Guus Bakkeren

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Research Interests

Molecular genetic and cell biological understanding of plant-microbial interactions including attributes that make microbes pathogenic such as pathogenicity and virulence factors including fungal mating systems. Plant responses to infection such as recognition and accommodation of biotrophic fungi. Action of effectors that may jam host defence signalling networks, but also effectors that elicit defense and resistance responses (avirulence effectors).

My research program at Agriculture and Agri-Food Canada, Summerland Research and Development Center is geared towards the broader goal of contributing to the efforts to combat biotic stresses in cereal crops. We want to understand plant-pathogen interactions in the leaf rust/wheat & Ustilago hordei/barley pathosystems on a molecular level and focus on finding fungal factors essential for pathogenic development on or in the host that could be targets for highly specific inhibitors. Such sophisticated “fungicides” can be produced in antagonistic microbes, applied as crop dressings or produced in crop plants modified through biotechnology. We are interested in why only certain microbes are pathogenic on certain plants. We want to study genes that therefore can be defined as pathogenicity factors and contribute to host range. Pathogens can be more or less virulent or aggressive upon infection, a phenomenon that is often controlled by the additive effect of many “virulence” or “fitness” genes, more recently identified as coding for effectors. Genetically superimposed on this “basic compatibility” of a pathogen to cause disease, we can sometimes identify single dominant genes that render it non-virulent. These genes have therefore been dubbed “avirulence” genes and are prime targets of research in many laboratories because they are (genetically) interacting with cognate plant host resistance genes and determine whether compatible or incompatible interactions will ensue.

Projects on the wheat leaf rust fungus feature generation of genomic resources such as whole genome sequences and their assembly and annotation, transcriptomes, and comparative analyses among many natural isolates. We exploit these resources for functional genomics, proteomics and the study of avirulence and virulence effectors employing molecular genetic and molecular biological methods. This leads to insight into the disease strategies of the pathogens, and the identification of resistance and susceptibility genes which can be exploited to develop strategies for crop protection.

Our efforts will contribute to the development of germplasm harboring broad-spectrum disease resistance and to more environmentally friendly production of crops. Consumers will benefit directly from the availability of cheaper and healthier products which contain reduced or no pesticide residues, and indirectly from a less polluted environment. Producers will benefit from decreasing dependence on toxic pesticides and more economical and environmentally-sustainable production methods.