title: Targeting xa13, a recessive gene for bacterial blight resistance in rice.
abstract: Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most serious diseases of rice worldwide. Thirty bacterial blight resistance (R) genes (21 dominant genes and 9 recessive genes) in rice have been identified. They are the main sources for the genetic improvement of rice for resistance to Xoo. However, little is known about the recessive R genes. To clone and characterize the recessive R genes, we fine-mapped xa13, a fully recessive gene for Xoo resistance, to a DNA fragment of 14.8 kb using the map-based cloning strategy and a series of sequence-based molecular markers. Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes (an extensin-like gene and a homologue of nodulin MtN3) and the 5' end of a predicted hypothetical gene. These results will greatly facilitate the isolation and characterization of xa13. Four PCR-based markers, E6a, SR6, ST9 and SR11 that were tightly linked to the xa13 locus, were also developed. These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, 430070 Wuhan, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Chu
authors.forename: Binying
authors.initials: B
authors.lastname: Fu
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Caiguo
authors.initials: C
authors.lastname: Xu
authors.forename: Zhikang
authors.initials: Z
authors.lastname: Li
authors.forename: A
authors.initials: A
authors.lastname: Sanchez
authors.forename: Y J
authors.initials: YJ
authors.lastname: Park
authors.forename: J L
authors.initials: JL
authors.lastname: Bennetzen
authors.forename: Qifa
authors.initials: Q
authors.lastname: Zhang
authors.forename: Shiping
authors.initials: S
authors.lastname: Wang
mesh_terms: D032461:Chromosomes, Plant; D018744:DNA, Plant; D018390:Gene Targeting; D017343:Genes, Plant; D005808:Genes, Recessive; D005819:Genetic Markers; D018745:Genome, Plant; D012275:Oryza / Q000235:genetics* / Q000382:microbiology*; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014974:Xanthomonas / Q000472:pathogenicity*
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers