K (Koen) Varossieau MSc

K (Koen) Varossieau MSc

Externe medewerker

Research conducted by the Laboratory of Nematology is part of the research program of the Graduate School Experimental Plant Sciences (EPS) and C.T. de Wit Graduate School for Production Ecology & Resource Conservation (PE&RC).


Tomato plants harbouring the Solanum pimpinellifolium variant of the extracellular cysteine papain-like protease Rcr3 (Rcr3pim) show enhanced susceptibility to infections by the potato cyst nematode Globodera rostochiensis. The apoplastic effector Gr-VAP1 of G. rostochiensis specifically associates with Rcr3pim of tomato. Gr-VAP1 is structurally similar to venom allergen-like proteins, a conserved group of cysteine-rich secretory proteins present in all parasitic nematodes. Transgenic plants overexpressing Gr-VAP1 are also more susceptible to nematode infections than corresponding wild type plants.

The molecular mechanisms underlying the enhanced susceptibility to G. rostochiensis in plants harbouring the Rcr3pim allele and plants overexpressing Gr-VAP1 are not well understood.  Whole transcriptome analyses suggest that both peptide- and lipid-based signalling pathways may be altered in these plants.

The main objective of my project is to investigate if VAP effectors alter peptide- and lipid-based signalling pathways in plants through their actions on apoplastic papain-like cysteine proteases.