Orobanche cumana is an obligate root parasitic plant that infects sunflowers, leading to significant yield losses. Broomrape seeds in the soil germinate only by perceiving molecules produced in the sunflower root exudates. Using the genetic resources of Helianthus, we have identified accessions that induce the germination while others do not. Genetic and genomic approaches will identify candidate genes involved in the biosynthesis of the stimulating molecules. An approach without a priori will also be carried out by fractionation of sunflower root exudates and by analyzing their germination capacity and their molecular composition. We will identify the receptors of the molecules in broomrape using functional biochemical approaches and by analyzing their diversity. In addition to fundamental knowledges, our results will lead to the production of new resistant sunflower varieties and new control methods.