In order to study the molecular events in the interaction between plants and sedentary nematodes, the potential of new molecular techniques should be applied to the best available model system. For reasons briefly described, the cruciferous host Arabidopsis thaliana is the most suitable model plant. Among several sedentary root nematodes infecting Arabidopsis, the sugar beet cyst nematode Heterodera schachtii is the best candidate. Some of the possible approaches to solve questions in the host-parasite interaction by using this unique model system are presented.