Updated May 3, 2026:
This is the final report of the FY25 project, the 3rd year of a three-year project, entitled SoyRenSeq: a novel approach for disease resistance gene discovery and application for soybean improvement. The central goals of this collaborative, multi-state, and multi-disciplinary project are to explore, apply, and optimize the RenSeq technology for accelerated identification of candidate disease resistance genes (so-called R genes) responsible for resistance to various soybean pathogens prevalent in the Mid-west region, and for accelerated development of disease-resistant soybean cultivars by precise R gene selection. Five specific objectives were proposed to achieve our whole project goals through FY23-FY25: 1) Development of a high-quality RenSeq platform for the soybean research community; Sequencing and assembly of NBS-LRR gene clusters in major soybean lines carrying resistance to prevalent soybean pathogens in the Midwest region; 3) Analysis of R gene expression and responses to various soybean pathogens; 4) Evaluation of resistance to various pathogens and mapping of major R genes and QTL; and 5) Development of candidate R-gene-based molecular markers for precision breeding. Objectives 1 and 2 were fully achieved in FY23 and FY24, while Objectives 3-5 were continuous and completed by the end of the whole project. This FY25 project was extended to March 31, 2026; thus, two semi-annual reports had been provided previously. Given that the extended period of this FY25 project overlaps with the first half year of the FY26 project, there were some common experiments conducted to achieve research goals defined in both projects. In this final report, we intended to keep concise in describing research activities conducted during the FY25 period, but present more detailed project results, deliverables, and key performance indicators through the activities made to achieve objectives 3-5 in the FY25 project, etc.
Activities to achieve objective 3 mainly focused on analyses of changes in expression levels of candidate disease resistance (R) genes in response to various pathogens. The expression level of gene refers to the relative abundance of its final products for a specific trait. In general, a gene responsible for resistance to a particular pathogen exhibit altered levels of expression upon infection by that pathogen. In other words, a structurally defined R genes showing changed expression level upon a pathogen infection is considered as a strong candidate for disease resistance. We performed this type of analyses, using a technique call qRT-PCR, to detect candidate genes for resistance to several pathogens, including Phytophthora sojae (PIs Ma and Bhattacharyya) and Phytophthora sansomeana (co-PIs Wang/Lin) causing Phytophthora root and stem rots, Fusarium graminearum (co-PI Cai) causing Fusarium root rot and seedling blight, as well as Sclerotinia sclerotiorum (co-PI Lorenz) causing white mold. Additionally, Lorenz lab have collected a set of plant tissues from plants inoculated and un-inoculated with Sclerotinia sclerotiorum, which allows genome-wide detection, using a technology called RNA-sequencing, of all genes whose expression levels respond to the pathogen to gain new insights into this important, but not-yet-well-understood disease - white mold. Lorenz and Ma lab plan to continue this effort through the FY26 SoyRenSeq II project. Ma, Wang, and Bhattacharyya labs further examined the expression patterns of candidate genes for Rpsan1, Rps12, Rps13, Rps14, Rps15 and Rps16, laying the foundation for design DNA markers for precise selection of these resistance genes.
Major deliverables from objective 3 include 1) Enhanced understanding of soybean plants’ responses to several destructive soybean pathogens that haven’t been well characterized previously; 2) Identified strong candidate R genes for resistance to those pathogens.
Activities to achieve objective 4 mainly focused on evaluation or re-evaluation of soybean resistance to several pathogens and genetic approach to further delimit the candidate disease resistance genes or QTL to smaller chromosomal regions. Co-PI Wang at Michigan State University and co-PI Lin at University of Missouri continued genetic mapping of candidate genes for Rpsan1 with a newly developed a large mapping population using a set of molecular markers for finer-scale mapping of Rpsan1. Wang and Lin labs also developed a mapping population for identification of gene(s) conferring resistance to frogeye leaf spot. Lin lab made crosses of Rps11 and Rps14 donor lines with five breeding lines chosen from his breeding program, separately. Lin further advanced F4-derived mapping populations for an additional generation in the field for dissecting Stink Bug resistance and Cercospora Leaf Blight resistance and has made progress on initial QTL mapping. Moreover, Lin lab found that PI 594527 shows resistance to both P. sojae and P. sansomeana and obtained seeds from a cross between this line and a breeding line in his program. In general, soybean genes conferring resistance to P. sojae does not carry resistance to P. sansomeana; thus, the identified dual resistances carried by PI 594527 provided a unique opportunity for further dissection of the dual resistances for both pathogens. Bhattacharyya lab fine mapped Rps12 and Rps13 to chromosome 18, loosely linked to Rps 4, 6 and 13 loci, and conducted allelic test to determine whether these genes are distinct loci or different alleles of a same gene locus. Hundreds of recombinant lines have been genotyped with a panel of SNPs from progeny derived from crosses between varieties carrying these genes. Parental lines have been sequenced using a long-read sequencing platform provided by the Oxford Nanopore Technologies. The analysis has revealed considerable variation in the productivity of individual plants, as well as interactions among these genes, which affect seed yield per plant. Lorenz lab continued development of genetic mapping population for wild mold resistance QTLs and for Brown Stem Rot resistance QTL during this past soybean growing season, and continued evaluation of these lines carrying the resistance QTLs with additional pathogen isolates. Several advanced breeding lines showed strong resistance to these newly texted races and were used in breeding at Minnesota. Ma lab coordinating with Lin lab assessed a gene-editing line and found it gas gained resistance to P. sansomeana. Ma lab coordinating with Cai lab assessed a gene-editing line and found it gas gained resistance to P. sansomeana. Cai lab at USDA-ARS identified major QTL underlying Fusarium graminearum resistance and published the work in a peer-reviewed journal. Additionally, Cai lab assessed gene-editing lines created by Ma lab for frogeye spot. Miranda lab at NDSU continued advancing mapping population for resistances to white mold and brown stem rot and received F5 seeds in the fall of 2025 for mapping.
Major deliverables from objective 4 include 1) Fine-mapped key resistance loci (Rpsan1, Rps12, Rps13) using large mapping populations, dense SNP markers, allelic tests, and long-read sequencing to resolve locus relationships and narrow candidate regions; 2) Developed and advanced multiple mapping populations for resistance to frogeye leaf spot, white mold, brown stem rot, wild mold, stink bug, and Cercospora leaf blight, with initial QTLs identified; 3) Identified novel resistance sources and genetic interactions, including dual resistance to P. sojae and P. sansomeana and yield-related interactions among resistance loci; 4) Validated resistance in gene-edited lines (notably for P. sansomeana) and evaluated edited materials for additional diseases such as frogeye leaf spot; 5) Discovered and published major QTL for F. graminearum resistance and identified advanced breeding lines with strong resistance to emerging pathogen races.
Activities to achieve objective 5 have been continued efforts over the years in these major breeding programs over the years. In this project, we particularly focused on newly identified and more effective genes and/or QTLs for resistance to the major pathogens identified in this project. Lorenz and Bhattacharyya labs have developed markers for Rps6. Ma and Bhattacharyya labs have developed DNA markers for Rps11, Rps 12, Rps13, and Rps15. In addition, Ma lab has been leveraging gene-expression data from the candidate gene for a particular pathogen to test potential linkage between gene-based markers and disease resistance gene/QTL. All labs have leveraged the funding from this project to enhance the gene discovery pipelines and/or breeding programs.
Major deliverables from objective 4 include 1) Created DNA markers for Rps6, Rps11, Rps12, Rps13, and Rps15 resistance genes; Identified and prioritized new, highly effective genes and quantitative trait loci (QTLs) for major pathogen resistance; 3 Leveraged gene-expression data from candidate genes.
Benefits to soybean producers: Soybean diseases cause approximately 11% annual yield losses across the US, making disease-resistant cultivars the most economical, environmentally friendly solution for producers. This project accelerates discovery of key resistance (R) genes and development of precise molecular markers that enable breeders to stack multiple R genes into elite soybean lines for broad-spectrum, durable protection against threats like sudden death syndrome, Phytophthora root rot, frogeye leaf spot, and others, and ultimately benefit soybean producers through reduced application fungicides and increased soybean yields. All labs trained either graduate students or postdoctoral scientists, as well as undergraduate students through this project.
Publications:
Detranaltes, C., Quigley, C., Song, Q., Ma, J. and Cai, G., 2025. Identification of a Quantitative Trait Locus on Chromosome 15 Conferring Resistance to Pythium irregulare in Soybean. PhytoFrontiers™, pp.PHYTOFR-05.
Detranaltes, C., Quigley, C., Song, Q., Ma, J. and Cai, G., 2025. A Novel Quantitative Trait Locus Reduces Fusarium graminearum Infection in Glycine max Seedlings. Phytopathology®, 115(6), pp.666-675.
Xu, Z., Chen, K., Medina-Culma, C., Lee, Y., Girma, G., Lorenz, A., Kurek, A., Cannon, S.B., An, Y. and Beavis, W., 2025. Synergetic Gene Networks Controlling Soybean Sudden Death Syndrome. CANVAS 2025.
Dangal, N.K., Ernat, E.M., Adee, E.A., Betts, A.K., Bish, M., Bissonnette, K.M., Bradley, C., Byamukama, E., Byrne, A.M., Chilvers, M.I. and Faske, T.R., … Wang, D.,m Wiggs, S.H., Yabwalo, D., and Muller, D.S. 2025. Soybean Seed Treatment Evaluation under Various Levels of Sudden Death Syndrome and Populations of Soybean Cyst Nematode. Plant Disease, (ja).
View uploaded report 2 
This project focused on helping soybeans better resist major diseases by identifying and refining the genes that protect plants from infection and using that knowledge to improve breeding. Researchers studied how certain “resistance genes” behave when plants are attacked by pathogens to identify candidate genes that potentially can be used for protecting the plant. The team examined soybean responses to several damaging diseases, including root rots, seedling blight, and white mold, and also used broader genome-wide approaches to discover new genes involved in defense. At the same time, they created and analyzed large plant populations to narrow down where these resistance traits are located in the genome, making it easier to pinpoint the exact genes responsible. This work included developing new breeding populations, identifying regions linked to resistance for multiple diseases, and discovering unique cases such as a soybean line that can resist two different pathogens at once—something rarely seen and especially valuable for future breeding. The team also explored how different resistance genes interact with each other and how they may affect yield, which is important for ensuring that disease-resistant plants remain productive. Advanced tools, including gene editing and long-read DNA sequencing, were used to identify candidate genes and better understand genetic variation. Several gene-edited lines showed improved resistance, demonstrating the potential of precise genetic approaches. In addition, the researchers developed DNA markers, simple genetic “tags”, for key resistance genes so breeders can quickly identify and combine multiple protective traits into new soybean varieties. Altogether, the project delivered a clearer understanding of how soybeans defend themselves, identified strong candidate resistance genes, refined their genomic locations, and provided practical tools for breeding programs. These advances are expected to help develop soybean varieties with broader and more durable resistance to disease, reducing reliance on chemical treatments and improving yields for farmers. The project also supported training for students and early-career scientists, contributing to the next generation of agricultural research.