title: Statistical inference of selection and divergence of the rice blast resistance gene Pi-ta.
abstract: The resistance gene Pi-ta has been effectively used to control rice blast disease, but some populations of cultivated and wild rice have evolved resistance. Insights into the evolutionary processes that led to this resistance during crop domestication may be inferred from the population history of domesticated and wild rice strains. In this study, we applied a recently developed statistical method, time-dependent Poisson random field model, to examine the evolution of the Pi-ta gene in cultivated and weedy rice. Our study suggests that the Pi-ta gene may have more recently introgressed into cultivated rice, indica and japonica, and U.S. weedy rice from the wild species, O. rufipogon. In addition, the Pi-ta gene is under positive selection in japonica, tropical japonica, U.S. cultivars and U.S. weedy rice. We also found that sequences of two domains of the Pi-ta gene, the nucleotide binding site and leucine-rich repeat domain, are highly conserved among all rice accessions examined. Our results provide a valuable analytical tool for understanding the evolution of disease resistance genes in crop plants.
authors.affiliation: Department of Mathematical Sciences, University of Nevada, Las Vegas, Nevada.
authors.forename: Amei
authors.initials: A
authors.lastname: Amei
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma.
authors.forename: Seonghee
authors.initials: S
authors.lastname: Lee
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma.
authors.forename: Kirankumar S
authors.initials: KS
authors.lastname: Mysore
authors.affiliation: USDA-Agricultural Research Service, Dale Bumpers National Rice Research Center, Stuttgart, Arkansas Yulin.jia@ars.usda.gov.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Jia
mesh_terms: D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D006239:Haplotypes; D008390:Markov Chains; D009010:Monte Carlo Method; D012275:Oryza / Q000235:genetics*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics; D010940:Plant Proteins / Q000145:classification / Q000235:genetics*
chemical_list: D010940:Plant Proteins
keywords: NBS-LRR; Pi-ta; Poisson random field; evolution; resistance gene