1a. Objectives (from AD-416):
Soybean yields are affected quantitatively and qualitatively by fungi, insects, nematodes, and viruses. The ability of pathogens and pests to colonize and/or infect soybean plants is the result of interactions of pathogen and host genes that allow pathogenic organisms to reproduce and cause disease. The objective of this cooperative research project is to identify and characterize the expression of soybean and pathogen genes involved in the establishment and/or maintenance of disease-causing interactions.
1b. Approach (from AD-416):
Candidate soybean genes that support/permit pathogen accumulation or that are involved in pathogenesis will be identified through the genetic analysis of soybean lines differing in their susceptibility to pathogens and pests. In addition, genes expressed at the host-pathogen interface will be identified and characterized using genetic and expression profiling techniques. The involvement of the genes in disease will be confirmed by gene-specific complementation and/or gene silencing. Pathogen genes will be identified by similar genetic and expression profiling techniques. Host and pathogen proteins that physically interact in diseased cells will be identified through in vivo interaction studies and in vitro protein binding and affinity chromatography analyses.
3. Progress Report:
Novel viruses were discovered in the fungi that cause charcoal rot (Macrophomina phaseolina) and white mold (Sclerotinia sclerotiorum) of soybean. Charcoal rot and white mold are two damaging diseases of soybean for which high levels of resistance have not yet been identified. Hence, these viruses have the potential to reduce the severity of disease symptoms induced by the fungi in soybean and could be developed into tools to help mitigate losses caused by the diseases. The effects of the viruses on the virulence of the fungi they infect are being investigated. High-throughput sequencing was used to detect and monitor the prevalence of viruses infecting soybean in Illinois and North Dakota. The analysis showed that the incidence of viruses changes significantly each year and identified a new soybean-infecting virus and a new virus infecting a soybean-associated insect species.