Unique pattern of R-gene variation within populations in Arabidopsis.
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.
Ding
Jing
J
State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing University, Nanjing 210093, China.
Zhang
Weili
W
Jing
Zhiqiang
Z
Chen
Jian-Qun
JQ
Tian
Dacheng
D
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
D029681:Arabidopsis Proteins; C408688:RPP13 protein, Arabidopsis; C488787:RPP8 protein, Arabidopsis; C089426:RPS2 protein, Arabidopsis