title: Marker development, saturation mapping, and high-resolution mapping of the Septoria nodorum blotch susceptibility gene Snn3-B1 in wheat.
abstract: Septoria nodorum blotch (SNB), caused by Parastagonospora nodorum, is a severe foliar and glume disease on durum and common wheat. Pathogen-produced necrotrophic effectors (NEs) are the major determinants for SNB on leaves. One such NE is SnTox3, which evokes programmed cell death and leads to disease when recognized by the wheat Snn3-B1 gene. Here, we developed saturated genetic linkage maps of the Snn3-B1 region using two F2 populations derived from the SnTox3-sensitive line Sumai 3 crossed with different SnTox3-insensitive lines. Markers were identified and/or developed from various resources including previously mapped simple sequence repeats, bin-mapped expressed sequence tags, single nucleotide polymorphisms, and whole genome survey sequences. Subsequent high-resolution mapping of the Snn3-B1 locus in 5600 gametes delineated the gene to a 1.5 cM interval. Analysis of micro-colinearity of the Snn3-B1 region indicated that it was highly disrupted compared to rice and Brachypodium distachyon. The screening of a collection of durum and common wheat cultivars with tightly linked markers indicated they are not diagnostic for the presence of Snn3-B1, but can be useful for marker-assisted selection if the SnTox3 reactions of lines are first determined. Finally, we developed an ethyl methanesulfonate-induced mutant population of Sumai 3 where the screening of 408 M2 families led to the identification of 17 SnTox3-insensitive mutants. These mutants along with the markers and high-resolution map developed in this research provide a strong foundation for the map-based cloning of Snn3-B1, which will broaden our understanding of the wheat-P. nodorum system and plant-necrotrophic pathogen interactions in general.
authors.affiliation: Department of Plant Pathology, North Dakota State University, Fargo, ND, 58102, USA.
authors.forename: Gongjun
authors.initials: G
authors.lastname: Shi
authors.affiliation: USDA-ARS Cereal Crops Research Unit, USDA-ARS NPA NCSL, Red River Valley Agricultural Research Center, 1605 Albrecht BLVD, Fargo, ND, 58102-2765, USA.
authors.forename: Zengcui
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: USDA-ARS Cereal Crops Research Unit, USDA-ARS NPA NCSL, Red River Valley Agricultural Research Center, 1605 Albrecht BLVD, Fargo, ND, 58102-2765, USA.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Friesen
authors.affiliation: The University of Sydney PBI-Cobbity, Private Bag 4011, Narellan, NSW, 2567, Australia.
authors.forename: Urmil
authors.initials: U
authors.lastname: Bansal
authors.affiliation: Eastern Cereal and Oil Research Centre, Agriculture and Agri-Food Canada, K.W. Neatby Building, 960 Carling Avenue, Ottawa, ON, K1A 0C6, Canada.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Cloutier
authors.affiliation: Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wicker
authors.affiliation: Department of Plant Pathology, North Dakota State University, Fargo, ND, 58102, USA.
authors.forename: Jack B
authors.initials: JB
authors.lastname: Rasmussen
authors.affiliation: USDA-ARS Cereal Crops Research Unit, USDA-ARS NPA NCSL, Red River Valley Agricultural Research Center, 1605 Albrecht BLVD, Fargo, ND, 58102-2765, USA. Justin.Faris@ars.usda.gov.
authors.forename: Justin D
authors.initials: JD
authors.lastname: Faris
mesh_terms: D001203:Ascomycota / Q000235:genetics; D058431:Brachypodium / Q000235:genetics / Q000382:microbiology; D002874:Chromosome Mapping / Q000379:methods; D020224:Expressed Sequence Tags / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics; D054884:Host-Pathogen Interactions / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009183:Mycotoxins / Q000235:genetics; D012275:Oryza / Q000235:genetics / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology*; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics; D014908:Triticum / Q000235:genetics* / Q000382:microbiology*
chemical_list: D005656:Fungal Proteins; D005819:Genetic Markers; D009183:Mycotoxins; D010940:Plant Proteins
keywords: Disease resistance; Host-selective toxin; Map-based cloning; Molecular marker; Necrotrophic pathogen; Wheat