J.R. Alfano

The Alfano lab is associated with the Department of Plant Pathology and the Center for Plant Science Innovation at the University of Nebraska - Lincoln.

Members of our research team study the strategies bacterial pathogens employ to cause diseases on plants. As a model system we study the gram-negative bacterial plant pathogen Pseudomonas syringae and its interactions with plants. An important feature that P. syringae has that allows it to grow in plants and sooner or later cause disease is a protein secretion system called the type III protein secretion system. This protein secretion system is found in many gram-negative bacterial pathogens of both plants and animals and other bacteria in close associations with eukaryotic organisms. The truly remarkable characteristic of type III systems is that they not only secrete proteins from the bacterial cell, but they also inject or translocate bacterial proteins into eukaryotic cells.
Our main research focus is to understand how type III secretion works and to determine what the translocated proteins (known as type III effectors) are doing inside the plant cell to favor parasitism. Relatively recently, we and others have found that type III effectors suppress plant innate immunity and, therefore, several of our projects are focused on how these proteins are capable of suppressing plant innate immune responses. We expect that this line of research will identify new components of plant immunity some of which might not be discovered using conventional approaches. Therefore, we view type III effectors as tools to explore the plant innate immune system.