Identification of parasitism genes from root-knot nematode Meloidogyne incognita using cDNA-AFLP, EST-analysis and GenEST

The root-knot nematode Meloidogyne incognita is an obligatory plant parasite, which has evolved a complex feeding relationship with its host plants. Pharyngeal gland secretions play an important role in the parasitic life cycle of Meloidogyne spp. They are involved in migration through the root system and induction and maintenance of the giant cells. The cDNA-AFLP method is adopted to provide more insight in parasitism genes involved in the plant-nematode interaction. Gene expression pro¿ les of various M. incognita stages differing in pharyngeal gland activity (e.g., eggs, pre-parasitic and parasitic juveniles, adult females) are being compared in a cDNAAFLP procedure based on the restriction enzymes ApoI and TaqI. Genes speci¿ cally expressed in the parasitic stages may represent candidate parasitism genes and will be isolated from gel. The DNA sequences of the isolated fragments will be compared with the M. incognita EST database using the computer program GenEST. Furthermore, the spatial expression pattern of the candidates will be analysed using whole mount in situ hybridisation.