title: Competitive Index: Mixed Infection-Based Virulence Assays for Genetic Analysis in Pseudomonas syringae-Plant Interactions.
abstract: When studying bacterial plant pathogens, the genetic analysis of the contribution of virulence factors to the infection process has traditionally been hindered by their high degree of functional redundancy. In recent years, it has become clear that the use of competitive index in mixed infections provides an accurate and sensitive manner of establishing virulence phenotypes for mutants for which other assays have failed. Such increases in sensitivity and accuracy are due to the direct comparison between the respective growths of the co-inoculated strains within the same infection, each strain replicating as they would in individual infections. Interferences between the co-inoculated strains must be therefore avoided using the appropriate experimental settings. In this chapter, we will present the optimal experimental conditions to achieve maximum sensitivity on virulence assays using the phytopathogenic bacterium Pseudomonas syringae, as well as some additional considerations to ensure the correct interpretations of the results.
authors.affiliation: Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Alberto P
authors.initials: AP
authors.lastname: Macho
authors.affiliation: Dpto. Biología Celular, Genética y Fisiología, Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Campus de Teatinos, Avda. Cervantes 2, Málaga, E-29071, Spain.
authors.forename: José S
authors.initials: JS
authors.lastname: Rufián
authors.affiliation: Dpto. Biología Celular, Genética y Fisiología, Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Campus de Teatinos, Avda. Cervantes 2, Málaga, E-29071, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Ruiz-Albert
authors.affiliation: Dpto. Biología Celular, Genética y Fisiología, Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Campus de Teatinos, Avda. Cervantes 2, Málaga, E-29071, Spain. cbl@uma.es.
authors.forename: Carmen R
authors.initials: CR
authors.lastname: Beuzón
mesh_terms: D060085:Coinfection; D054884:Host-Pathogen Interactions; D010641:Phenotype; D063245:Plant Development; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000254:growth & development / Q000382:microbiology; D010944:Plants / Q000382:microbiology; D044224:Pseudomonas syringae / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors
keywords: Competitive index; Genetic analysis; Immunity; Mixed infection; Resistance; Virulence