Location: Plant Science Research
Project Number: 5062-30100-001-004-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 30, 2025
End Date: Sep 29, 2030
Objective:
1.1. Coordinate a multi-site bacterial leaf streak of wheat testing nursery.
1.2. Curate and expand a collection of Xanthomonas translucens strains.
1.3. Generate whole-genome annotated assemblies for representative X. translucens strains.
1.3. Coordinate an annual bacterial leaf streak stake-holder meeting.
2.1. Develop fluorescent stress-reporter wheat lines to identify infected cell types and monitor disease progression.
2.2. Optimize enrichment sequencing protocols to maximize sequence coverage at target loci in the large and complex wheat genome.
2.3. Determine DNA methylation changes over the course of disease to identify novel breeding targets
Approach:
Uniform testing nurseries for evaluating released and unreleased spring wheat varieties have been established in two Minnesota locations. The Researcher will coordinate the planting, inoculation, and disease phenotyping of these nurseries. Data for released cultivars will be made publicly available at the conclusion of the season. The Cooperator currently houses an extensive collection of over 650 Xanthomonas strains, acting as a resource for researchers in the bacterial leaf streak community to deposit or request strains. The cooperator will maintain and expand this resource through collection and isolation of strains from naturally infected material. This work includes characterization of Xanthomonas translucens isolates through molecular and in plant assays. A sub-set of five strains per year will be selected, based on preliminary molecular typing, for whole genome assembly and annotation to track genetic diversity in current Xanthomonas translucens populations. The Researcher will coordinate a two-day conference of researchers, growers, and industry representatives to identify priority areas and facilitate synergies in the bacterial leaf streak research community. The PostDoc will work with the USDA scientist to use molecular cloning tools to generate constructs for wheat transformation. The USDA scientist will facilitate plant transformation at a plant transformation facility. Constructs will be tested in wheat protoplasts while transgenics are being generated. PostDoc will extract high molecular weight DNA from the bacterial leaf streak resistant wheat cultivar Boost. DNA will be used as input for long-read enrichment sequencing targeting ~1,000 known disease resistance gene clusters. Genomic sequence data from Boost will be de novo assembled and compared to published wheat genomes to determine diversity at these disease resistance gene loci. Current long read sequencing also allows determination of DNA methylation status – an important indicator of gene expression potential. The postdoc will generate DNA methylation data over a time-course of Xanthomonas infected wheat plants, develop a computational pipeline to monitor methylation changes, and identify regions of the genome with displaying differential methylation. RNA sequencing data will be generated from the same tissue to associate gene expression changes with DNA methylation changes and identify novel candidate breeding targets