Oxidative Stress Signalling

Reactive Oxygen Species (ROS), causing oxidative stress, were long considered as harmful by-products of (diseased) metabolism. However, recently they have emerged as important regulators of plant stress responses. Perturbation in ROS production and/or scavenging are sensed by plant cells as a ‘warning’ message, and genetic programs leading to stress acclimation or cell death are switched on. Knowledge on regulatory events during ROS signal transduction is now only scratching the surface. Through combined top-down and bottom-up genomics and proteomics approaches we are dissecting the gene network governing ROS signal transduction in plants and pinpoint genes that are potential candidates for innovative molecular breeding strategies to develop stress-resilient crops.

Organellar Signaling

Why a focus on retrograde signaling in plants? Biological systems must respond rapidly to both external and internal stimuli to maintain homeostasis, and repair damage. To allow rapid responses, biology often relies on post-translational modifications of specific proteins to effect changes in activity, function, localization, or stability of pre-existing proteins. Several studies have shown that chloroplast and mitochondrial functions are direct target of stresses, from changes in the proteome, altering organellar abundance or modification of large-scale changes in the transcriptome. To mount a fast and dynamic response, retrograde signals are generated in the mitochondria and chloroplasts, finally leading to changes in gene expression. Today, we can barely grasp the mechanism(s) of the communication between the organelles and the nucleus. The main question is how the nucleus gets the message through and are conserved mechanisms in place? A.o. in the FWO-FNRS funded ReACTs project we study redox-dependent retrograde signaling in two (molecular) model plant systems: the green microalga, Chlamydomonas reinhardtii, and the land plant, Arabidopsis thaliana. https://eos-reacts.wixsite.com


Proteases are enzymes that cleave peptide bonds of other proteins. Their omnipresence and diverse activities make them important players in protein homeostasis and turnover of the total cell proteome as well as in signal transduction in plant stress responses and development. To understand protease function, it is of paramount importance to assess when and where a specific protease is active and which substrates they cleave. We mainly focus on the functional analysis of metacaspases, distant relatives of the metazoan caspases, found in plants, fungi, and protists.