Location: Cereal Crops ResearchTitle: Genome-wide association mapping identifies SnTox5 in Parastagonospora nodorum
|KARIYAWASAM, GAYAN - North Dakota State University|
|RICHARDS, JONATHAN - North Dakota State University|
|LIU, ZHAOHUI - North Dakota State University|
Submitted to: International Congress on Molecular Plant-Microbe Interactions
Publication Type: Abstract Only
Publication Acceptance Date: 7/14/2019
Publication Date: N/A
Interpretive Summary: .
Technical Abstract: The Parastagonospora nodorum-wheat interaction is comprised of P. nodorum necrotrophic effectors and their corresponding host sensitivity genes. To date, nine such interactions have been identified in this pathosystem and three necrotrophic effectors, SnToxA, SnTox1, and SnTox3 have been cloned and functionally validated. In our research, we collected 198 isolates of P. nodorum representing different wheat growing regions of the United States. Whole genome resequencing was done for all the isolates. Isolates were phenotyped for disease on 24 wheat lines including popular wheat cultivars as well as wheat differential lines carrying single sensitivity genes for individual necrotrophic effectors. Phenotypic data obtained using the differential line for Snn5 (LP29) that confers sensitivity to SnTox5 was used to carry out genome-wide association analysis with the use of 402,612 single nucleotide polymorphisms (SNPs). A single locus was identified to be associated with virulence on LP29. A gene that was predicted to encode a small secreted protein was identified as the strongest candidate for SnTox5. The transfer of a functional copy of SnTox5 into the avirulent isolate Sn79-1087 resulted in virulence on wheat lines harboring Snn5. In addition, mutants of the SnTox5 candidate were developed by deleting the gene in the isolate Sn2000. Both gain-of-function transformants and gene-disruption mutants will be further validated by inoculation and QTL analysis on the LP749 population.