasma membrane

Gembloux Agro-Bio Tech (Gx-ABT), part of the University of Liege (Uliege), is a leader in sustainable development, offering expertise in biological engineering, agriculture, and environment management. Gx-ABT hosts over 1300 students, including 335 PhD candidates, providing an interactive environment for post-graduates and researchers. The TERRA center focuses on future agriculture, with interdisciplinary projects in innovation and crop protection.

Since January 2022, Dr Magali Deleu has led the Molecular Biophysics at Interfaces (LBMI) lab within TERRA, specializing in molecular biophysics and computer-assisted modeling. The lab studies biomolecule-membrane interactions using various biophysical tools. Equipped with spectroscopic tools, calorimetry, and a computer platform, LBMI supports basic biophysics research. With over 20 years of experience, Magali Deleu has developed strong skills in the design of relevant biomimetic membranes to characterize the interactions of the bioactive molecules, among which surfactin, with the lipid components of the cell membrane at a molecular level in order to unravel their biological activities.

The other project contributor, Dr Marc Ongena, from the Microbial Processes and Interactions Laboratory (MiPI) at GxABT is an expert in molecular mechanisms governing biocontrol-related plant host-microbe interactions.He has developed strong skills in analytical biochemistry devoted to the characterization of bioactive bacterial metabolites and has developed bioassays for testing bacterial compounds and specifically lipopeptides like surfactin for their bioactivity in triggering plant immune responses.

Job Description

The postdoctoral researcher will join a dynamic research team focused on the molecular-level understanding of plant defense mechanisms activated by natural molecules. The candidate will work on a defined research project (see detailed research description below) and will actively contribute to designing experiments, generating results, presenting findings at international conferences, and writing scientific articles on the topic. The postdoc will also have the opportunity to assist in writing and submitting project proposals related to the same research theme.

In addition to research activities, the candidate may participate in some teaching responsibilities and will have the opportunity to supervise interns.

The post-doc will be based in Gembloux, Belgium at the heart of the beautiful countryside of Wallonia.

This is an equal opportunity position open to all candidates regardless of gender, ethnicity, nationality or other considerations.

Research description

Cyclic lipopeptides (CLPs) secreted by soil beneficial bacilli, have been shown to be promising candidates for stimulating natural plant defenses. Due to their amphiphilic nature and unlike most elicitors which are perceived via high-affinity membrane protein receptors, CLPs are likely to interact directly with the lipids of the plasma membrane (PM) of plant cells, resulting in dynamic changes in the lipid organization. This may explain why a particular CLP does not have the same impact on different plants, as the composition of the plant PM lipids varies between species.

While new insights into the molecular basis of plant defense-eliciting mechanisms by surfactin (Srf), one bacilli CLP, on Arabidopsis thaliana, a dicot model, was recently obtained by our group (See preprint at: https://www.biorxiv.org/content/10.1101/2023.07.04.547613v2), there is a gap of knowledge on the eliciting activity of Srf and other bacilli CLPs on monocots, as well as on the molecular mechanism of CLP perception by monocot cells.

The general goal of this interdisciplinary project is to investigate, at a molecular level, the capacity of CLPs from Bacillus to be perceived by the PM of wheat, a monocot of high agronomic interest, in relation with their plant defense eliciting activity.

By using a rational combination of plant biological assays with appropriate biophysical analyses on wheat PM, three specific objectives are targeted:

- Identify the activity of each CLP family (Srf, fengycin, iturin) and their synergies on wheat defense stimulation.

- Study the impact of CLPs on wheat PM mechanics and organization.

- Determine the significance of specific wheat PM components/organization in CLP-PM interaction and defense elicitation.

Comparing the results of this project with our recent findings on A. thaliana will provide valuable insights into the varying effectiveness of CLPs in triggering defense mechanisms in dicots and monocots, facilitating their biotechnological application. In addition, this project will strengthen the basic knowledge on the structural organization of wheat PM, barely described so far.

Net salary after taxes and social benefits: approximately € 2950 per month for a full-time position, based on the candidate's personal status.

Profile

The candidate is a motivated scientist who holds a PhD in biophysics or biochemistry with a strong background in fluorescence spectroscopy and imaging, isothermal titration calorimetry, liposomes (LUV, GUV) and other biophysical methodologies to study the effect of external molecules on lipid organization of plasma membranes. Additional expertise in plant biochemistry is also recommended.

The candidate must have good working knowledge of English or French, a strong commitment to scientific research and an excellent academic record.

Furthermore, the following personal characteristics will be appreciated:

- A critical thinker capable of proposing innovative solutions

- Proactive in establishing contacts with experts to solve problems and communicate with other members of different teams

- Aspiring to high-impact scientific output

- Attentive to details

- Demonstrating a pragmatic and efficient attitude

- Maintaining the highest standards of scientific integrity