title: A resistance locus in the American heirloom rice variety Carolina Gold Select is triggered by TAL effectors with diverse predicted targets and is effective against African strains of Xanthomonas oryzae pv. oryzicola.
abstract: The rice pathogens Xanthomonas oryzae pathovar (pv.) oryzae and pv. oryzicola produce numerous transcription activator-like (TAL) effectors that increase bacterial virulence by activating expression of host susceptibility genes. Rice resistance mechanisms against TAL effectors include polymorphisms that prevent effector binding to susceptibility gene promoters, or that allow effector activation of resistance genes. This study identifies, in the heirloom variety Carolina Gold Select, a third mechanism of rice resistance involving TAL effectors. This resistance manifests through strong suppression of disease development in response to diverse TAL effectors from both X. oryzae pathovars. The resistance can be triggered by an effector with only 3.5 central repeats, is independent of the composition of the repeat variable di-residues that determine TAL effector binding specificity, and is independent of the transcriptional activation domain. We determined that the resistance is conferred by a single dominant locus, designated Xo1, that maps to a 1.09 Mbp fragment on chromosome 4. The Xo1 interval also confers complete resistance to the strains in the African clade of X. oryzae pv. oryzicola, representing the first dominant resistance locus against bacterial leaf streak in rice. The strong phenotypic similarity between the TAL effector-triggered resistance conferred by Xo1 and that conferred by the tomato resistance gene Bs4 suggests that monocots and dicots share an ancient or convergently evolved mechanism to recognize analogous TAL effector epitopes.
authors.affiliation: Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, 06511, USA. lindsay.triplett@CT.gov.|Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1177, USA. lindsay.triplett@CT.gov.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Triplett
authors.affiliation: Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1177, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Cohen
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, 06520, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Heffelfinger
authors.affiliation: Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA.
authors.forename: Clarice L
authors.initials: CL
authors.lastname: Schmidt
authors.affiliation: Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1177, USA.
authors.forename: Alejandra I
authors.initials: AI
authors.lastname: Huerta
authors.affiliation: Université des Sciences Techniques et Technologiques, Faculté des Sciences et Techniques, LBMA, Bamako, Mali.
authors.forename: Cheick
authors.initials: C
authors.lastname: Tekete
authors.affiliation: IRD, Cirad, Univ. Montpellier, Interactions Plantes Microorganismes Environnement (IPME), Montpellier, 34394, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Verdier
authors.affiliation: Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA.|Plant Pathology and Plant Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Bogdanove
authors.affiliation: Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1177, USA.
authors.forename: Jan E
authors.initials: JE
authors.lastname: Leach
mesh_terms: D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D014974:Xanthomonas / Q000472:pathogenicity*
chemical_list: D010940:Plant Proteins
keywords: Bs4; Carolina Gold Select; Oryza sativa; TAL effector; Xanthomonas oryzae; bacterial leaf blight; bacterial leaf streak