Project description:Cultivated olive tree (Olea europaea L. subsp. europaea var. europaea) is one of most relevant worldwide-extended crops. Since this plant has a huge effect on the economy of several regions, especially in those located in the Mediterranean basin, all efforts focused on its protection have a great relevance in agriculture sustainability. As all extended crops, olive tree cultivars are under the threat of a wide range of pathogens. Among them, Verticillium dahliae has been in the spotlight in the last decades because the disease caused by this soil-borne fungus (Verticillium wilt) is easily spread and can eventually kill the tree. In this line, many different factors have been studied in order to shed some light on the molecular/genetic mechanisms underlying the Olea europaea-Verticillium dahliae interaction, some of them focused on the gene expression pattern of the host. In this study, the expression pattern of roots from thirty-six O. europaea cultivars with different resistance/susceptibility degree to Verticillium wilt has been analyzed by RNA-Seq. As a result, processes involved in plant defense, transcription and root development have emerged as potential players in the differential response to Verticillium wilt of these cultivars. Additionally, a quite interesting set of 421 genes with an opposite expression pattern in those cultivars showing extreme resistance/susceptibility to Verticillium wilt has been discovered, establishing a solid group of candidates to take into account in future genetic improvement programs.