Source: MONTANA STATE UNIVERSITY submitted to NRP
PARTNERSHIP: UNTANGLING THE MODES OF RESISTANCE AND AVIRULENCE IN RUST DISEASE OF WHEAT FOR GUIDED DURABLE RESISTANCE AND GERMPLASM DEVELOPMENT
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
Reporting Frequency
Annual
Accession No.
1030504
Grant No.
2023-67014-39625
Cumulative Award Amt.
$799,737.00
Proposal No.
2022-10263
Multistate No.
(N/A)
Project Start Date
Sep 1, 2023
Project End Date
Aug 31, 2026
Grant Year
2023
Program Code
[A1141]- Plant Health and Production and Plant Products: Plant Breeding for Agricultural Production
Recipient Organization
MONTANA STATE UNIVERSITY
(N/A)
BOZEMAN,MT 59717
Performing Department
(N/A)
Non Technical Summary
To ensure food security, agriculture will require crops to withstand diseases caused by pests and pathogens. A better understanding of the genes that control these diseases may enable the breeding of durable resistant cultivars and germplasms. Wheat leaf rust disease represents a significant threat to global wheat production and food security, causing billions of dollars in yearly losses. The most sustainable strategy to reduce such losses by overcoming rust epidemics is to breed effective broad-spectrum disease resistance into wheat. Currently, breeders rely on a 'blind' strategy to identify, breed, and deploy R genes in agriculture without detailed knowledge of the rust disease resistance mechanism ofR genes and the interacting partners. This research will identify five resistance genes and their corresponding effector genes from three rust pathogens.The knowledgeprovides valuable tools for molecular surveillance and early detection of new virulent races, which can inform the deployment of R genes to prevent epidemics.
Animal Health Component
10%
Research Effort Categories
Basic
60%
Applied
10%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121549108170%
2021549104030%
Goals / Objectives
Wheat is a major cereal crop, and the US is one of the world's biggest producers. One of the most damaging wheat diseases is caused by three rust fungi, causing ca. $3.5 billion in annual losses. With climate change, rusts pose an increased threat to wheat production due to the expansion of overwintering areas toward northern and southern latitudes. The most sustainable strategy to reduce such losses is to breed broadly effective resistance into wheat. Our research is to expand our understanding of the functions of wheat rust resistance (R) genes and avirulence (Avr) genes /effectors to drive the development of new approaches for breeding varieties with combined pleiotropic and broad-spectrum resistance to rust pathogens.Our specific objectives of this proposal are:Identify the locus of Lr20/Sr15 and its functions with its matching Avr/effectors conferring pleiotropic resistance against wheat leaf rust and stem rust;Identify the leaf rust resistance gene Lr41 and the corresponding AvrLr41;Characterize the leaf rust and stripe rust Avr proteins AvrLr13 and AvrYr27 recognized by the functional resistance protein analogs Lr13 and Yr27, respectively.The research findings will guide the development of new germplasm with durable multi-resistance gene stacking. Also, the research will enrich our knowledge of wheat-rust interactions and host-pathogen co-evolution. The knowledge will provide valuable tools for molecular surveillance and early detection or even prediction of new virulent races, which can inform the deployment of R genes to prevent epidemics.
Project Methods
1.Long-read genome and transcriptome sequencing plus comparative genomics approaches to identify Lr20/Sr15 and their matching effectors;2. RNA-seq and MutRenSeq approaches to clone Lr41;3. BSMV-mediated overexpression to validate gene functions;4. In plantaco-immunoprecipitation (co-IP) and yeast-two-hybrid assay to study Lr13, Yr27 and their matching effectors

Progress 09/01/23 to 08/31/24

Outputs
Target Audience:Wheat breeders and growers, plant scientists, and students who work in agricultural sciences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project provided training opportunities for two graduate and two undergraduate students. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Assembly of the HiFi long-reads sequencing of CS/Ax 7A with the wheat reference genome Publish Lr41 cloning paper Identify the crucial domains for the direct interaction of Lr41 with Pt64H_023004 effector. Confirm which of the six candidates of AvrLr13 genes is the avirulence gene.

Impacts
What was accomplished under these goals? Objective 1: Identify the locus of Lr20/Sr15 and its functions with its matching Avr/effectors conferring pleiotropic resistance against wheat leaf rust and stem rust Progress: We have just finished PacBio HiFi long-reads sequencing of CS/Ax 7A with 12 SMRT cells and are carrying out reference assembly. In the meantime, we have generated PacBio Iso-Seq data for nine wheat lines, including CS/Ax 7A and Thew, the two wild-type genotypes used in mutagenesis, and seven independent EMS mutants. Analyzing these sequencing data is ongoing as planned. Objective 2: Identify the leaf rust resistance gene Lr41 and the corresponding AvrLr41 We have cloned and confirmed that the Lr41 gene encodes a tandem kinase domain-containing protein. The protein product also harbors C-terminal WD40 repeat domains. This is the first discovery of a kinase containing two tandem kinase domains--WD40 repeat domains--as a race-specific rust resistance protein. Using Yeast-two-hybrid (Y2H), we found a direct interaction of Lr41 with Pt64H_023004 effector. Objective 3: Identification of AvrLr13 and AvrYr27 Six candidates of AvrLr13 genes have been selected from the stripe rust isolates s423 and s646, and cloned into T-DNA binary vector for further testing via Agroinfiltration. Objective 4: Development of germplasm with selected gene combinations based on the research results and diagnostic markers. Eight crosses combining two rust resistance genes have been made.

Publications