Xa21D Encodes a Receptor-Like Molecule with a Leucine-Rich Repeat Domain That Determines Race-Specific Recognition and Is Subject to Adaptive Evolution

• Published in: The Plant cell 1998-05, Vol.10 (5), p.765-779
• Main Authors: Wang, Guo-Liang, Ruan, De-Ling, Song, Wen-Yuan, Sideris, Steve, Chen, LiLi, Pi, Li-Ya, Zhang, Shiping, Zhang, Zhen, Fauquet, Claude, Gaut, Brandon S., Whalen, Maureen C., Ronald, Pamela C.
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; Amino Acid Sequence; Amino acids; Biological Evolution; Dimerization; Disease Susceptibility; DNA; Evolution, Molecular; Family members; Leucine; Ligands; Molecular Sequence Data; Multigene Family; Nucleotides; Oryza - genetics; Oryza - microbiology; Oryza - physiology; Plant cells; Plant Diseases; Plant Proteins - biosynthesis; Plant Proteins - chemistry; Plant Proteins - genetics; Plants; Plants, Genetically Modified; Polymerase Chain Reaction; Protein-Serine-Threonine Kinases - biosynthesis; Protein-Serine-Threonine Kinases - chemistry; Protein-Serine-Threonine Kinases - genetics; Receptors; Receptors, Cell Surface - biosynthesis; Receptors, Cell Surface - genetics; Retroelements; Rice; Sequence Alignment; Transgenic plants; Xanthomonas - genetics; Xanthomonas - pathogenicity
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.10.5.765

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.