2014
Virus-induced Gene Silencing (VIGS) to Reveal Signal Networks Against Genes Controlling Resistance to Soybean Stress - Soybean Rust (ASR) and, Sclerotinia White Mold (1420-532-5604)
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
(none assigned)
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Steve Whitham, Iowa State University
Co-Principal Investigators:
John Hill, Iowa State University
Mehdi Kabbage, University of Wisconsin
Kerry Pedley, USDA/ARS-Fort Detrick, MD
Michelle Graham, USDA/ARS-Iowa State University
+3 More
Project Code:
1420-532-5604
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

Unique Keywords:
#genetic resistance to diseases, #soybean diseases, #soybean gene expression, #virus-induced gene silencing
Information And Results
Project Deliverables

We expect results of this and complementary projects will benefit a wide variety of stakeholders from genomics researchers to producers. Benefits include:
• Expansion of the knowledge base to needed to rationally improve genetic control of soybean disease resistance. This is likely through identification of “hubs” that regulate resistance to numerous stress-causing agents of soybean. The information is expected to increase the yield potential of soybeans as well as quality of the product.
• Provide information to soybean breeders for development of markers for development of germplasm with enhanced resistance to stresses for the breeding of improved soybean varieties. Ultimately, soybean producers will directly benefit from results of this research and the soybean improvement that is expected to result will increase the competitiveness of the soybean.
• BPMV constructs and transgenic plants that will be available to soybean researchers. Distribute constructs maintained in this library to leverage soybean research. This will provide enabling technology to soybean researchers to discern genetic control of important traits in soybean.
• Enable collaboration among the nation’s premier soybean research scientists to conduct genetic research that will improve the soybean. Coordinate research through biennial meetings to allow discussion of results and analyze solutions to challenges.
• Potential novel S. sclerotiorum control tool if BPMV VIGS can be used to silence genes in the fungus. This would enable silencing of essential fungal genes, which would be lethal to the pathogen and thus prevent infection.

Final Project Results

Achieving the objectives:
• In the area of Asian soybean rust research, 7 VIGS constructs designed to silence hub genes for Rpp2 resistance were tested; none showed a reduction in resistance, suggesting that either the genes were not sufficiently silenced or they do not play a role in Rpp2 mediated resistance. Work on Rpp3 is nearly complete. A VIGS construct designed to silence 5 candidate TIR-NBS-LRR resistance genes on chromosome 6 yielded a loss of resistance phenotype. In order to determine the genes in the Rpp1 locus, a BAC library of the DNA region was isolated and sequenced, revealing 3 candidate NBS-LRR genes. VIGS is being done to silence these genes.
• Transgenic plants that over express selected transcription factor genes (WRKY36 and MYB84) thought to be important for soybean disease resistance are being progressed to expression testing of the transgenes in the plants.
• Work continues in screening genes for responses in white mold, or Sclerotinia sclerotiorum infection. Several hub genes are being tested in the variety Traff, which has tolerance to BPMV and a predictable reaction to S. sclerotiorum. Three genes were shown to enhance resistance when silenced. Additional tests are underway, some of which are promising, particularly for NADPH oxidase genes. Classes of genes that are either upregulated or down regulated in susceptible versus resistant interactions were identified.

Not achieving the objectives:
• None at this time.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.