Plant Pathogen Interactions:

    In nature plants are exposed to a variety of biotic and abiotic stresses. Viruses, bacteria, fungi, nematodes and other pests and pathogens attack plants and are biotic stresses to plants, while flooding, drought, salinity, are abiotic stresses.  These present the plant with challenges that they must endure to survive.  Plants have evolved numerous, complex, adaptive mechanisms to resist pests and pathogens and to tolerate environmental assaults. These mechanisms provide crucial protection to the plant against stresses to ensure plant survival.  Identifying the genes and understanding the biochemistry, pathways and mechanisms producing resistance to a specific stress is important to developing new, broader resistances to plant stresses.

    In this collaboration several USDA scientists are comparing the expression of genes found in resistant and susceptible soybeans in response to viral, bacterial, and fungal pathogens in addition to those expressed upon invasion by the soybean cyst nematode.  The goal of this group is to identify the genes involved in resistance of plants to different biotic stresses and determine the function of these genes. By examining the soybean response to different pests and pathogens, we hope to dissect response pathways and identify genes and pathways uniquely expressed in response to certain stresses, while identifying other genes and pathways that may play a more general role in resistance.  Initially, we will be studying the expression and function of soybean genes involved in resistance to soybean mosaic virus, Pseudomonas (bacterial blight), Fusarium and soybean cyst nematodes.  New tools and strategies will result from this research that will allow scientists to broaden and strengthen resistanace of plants to different pests and pathogens.

    This research requires the cooperation of a number of other USDA scientists including John Hammond (soybean Mosaic Virus), Jacyn Baker (Pseudomonas), Brian Bailey (Fusarium), Mark Tucker (promoter analysis) and Bob Yaklich (analysis of SCN invasion using microscopy).