Head of the Laboratory of Phytopathology




Homepage of P.J.G.M.(Pierre) de Wit

Staff member (WU)

Head of the Laboratory of Phytopathology
Former director of the Graduate School Experimental Plant Sciences (EPS)

Working interests: Plant-Pathogen interactions, Cladosporium fulvum, avirulence, resistance, pathogenicity factors

find the content of this paper on-line at Science via the links below:

Abstract: http://www.sciencemag.org/cgi/content/abstract/1111404v1?ijkey=EKzYX82yvHxic&keytype=ref&siteid=sci

Reprint: http://www.sciencemag.org/cgi/rapidpdf/1111404v1?ijkey=EKzYX82yvHxic&keytype=ref&siteid=sci

 
Molecular basis of plant response to microbial invasion.

For many years we have used the Cladosporium fulvum-tomato pathosystem as a model to unravel the molecular communication between a fungal pathogen and its host plant. The pathogen is an imperfect fungus that penetrates stomata of tomato leaves and grows biotrophically as an endophyte in the intercellular space. In planta, the fungus secretes many small cysteine-rich peptides of which some (the Avr peptides) mediate Cf-dependent defence responses in tomato plants that carry the matching Cf resistance genes. The Cf resistance genes are very effective against C. fulvum and have been introgressed from wild relatives by breeders in commercially grown tomato cultivars since the 1930s. We have cloned four Avr genes (Avr2, Avr4, Avr4E and Avr9) that mediate Cf-dependent resistance in plants carrying Cf-2, Cf-4, Hcr9-4E, and Cf-9, respectively. In addition, we have cloned four Ecp (for extracellular proteins) genes (Ecp1, Ecp2, Ecp4 and Ecp5). The Ecps can also mediate Cf-ECP-dependent resistance in tomato plants carrying the matching genes. However, the Cf-ECP genes have not been cloned yet. The co-evolution between C. fulvum and tomato is poorly understood, but it is believed that the Avr and Ecp genes have played, and still play, an important role in this process. It is anticipated that the Avr and Ecp genes play a role in virulence of the pathogen and that during co-evolution tomato has acquired resistance genes that mediate recognition of the Avrs and Ecps, subsequently followed by active defence responses including the hypersensitive response (HR). In our research programme we focus on (i) the cloning, regulation and functional analysis of Avr and Ecp genes and (ii) the identification of tomato genes that play a role in signal perception and signal transduction leading to compatible (plant is susceptible) or incompatible interactions (plant is resistant).

Research Projects

Targeted proteomics of effector proteins Avr2, Avr4E, Avr9 and Ecp2 of Cladosporium fulvum and their virulence targets in tomato.

Funded by Centre for Biosystems Genomics (CBSG; 2003-2007).
Peter van Esse, Bart P.H.J. Thomma and Pierre J.G.M. de Wit

Adaptation to changing nutritional environments: stress and growth regulation in yeast, plants and plant pathogenic fungi (ACE)

Funded by EU Research Training Network (2003-2005)
Ioannis Stergiopoulos,  Bart P.H.J. Thomma, Matthieu H.A.J. Joosten and Pierre J.G.M. de Wit

Structure and function of Avr and Ecp genes of Cladosporium fulvum

Funded by WU/Centre for Biosystems genomics (CBSG; 2003-2005)
Bart P.H.J. Thomma and Pierre J.G.M. de Wit

Signal perception and transduction in the hypersensitive response pathway in resistant plants

Funded by NWO (2002-2007)
 Pierre J.G.M. de Wit and Matthieu H.A.J. Joosten

Directed proteomics to identify novel steps and regulatory genes in HR signal transduction

Funded by NWO (2002-2006)
Iris J.E. Stulemeijer, Pierre J.G.M. de Wit and Matthieu H.A.J. Joosten

For recent publications follow this link.