title: Comparative analysis of superfamilies of NBS-encoding disease resistance gene analogs in cultivated and wild apple species.
abstract: Eleven distinct families of resistance gene analogs (RGAs) with the characteristic nucleotide-binding sequence (NBS) were identified in two wild apple species, Malus prunifolia and M. baccata, and two cultivated apple cultivars, M. domestica cv. Fuji and M. domestica cv. Hong-ok, using PCR approaches with degenerate primers based on two conserved motifs of known NBS-LRR resistance genes. These RGA families were found to be represented in all the apple species tested, including wild and cultivated species. However, their sequences are very divergent from each other. Furthermore, the low level of recombination detected within their RGA families supports the idea that the evolution of NBS-encoding sequences in apple species involves the gradual accumulation of mutations. Despite the high diversity of the RGA families found in all apple species, the apparent lack of differentiation between wild and cultivated forms suggests that other factors, such as the capacity to tolerate pathogens, might play an important role in the survival of wild-type species.
authors.affiliation: Department of Life Sciences, Ewha Womans University, 120-750 Seoul, Korea. lee@ewha.ac.kr
authors.forename: S-Y
authors.initials: SY
authors.lastname: Lee
authors.forename: J-S
authors.initials: JS
authors.lastname: Seo
authors.forename: M
authors.initials: M
authors.lastname: Rodriguez-Lanetty
authors.forename: D-H
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018744:DNA, Plant / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D017343:Genes, Plant; D014644:Genetic Variation; D027845:Malus / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D018744:DNA, Plant; D004268:DNA-Binding Proteins; D010940:Plant Proteins