The contribution of biotechnology to phytoparasitic nematode control

Several species of phytoparasitic nematodes have evolved complex interrelationships with theirhostsby inducing severe modifications in the morphology of fed cells.Nematode parasitism has progressively evolved from ancestral fungi-dependents to migratory ecto- and then endo-sedentary parasitism. The most complexhost-nematode interaction is associated to the ability of nematodes to modify specific plant cellsto their benefit.The highest expression of this capability has been foundin both cyst and root-knot nematodes whichinduce a specific nurse cell system by modulations of plant gene expression and represent serious pests for the most important crops around the world. The recent characterisation of several parasitism genes specifically expressed within oesophageal gland cells of both cyst and root-knot nematodes suggests that the secreted molecules might serve as virulence factors for successful parasitism. The selection of nematode-resistantcultivars is a major goal in the breeding programs. However, how resistant genes in plants mediates recognition of and defence response to these endoparasites is largely unknown. In parallel with the use of such natural resistances, several biotechnological techniques have been used in order to improve knowledge which could provide the possibility of breeding new cultivars with a more stable resistance.