title: Genome-wide analysis of Carica papaya reveals a small NBS resistance gene family.
abstract: The majority of plant disease resistance proteins identified to date belong to a limited number of structural classes, of which those containing nucleotide-binding site (NBS) motifs are the most common. This study provides a detailed analysis of the NBS-encoding genes of the fifth sequenced angiosperm, Carica papaya. Despite having a significantly larger genome than Arabidopsis thaliana, papaya has fewer NBS genes. Nevertheless, papaya maintains genes belonging to both Toll/interleukin-1 receptor (TIR) and non-TIR subclasses. Papaya's NBS gene family shares most similarity with Vitis vinifera homologs, but seven non-TIR members with distinct motif sequence represent a novel subgroup. Transcript splice variants and adjacent genes encoding resistance-associated proteins may provide functional compensation for the apparent scarcity of NBS class resistance genes. Looking forward, the papaya NBS gene family is uniquely small in size but structurally diverse, making it suitable for functional studies aimed at a broader understanding of plant resistance genes.
authors.affiliation: Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA. bporter@hawaii.edu
authors.forename: Brad W
authors.initials: BW
authors.lastname: Porter
authors.forename: Maya
authors.initials: M
authors.lastname: Paidi
authors.forename: Ray
authors.initials: R
authors.lastname: Ming
authors.forename: Maqsudul
authors.initials: M
authors.lastname: Alam
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Nishijima
authors.forename: Yun J
authors.initials: YJ
authors.lastname: Zhu
mesh_terms: D017398:Alternative Splicing; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics; D001665:Binding Sites; D029441:Carica / Q000235:genetics*; D018744:DNA, Plant / Q000378:metabolism; D044783:F-Box Proteins / Q000235:genetics; D017343:Genes, Plant; D018745:Genome, Plant; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000235:genetics; D016366:Open Reading Frames; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D044783:F-Box Proteins; D009711:Nucleotides; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; C501405:TIR1 protein, Arabidopsis