title: Eggplant and related species are promising genetic resources to dissect the plant immune response to Pseudomonas syringae and Xanthomonas euvesicatoria and to identify new resistance determinants.
abstract: The apparent lack of durability of many resistance (R) genes highlights the need for the constant identification of new genetic sources of resistance for the breeding of new disease-resistant crop cultivars. To this end, we screened a collection of accessions of eggplant and close relatives for resistance against Pseudomonas syringae pv. tomato (Pto) and Xanthomonas euvesicatoria (Xeu), foliar plant pathogens of many solanaceous crops. Both pathogens caused substantial disease on most genotypes of eggplant and its relatives. Promisingly, however, some of the genotypes were fully or partially resistant to either of the pathogens, suggesting the presence of effective resistance determinants in these genotypes. Segregation of resistance to the growth of Xeu following infiltration in F2 progeny from a cross of a resistant and susceptible genotype suggests that resistance to Xeu is inherited as a multigenic trait. With regard to Pto, a mutant strain lacking all 28 functional type III secreted effectors, and a Pseudomonas fluorescens strain expressing a P. syringae type III secretion system (T3SS), both elicit a strong cell death response on most eggplant lines. Several genotypes thus appear to harbour a mechanism for the direct recognition of a component of the T3SS. Therefore, eggplant and its close relatives are promising resources to unravel novel aspects of plant immunity and to identify new candidate R genes that could be employed in other Solanaceae in which Xeu and Pto cause agriculturally relevant diseases.
authors.affiliation: Department of Plant Pathology, Physiology, and Weed Sciences, Virginia Tech, 537 Latham Hall, West Campus Drive, Blacksburg, VA, 24061, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Clarke
authors.forename: Byron W
authors.initials: BW
authors.lastname: Hayes
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Runde
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Wicker
authors.forename: Boris A
authors.initials: BA
authors.lastname: Vinatzer
mesh_terms: D058947:Bacterial Secretion Systems; D016923:Cell Death; D020090:Chromosome Segregation / Q000235:genetics; D003433:Crosses, Genetic; D060467:Disease Resistance / Q000276:immunology*; D060146:Ecotype; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D057865:Plant Immunity; D044224:Pseudomonas syringae / Q000472:pathogenicity / Q000502:physiology*; D040641:Quantitative Trait Loci / Q000235:genetics; D032323:Solanum melongena / Q000166:cytology / Q000235:genetics* / Q000276:immunology*; D013045:Species Specificity; D014774:Virulence; D014974:Xanthomonas / Q000502:physiology*
chemical_list: D058947:Bacterial Secretion Systems
keywords: EtHAN; Pseudomonas syringae; Solanum melongena; Xanthomonas euvesicatoria; avrptoB; eggplant; type III secretion system (T3SS)