title: Unique pattern of R-gene variation within populations in Arabidopsis.
abstract: An understanding of the variation pattern in disease resistance (R) genes is essential for its use in breeding programs aimed at neutralizing the threat of pathogens. Although the variation between populations is well known, there is little research about R-gene variation patterns within populations. Here, we investigate the polymorphism at three R-gene loci of 39 individual plants from nine populations of Arabidopsis thaliana. Our data suggest that alleles of each locus from individuals within a local population were either nearly identical, or highly diverse as ones between populations. The vast majority (92.5%) of within-population variation was shared globally, with high levels of allelic diversity (up to 11.7%) and abundant diverse-alleles. This unique pattern of within-population variation at R-loci suggests that individual plants within a population had the great potential to maintain a high level of globally-shared polymorphisms, and that the diversifying selection was the major force maintaining such polymorphisms. Consequently, the shared-polymorphism became recyclable for new R-genes, as the corresponding avirulence re-emerges in pathogen populations.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing University, Nanjing 210093, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ding
authors.forename: Weili
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Jing
authors.forename: Jian-Qun
authors.initials: JQ
authors.lastname: Chen
authors.forename: Dacheng
authors.initials: D
authors.lastname: Tian
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics; D005838:Genotype; D007113:Immunity, Innate / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic
chemical_list: D029681:Arabidopsis Proteins; C408688:RPP13 protein, Arabidopsis; C488787:RPP8 protein, Arabidopsis; C089426:RPS2 protein, Arabidopsis