1. Department of Molecular Cell Physiology; Vrije Universiteit; De Boelelaan 1087 1081 HV Amsterdam The Netherlands
2. Laboratoire de Biologie Moléculaire des Relations Plantes-Microorganismes, CNRS-INRA; BP 27 31326 Castanet-Tolosan Cedex France
3. Faculty of Science, Division of Chemistry, Department of Biochemistry and Molecular Biology; Institute for Molecular Biological Sciences, BioCentrum Amsterdam, Vrije Universiteit; de Boelelaan 1083 1081 HV Amsterdam The Netherlands