title: Xa21D encodes a receptor-like molecule with a leucine-rich repeat domain that determines race-specific recognition and is subject to adaptive evolution.
abstract: The rice Xa21 gene confers resistance to Xanthomonas oryzae pv oryzae in a race-specific manner. Analysis of the inheritance patterns and resistance spectra of transgenic plants carrying six Xa21 gene family members indicated that one member, designated Xa21D, displayed a resistance spectrum identical to that observed for Xa21 but conferred only partial resistance. Xa21D encodes a receptor-like protein carrying leucine-rich repeat (LRR) motifs in the presumed extracellular domain. The Xa21D transcript terminates shortly after the stop codon introduced by the retrotransposon Retrofit. Comparison of nucleotide substitutions in the LRR coding regions of Xa21 and Xa21D provided evidence of adaptive selection. Both functional and evolutionary evidence indicates that the Xa21D LRR domain controls race-specific pathogen recognition.
authors.affiliation: Department of Plant Pathology, University of California at Davis, 1 Shields Avenue, Davis, California 95616, USA.
authors.forename: G L
authors.initials: GL
authors.lastname: Wang
authors.forename: D L
authors.initials: DL
authors.lastname: Ruan
authors.forename: W Y
authors.initials: WY
authors.lastname: Song
authors.forename: S
authors.initials: S
authors.lastname: Sideris
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: L Y
authors.initials: LY
authors.lastname: Pi
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: C
authors.initials: C
authors.lastname: Fauquet
authors.forename: B S
authors.initials: BS
authors.lastname: Gaut
authors.forename: M C
authors.initials: MC
authors.lastname: Whalen
authors.forename: P C
authors.initials: PC
authors.lastname: Ronald
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D005075:Biological Evolution; D019281:Dimerization; D004198:Disease Susceptibility; D019143:Evolution, Molecular; D007930:Leucine; D008969:Molecular Sequence Data; D005810:Multigene Family; D012275:Oryza / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D010935:Plant Diseases; D010940:Plant Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D018626:Retroelements; D016415:Sequence Alignment; D014974:Xanthomonas / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D010940:Plant Proteins; D011956:Receptors, Cell Surface; D018626:Retroelements; C097148:Xa21 protein, Oryza sativa; D017346:Protein Serine-Threonine Kinases; D007930:Leucine