Location: Cereal Crops ResearchTitle: Development of diagnostic molecular markers for the multi-pathogen susceptibility gene Tsn1
|RUNNING, KATHERINE - North Dakota State University|
|SINGH, GURMINDER - North Dakota State University|
|SZABO-HEVER, AGNES - Oak Ridge Institute For Science And Education (ORISE)|
|PETERS HAUGRUD, AMANDA - Oak Ridge Institute For Science And Education (ORISE)|
|SENEVIRATNE, SUDESHI - North Dakota State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/2022
Publication Date: 12/1/2022
Citation: Running, K., Singh, G., Szabo-Hever, A., Peters Haugrud, A., Zhang, Z., Seneviratne, S., Fiedler, J.D., Friesen, T.L., Faris, J.D. 2022. Development of diagnostic molecular markers for the multi-pathogen susceptibility gene Tsn1 [abstract]. Plant and Animal Genome 30 Conference. Poster No. PO0535.
Technical Abstract: The Tsn1 gene confers sensitivity to the necrotrophic effector ToxA, which is produced by necrotrophic fungal pathogens that cause the foliar diseases tan spot, septoria nodorum blotch, and spot blotch. Codominant microsatellite markers that delineate Tsn1 to 351 kb were developed previously, but they are not amenable to high-throughput genotyping (HTG), and their efficacy was not evaluated. Here, the published genome assemblies of fifteen bread wheat, two durum wheat, and one wild emmer wheat accessions were used to compare gene and transposable element content in Tsn1- and Tsn1+ lines, revealing two conserved haplotypes. Because Tsn1 is almost always null in insensitive cultivars, conserved KASP markers suitable for HTG were designed in the closest syntenic region between Tsn1- and Tsn1+ assemblies. The flanking KASP markers delineated Tsn1 to 135 kb and were validated on over 1,500 diverse lines. Phenotyping of the lines revealed that the markers correctly predicted a ToxA insensitive phenotype in 99.13-100% of the accessions. The KASP markers were less effective at predicting a ToxA sensitive phenotype (88.68-94.17%) due to a preponderance of insensitive lines with sensitive marker alleles. Sequencing analysis of Tsn1 from these lines revealed some carried nonfunctional alleles, while others carried the dominant Tsn1 allele. Future expression analysis and genetic mapping will elucidate the nature of the ToxA insensitive status in lines with the Tsn1 allele. The markers presented here could be used for reliable and robust marker-assisted elimination of Tsn1, furthering the development of wheat genetically resistant to multiple pathogens.