title: A paralog of the MtN3/saliva family recessively confers race-specific resistance to Xanthomonas oryzae in rice.
abstract: Approximately one third of the identified 34 rice major disease resistance (R) genes conferring race-specific resistance to different strains of Xanthomonas oryzae pv. oryzae (Xoo), which causes rice bacterial blight disease, are recessive genes. However, only two of the recessive resistance genes have been characterized thus far. Here we report the characterization of another recessive resistance gene, xa25, for Xoo resistance. The xa25, localized in the centromeric region of chromosome 12, mediates race-specific resistance to Xoo strain PXO339 at both seedling and adult stages by inhibiting Xoo growth. It encodes a protein of the MtN3/saliva family, which is prevalent in eukaryotes, including mammals. Transformation of the dominant Xa25 into a resistant rice line carrying the recessive xa25 abolished its resistance to PXO339. The encoding proteins of recessive xa25 and its dominant allele Xa25 have eight amino acid differences. The expression of dominant Xa25 but not recessive xa25 was rapidly induced by PXO339 but not other Xoo strain infections. The nature of xa25-encoding protein and its expression pattern in comparison with its susceptible allele in rice-Xoo interaction indicate that the mechanism of xa25-mediated resistance appears to be different from that conferred by most of the characterized R proteins.
authors: National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China.
authors: Qinsong
authors: Q
authors: Liu
authors: Meng
authors: M
authors: Yuan
authors: Yan
authors: Y
authors: Zhou
authors: Xianghua
authors: X
authors: Li
authors: Jinghua
authors: J
authors: Xiao
authors: Shiping
authors: S
authors: Wang
mesh_terms: D002503:Centromere / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D005799:Genes, Dominant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D005808:Genes, Recessive / Q000235:genetics*; D005810:Multigene Family; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012463:Saliva / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014974:Xanthomonas / Q000502:physiology*
chemical_list: D010940:Plant Proteins