Skip to main content
ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Cereal Crops Improvement Research » Research » Publications at this Location » Publication #410372

Research Project: Improvement of Disease and Pest Resistance in Barley, Durum, Oat, and Wheat Using Genetics and Genomics

Location: Cereal Crops Improvement Research

Title: Molecular cloning of the septoria nodorum blotch susceptibility gene Snn2 in wheat

item SENEVIRATNE, SUDESHI - North Dakota State University
item Zhang, Zengcui
item RUNNING, KATHERINE - North Dakota State University
item Peters Haugrud, Amanda
item SZABO-HEVER, AGNES - North Dakota State University
item SINGH, GURMINDER - North Dakota State University
item ACHARYA, KRISHNA - North Dakota State University
item Fiedler, Jason
item MCLEAN, PHILLIP - North Dakota State University
item Xu, Steven
item Yang, Shengming
item Friesen, Timothy
item Faris, Justin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/14/2023
Publication Date: 1/12/2024
Citation: Seneviratne, S., Zhang, Z., Running, K., Peters Haugrud, A.R., Szabo-Hever, A., Singh, G., Acharya, K., Fiedler, J.D., Mclean, P., Xu, S.S., Yang, S., Friesen, T.L., Faris, J.D. 2024. Molecular cloning of the septoria nodorum blotch susceptibility gene Snn2 in wheat. Meeting Abstract. Poster No. PE0390.

Interpretive Summary:

Technical Abstract: Septoria nodorum blotch (SNB) of wheat is a destructive foliar and glume disease caused by the necrotrophic fungal pathogen Parastagonospora nodorum. The disease is initiated by the recognition of pathogen-produced necrotrophic effectors (NEs) by dominant host sensitivity genes in wheat in an inverse gene-for-gene manner. Multiple host sensitivity genes and NEs have been identified in this pathosystem, and some NEs interact with more than one host sensitivity gene. Snn2, which is located on the chromosome 2DS, is the first host gene that was found to be interacting with the necrotrophic effector SnTox267. The objective of this study is to clone and characterize the Snn2 gene. Towards the molecular cloning of Snn2, a saturated genetic linkage map was constructed using a segregating population of 164 F7:8 recombinant inbred lines. The map was saturated with markers identified through SNP genotyping using the 90K iSelect wheat SNP chip, as well as simple sequence repeat (SSR) markers developed based on whole-genome sequence scaffolds, wheat survey sequences, and the IWGSC RefSeq v1.0 reference genome. A high-resolution map was then developed using an F2 population derived from a cross between the SnTox267-insensitive wheat line BR34 and the SnTox267-sensitive line BG301. Over 10,000 gametes were screened for high resolution mapping, and Snn2 was delineated to a genetic interval of 0.58 cM, which corresponds to a physical segment of 0.96 Mb on Chinese Spring reference genome. A total of 45 high confidence genes were identified in this region, which included eight NB-ARC domain-containing genes and ten protein kinase (PK)-containing genes. Analyses of EMS-induced SnTox267-insensitive mutants and genome-wide association studies indicated that one of the PK-major sperm protein (PK-MSP) genes is a strong candidate for Snn2. CRISPR/Cas9-mediated gene editing revealed that the inactivation of this candidate gene can transform the sensitive wheat variety Bobwhite to become insensitive to SnTox267, confirming it as the Snn2 gene. Currently, a gene complementation experiment is being carried out to further validate the cloning of Snn2. Additionally, work is in progress to characterize Snn2 and other SnTox267-sensitivity genes. The findings of this study increase our understanding of wheat-P. nodorum pathosystem and will help to develop better host resistance against SNB through genetic manipulation.