title: Genetic architecture and pleiotropy shape costs of Rps2-mediated resistance in Arabidopsis thaliana.
abstract: The mounting evidence that R genes incur large fitness costs raises a question: how can there be a 5-10% fitness reduction for all 149 R genes in the Arabidopsis thaliana genome? The R genes tested to date segregate for insertion-deletion (indel) polymorphisms where susceptible alleles are complete deletions. Since costs of resistance are measured as the differential fitness of isolines carrying resistant and susceptible alleles, indels reveal costs that may be masked when susceptible alleles are expressed. Rps2 segregates for two expressed clades of alleles, one resistant and one susceptible. Plants with resistant Rps2 are not less fit than those with a susceptible Rps2 allele in the absence of disease. Instead, all alleles provide a fitness benefit relative to an artificial deletion because of the role of RPS2 as a negative regulator of defence. Our results highlight the interplay between genomic architecture and the magnitude of costs of resistance.
authors.affiliation: Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Alice
authors.identifier: 0000-0002-4606-1832
authors.initials: A
authors.lastname: MacQueen
authors.affiliation: Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Joy
authors.initials: J
authors.lastname: Bergelson
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D056084:Genetic Fitness; D058685:Genetic Pleiotropy; D010935:Plant Diseases / Q000276:immunology*; D057865:Plant Immunity / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D029681:Arabidopsis Proteins; C089426:RPS2 protein, Arabidopsis