title: Revealing the importance of meristems and roots for the development of hypersensitive responses and full foliar resistance to Phytophthora infestans in the resistant potato cultivar Sarpo Mira.
abstract: The defence responses of potato against Phytophthora infestans were studied using the highly resistant Sarpo Mira cultivar. The effects of plant integrity, meristems, and roots on the hypersensitive response (HR), plant resistance, and the regulation of PR genes were analysed. Sarpo Mira shoots and roots grafted with the susceptible Bintje cultivar as well as non-grafted different parts of Sarpo Mira plants were inoculated with P. infestans. The progress of the infection and the number of HR lesions were monitored, and the regulation of PR genes was compared in detached and attached leaves. Additionally, the antimicrobial activity of plant extracts was assessed. The presented data show that roots are needed to achieve full pathogen resistance, that the removal of meristems in detached leaves inhibits the formation of HR lesions, that PR genes are differentially regulated in detached leaves compared with leaves of whole plants, and that antimicrobial compounds accumulate in leaves and roots of Sarpo Mira plants challenged with P. infestans. While meristems are necessary for the formation of HR lesions, the roots of Sarpo Mira plants participate in the production of defence-associated compounds that increase systemic resistance. Based on the literature and on the presented results, a model is proposed for mechanisms involved in Sarpo Mira resistance that may apply to other resistant potato cultivars.
authors: Department of Molecular Biology, Aarhus University, 8000 Aarhus C, Denmark. ez.orlowska@gmail.com
authors: Elzbieta
authors: E
authors: Orłowska
authors: Alessio
authors: A
authors: Basile
authors: Izabela
authors: I
authors: Kandzia
authors: Briardo
authors: B
authors: Llorente
authors: Hanne Grethe
authors: HG
authors: Kirk
authors: Cristina
authors: C
authors: Cvitanich
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D018519:Meristem / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000469:parasitology; D008954:Models, Biological; D055750:Phytophthora infestans / Q000472:pathogenicity*; D010935:Plant Diseases / Q000276:immunology* / Q000469:parasitology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000469:parasitology; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000469:parasitology; D018520:Plant Shoots / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000469:parasitology; D015398:Signal Transduction; D011198:Solanum tuberosum / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000469:parasitology
chemical_list: D000890:Anti-Infective Agents; D010936:Plant Extracts; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant