title: Defence responses in Rpv3-dependent resistance to grapevine downy mildew.
abstract: The Rpv3 locus determines the ability to operate an isolate-specific hypersensitive response (HR) against Plasmopara viticola in grapevines that carry a resistant Rpv3                         (+) haplotype. Artificial infection was performed on leaf discs of Rpv3                         (+) and Rpv3                         (-) grapevines with two distinct isolates of the pathogen (avrRpv3                         (+) and avrRpv3                         (-)). The plant response, including the establishment of HR and changes in expression of 33 genes, was compared to the development of the pathogen. HR was induced exclusively in the Rpv3                         (+) host upon inoculation with the avrRpv3                         (+) isolate of the pathogen, which is assumed to use avrRpv3                         (+) effectors that are recognised by/through the plant Rpv3                         (+) gene product. The limitation imposed on pathogen growth was the result of inducible responses elicited by the Rpv3                         (+)-avrRpv3                         (+) interaction. This host reaction relied on transcriptional induction of the HR-associated gene HSR1 and salicylic acid-induced pathogenesis-related (PR) genes PR-1 and PR-2 during the initial 24-48 h post-inoculation. These events had no parallel in the Rpv3                         (-) host or upon infection with the avrRpv3                         (-) isolate. The emerging model for Rpv3-mediated defence, which is dependent upon race-specific recognition, associated with up-regulation of PR-1 and PR-2 genes, and enforced by localised HR-type necrosis, is compatible with the cascade of events initiated by the products of NB-LRR and LRR-kinase receptor-like genes, such as those residing in the Rpv3 locus.
authors: Dipartimento di Scienze Agrarie e Ambientali, University of Udine, via delle scienze 208, 33100, Udine, Italy.
authors: Karen
authors: K
authors: Casagrande
authors: Luigi
authors: L
authors: Falginella
authors: Simone Diego
authors: SD
authors: Castellarin
authors: Raffaele
authors: R
authors: Testolin
authors: Gabriele
authors: G
authors: Di Gaspero
mesh_terms: D003517:Cyclopentanes / Q000494:pharmacology; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000276:immunology*; D006239:Haplotypes; D054884:Host-Pathogen Interactions; D009868:Oomycetes / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity*; D054883:Oxylipins / Q000494:pharmacology; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000494:pharmacology; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D013045:Species Specificity; D013997:Time Factors; D015854:Up-Regulation; D014774:Virulence; D027843:Vitis / Q000235:genetics / Q000276:immunology* / Q000382:microbiology / Q000502:physiology
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; C011006:jasmonic acid; D020156:Salicylic Acid