Identify the mechanism used by Fusarium virguliforme to cause sudden death syndrome in soybean;
Leonor Leandro ( Iowa State University), Madan Bhattacharyya ( Iowa State University) ($65601). The Project Manager's email is firstname.lastname@example.org.
Key Words: Fusarium virguliforme, Sudden Death Syndrome (SDS)
F. virguliforme is a highly destructive pathogen. It causes sudden death syndrome (SDS) in soybean. The estimated average annual soybean yield suppression from this pathogen is valued at $150 million. Although a major emphasis of soybean breeding programs has been to look for major genes that confer SDS resistance, the outcome has not been as successful as for other diseases such as Phytophthora rot and stem rot, and soybean cyst nematode (SCN). Therefore, it is becoming urgent to create soybean germplasm carrying novel, broad-spectrum SDS resistance developed through biotechnological approaches. To facilitate development of such germplasm, we must have a better understanding of the mechanism used by F. virguliforme in causing SDS. Thus, our long-term goal has been to understand the mechanisms used by the pathogen to cause SDS and then use that knowledge in creating SDS-resistant soybean cultivars. The following research objectives will be accomplished in achieving the long-term goal of this proposal: • Identify candidate F. viguliforme pathogenicity genes involved in SDS development; • Mutate the candidate F. virguliforme pathogenicity genes by conducting homologous recombinations; • Determine the phenotype of the F. virguliforme mutants that carry mutated candidate pathogenicity genes; and • Conduct complementation analysis of mutants to identity pathogenicity genes. This is a continuing project that has identified 92 genes that are highly expressed only in infected soybean root and not in germinating spores or mycelia. The research team has classified these genes for their possible function and are now in the process of mutating specific genes to determine their role in causing SDS disease symptoms.
This project is funded by Indiana Soybean Alliance