Research focus

Suboptimal growth conditions caused by drought, temperature, salt and pathogen-related stress are leading to worldwide yield losses in cultivated crops. It is anticipated that this problem becomes even bigger in the future, as climatic changes will cause more temperature and drought stress, and, in the meantime, the demand for plants for food, feed and bioenergy is increasing. This has encouraged the development of appropriate breeding strategies targeting adaptation and has made crop stress tolerance a major objective in plant biotechnology research (Vanderauwera et al., 2007).

Oxidative stress or the rise in reactive oxygen species (ROS) levels is associated with a multiple of cellular traumas in probably all living organisms. Increased cellular ROS levels can originate from increased production rates through diverse oxidases and peroxidases or from overaccelerated photosynthetic and respiratory electron transport chains. Like other organisms, plants are harnessed with a large and diversified battery of antioxidant mechanisms to detoxify diverse ROS.
Genetic perturbations of individual genes of the antioxidant network have demonstrated their key roles in keeping cellular ROS levels under control (Mittler et al., 2005). Reactive Oxygen Species have recently emerged as important regulators of plant stress responses (Van Breusegem et al., 2008). 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 (Gadjev et al., 2006). Knowledge on the regulatory events governing ROS signal transduction is however still scratching the surface. Through a combined top-down and bottom-up genomics approach 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-tolerant crops (Tognetti et al., 2010).

A second cornerstone of the group studies the function of metacaspases and their inhibitors in Arabidopsis thaliana (Vercammen et al., 2007).
These cysteine proteases are in analogy with animal caspases primary suspects to regulate or execute plant programmed cell death. We have shown recently that metacaspases, analogous to caspases, show cysteine-dependent autocatalytic processing. Although, in contrast to caspases they show arginine/lysine-specific protease activity (Vercammen et al., 2006).