Research at the Laboratory of Molecular Biology

Since its origin in 1972, the department of Molecular Biology has made major contributions to the development of molecular biological technology for fundamental and applied research. Over the past three decades students conducting research at our department have found positions in a wide variety of research areas including medical research, plant and animal sciences and biotechnology. Thus, students mastering the molecular technology offered at our department will have a sound basis for future careers in human, animal, and plant sciences.

The department of Molecular Biology has several research groups that are active at different areas of plant (developmental) molecular biology. Their research programs aim to understand fundamental processes of plant biology and to use this fundamental knowledge in applied projects. For this we make use of two inportant model systems; Medicago root nodule development and Arabidopsis root development. Advanced techniques based on fluorescence microscopy are used in many of the ongoing project in order to be able to study processes within cells: this allows us to follow the interaction between proteins (for example between receptor and ligand) in living cells, to determine how and where genes are stored in the nucleus, and to determine the mobility of molecules. A brief description can be found below, for a more elaborate description use the links shown at the right side. Also a quick overview of our B.Sc. and M.Sc. thesis subjects is available.

The research described here is being carried out in collaborations with Dutch and foreign colleagues, so there are also good possibilities for internship projects.

Rhizobium infection and root nodule formation

Legumes comprise one of the most important agricultural taxa worldwide providing a major source of proteins for humans and animals, and nitrogen for soil improvement. Especially for development of sustainable agricultural systems legumes will play a major role, since they are able to establish a symbiotic relation with bacteria. Under nitrogen limiting conditions, the leguminous plants will form root nodules in where the bacteria are hosted and will find the proper conditions to reduce atmospheric nitrogen into ammonia. Rhizobium induced nodule formation on legume roots starts with (1) reprogramming of differentiated root cortical cells in order to form a nodule primordium and (2) infection of the root by the bacteria. For both processes the bacterial secreted signals, named nodulation (Nod) factors play a crucial role. From genetic screens carried out at molecular biology and several other groups, a small set of 8 genes has been identified that are involved in Nod factor perception and signaling cascade. Research now is concentrated on the function of the proteins encoded by these genes and how these proteins interact with other plant components (like receptors, transcription and membrane factors and peptide growth regulators) to induce a nodule meristem and to allow Rhizobium to enter the root and infect cells by forming symbiosomes (specialized membrane compartments. To determine how these crucial genes for nodule formation have evolved, also the function of closely related genes in non-nodulating legume species is studied.