title: Variation in capsidiol sensitivity between Phytophthora infestans and Phytophthora capsici is consistent with their host range.
abstract: Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins.
authors.affiliation: The Sainsbury Laboratory, Norwich, United Kingdom.
authors.forename: Artemis
authors.initials: A
authors.lastname: Giannakopoulou
authors.affiliation: The Sainsbury Laboratory, Norwich, United Kingdom; Sainsbury Laboratory, Cambridge University, Cambridge, United Kingdom.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schornack
authors.affiliation: The Sainsbury Laboratory, Norwich, United Kingdom; Imperial College, Faculty of Natural Sciences, Department of Life Sciences, London, United Kingdom.
authors.forename: Tolga O
authors.initials: TO
authors.lastname: Bozkurt
authors.affiliation: Institute of Food Research, Food & Health Programme, Norwich, United Kingdom.
authors.forename: Dave
authors.initials: D
authors.lastname: Haart
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Canada.
authors.forename: Dae-Kyun
authors.initials: DK
authors.lastname: Ro
authors.affiliation: School of Chemistry, Cardiff University, Cardiff, United Kingdom.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Faraldos
authors.affiliation: The Sainsbury Laboratory, Norwich, United Kingdom.
authors.forename: Sophien
authors.initials: S
authors.lastname: Kamoun
authors.affiliation: Institute of Food Research, Food & Health Programme, Norwich, United Kingdom; John Innes Centre, Department of Metabolic Biology, Norwich, United Kingdom.
authors.forename: Paul E
authors.initials: PE
authors.lastname: O'Maille
mesh_terms: D005453:Fluorescence; D058507:Host Specificity / Q000502:physiology*; D010838:Phytophthora / Q000502:physiology*; D055750:Phytophthora infestans / Q000502:physiology*; D010935:Plant Diseases / Q000469:parasitology; D012717:Sesquiterpenes / Q000378:metabolism*; D000094162:Phytoalexins
chemical_list: D012717:Sesquiterpenes; C081843:capsidiol; D000094162:Phytoalexins