title: Downy mildew (Pl ( 8 ) and Pl ( 14 )) and rust (R ( Adv )) resistance genes reside in close proximity to tandemly duplicated clusters of non-TIR-like NBS-LRR-encoding genes on sunflower chromosomes 1 and 13.
abstract: Nucleotide binding site-leucine rich repeat (NBS-LRR) proteins are encoded by a ubiquitous gene family in sunflower and frequently harbor disease resistance genes. We investigated NBS-LRR-encoding resistance gene candidates (RGCs) flanking the downy mildew resistance genes Pl ( 8 ) and Pl ( 14 ) and the rust resistance gene R ( Adv ), which map on the NBS-LRR clusters of linkage groups 1 and 13 in sunflower genome. We shotgun sequenced bacterial artificial chromosome (BAC) clones proximal to Pl ( 8 ), Pl ( 14 ) , and R ( Adv ) and identified seven novel non-Toll/interleukin-1 receptor (TIR)-like NBS-LRR RGCs, which clustered with previously identified RGCs of linkage group 13 but were phylogenetically distant from the TIR- and non-TIR-NBS-LRR-encoding superfamilies of sunflower. Six of the seven predicted RGCs have intact open reading frames and reside in genomic segments with abundant transposable elements. The genomic localization and sequence similarity of the novel non-TIR-like predicted RGCs suggests that they originated from tandem duplications. RGCs in the proximity of Pl ( 8 ) and R ( Adv ) were likely introgressed from silverleaf sunflower genome, where the RGC cluster of linkage group 13 is duplicated in two independent chromosomes that have different architecture and level of recombination from the respective common sunflower chromosomes.
authors.affiliation: Institute of Plant Breeding, Genetics and Genomics, The University of Georgia, Athens, GA 30602, USA. eleni.bachlava@monsanto.com
authors.forename: Eleni
authors.initials: E
authors.lastname: Bachlava
authors.forename: Osman E
authors.initials: OE
authors.lastname: Radwan
authors.forename: Gustavo
authors.initials: G
authors.lastname: Abratti
authors.forename: Shunxue
authors.initials: S
authors.lastname: Tang
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Gao
authors.forename: Adam F
authors.initials: AF
authors.lastname: Heesacker
authors.forename: Maria E
authors.initials: ME
authors.lastname: Bazzalo
authors.forename: Andres
authors.initials: A
authors.lastname: Zambelli
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Leon
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Knapp
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D032461:Chromosomes, Plant; D005658:Fungi / Q000472:pathogenicity*; D020440:Gene Duplication; D008040:Genetic Linkage; D005838:Genotype; D006368:Helianthus / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D007113:Immunity, Innate / Q000235:genetics*; D000090263:Leucine-Rich Repeat Proteins; D008969:Molecular Sequence Data; D005810:Multigene Family; D009868:Oomycetes / Q000472:pathogenicity*; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D000090263:Leucine-Rich Repeat Proteins; D010940:Plant Proteins; D011506:Proteins