title: Dynamic evolution of resistance gene analogs in the orthologous genomic regions of powdery mildew resistance gene MlIW170 in Triticum dicoccoides and Aegilops tauschii.
abstract: Rapid evolution of powdery mildew resistance gene MlIW170 orthologous genomic regions in wheat subgenomes. Wheat is one of the most important staple grain crops in the world and also an excellent model for plant ploidy evolution research with different ploidy levels from diploid to hexaploid. Powdery mildew disease caused by Blumeria graminis f.sp. tritici can result in significant loss in both grain yield and quality in wheat. In this study, the wheat powdery mildew resistance gene MlIW170 locus located at the Triticum dicoccoides chromosome 2B short arm was further characterized by constructing and sequencing a BAC-based physical map contig covering a 0.3 cM genetic distance region (880 kb) and developing additional markers to delineate the resistance gene within a 0.16 cM genetic interval (372 kb). Comparative analyses of the T. dicoccoides 2BS region with the orthologous Aegilops tauschii 2DS region showed great gene colinearity, including the structure organization of both types of RGA1/2-like and RPS2-like resistance genes. Comparative analyses with the orthologous regions from Brachypodium and rice genomes revealed considerable dynamic evolutionary changes that have re-shaped this MlIW170 region in the wheat genome, resulting in a high number of non-syntenic genes including resistance-related genes. This result might reflect the rapid evolution in R-gene regions. Phylogenetic analysis on these resistance-related gene sequences indicated the duplication of these genes in the MlIW170 region, occurred before the separation of the wheat B and D genomes.
authors.affiliation: State Key Laboratory for Agrobiotechnology/Department of Plant Genetics and Breeding, China Agricultural University, Beijing, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liang
authors.forename: De-Yun
authors.initials: DY
authors.lastname: Zhang
authors.forename: Shuhong
authors.initials: S
authors.lastname: Ouyang
authors.forename: Jingzhong
authors.initials: J
authors.lastname: Xie
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Wu
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Cui
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: Zi-Ji
authors.initials: ZJ
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.forename: Yong-Xing
authors.initials: YX
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Luo
authors.forename: Jan
authors.initials: J
authors.lastname: Dvorak
authors.forename: Naxin
authors.initials: N
authors.lastname: Huo
authors.forename: Qixin
authors.initials: Q
authors.lastname: Sun
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Gu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Liu
mesh_terms: D001203:Ascomycota / Q000472:pathogenicity*; D032461:Chromosomes, Plant; D018744:DNA, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D019143:Evolution, Molecular; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D005838:Genotype; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers