Start Date: Oct 01, 2010
End Date: Jul 29, 2013
We have soybean genotypes resistant to one or more rust isolates, but susceptible to all others. These soybean genotypes will be challenged with specific pathogen isolates to study the resistance and susceptible response. Gene and protein expression in both plants and pathogens will be monitored using microarrays, membrane arrays, expressed sequence tag analysis, in situ hybridization, and RT-PCR. Proteins will be detected by liquid chromatography-tandem mass spectrometry (LCMS/MS). Cell fractionation, laser capture microdissection, and subtractive hybridization will be used to isolate specific tissues, organelles, or materials involved in disease processes or responses. Other methods such as antibody localization, gene silencing, plant hairy root transformation (for SCN studies) and mutant analysis will be used to determine the function of genes and proteins and to evaluate their importance in resistance and susceptibility. The disease and pest resistance responses to infection in soybeans will be elucidated systematically using microarrays, proteomics and metabolomics to resolve the biological network evoked. A comparison of differential gene expression and protein accumulation in the resistant and susceptible response of soybean to pathogens will identify components of the network. These networks will be built, examined, and perturbed to confirm function of components using an array of tools, including bioinformatics, yeast two-hybrid screens, mutation analysis, immunolocalization, immuno-precipitation, affinity purification, protein tagging, gene over-expression, phage library display, and other methods that will resolve proteinprotein interactions and interactions among molecules. Based on these data, we can identify candidate members of pathways and networks involved in signaling and evoking the resistance response. Other plant systems, including common bean and Medicago truncatula, will be used as needed in parallel investigations studying host-pathogen responses and interactions to take advantage of the knowledge and specific traits of the resistance response in these systems. Approaches for achieving pathogen control include engineering transgenic plant tissue and organs to express genes that boost the natural defense system of the plant or to provide the plant with a new trait that confers resistance by blocking pathogen attack or survival. Genes shown to have important roles in plant defense may be over-expressed in transgenic plants. Likewise genes that are critical to survival of the SCN in the host or that make the plant susceptible to SCN may be silenced in transgenic roots using hairy root transformation techniques. Additionally, genes that express antibodies or protein antagonists will be engineered into soybean to block the survival and development of the pest or pathogen.